THI NA TO DAUS009844599B2 UN DARIMATUTULOTTUK (12 ) United States Patent ( 10) Patent No. : US 9 ,844 , 599 B2 Satyam (45 ) Date of Patent: Dec . 19, 2017 (54 ) NITRIC OXIDE RELEASING PRODUGS OF C07C 201/ 04 (2013 . 01 ) ; C07C 203 /04 THERAPEUTIC AGENTS (2013 . 01 ) ; C07C 227/ 18 (2013 . 01 ) ; C07C 229 /42 ( 2013 .01 ) (71 ) Applicant: Apparao Satyam , Mumbai ( IN ) (58 ) Field of Classification Search CPC . .. C07C 201 /00 ; C07C 203 /00 ; C07C 201 /04 ; (72 ) Inventor: Apparao Satyam , Mumbai ( IN ) A61K 31 /21 ; A61K 4 /4817 ; A61K 31 /60 ( * ) Notice : Subject to any disclaimer , the term of this USPC .. . . . 514 / 161, 162 , 165 , 166 , 509 patent is extended or adjusted under 35 See application file for complete search history . U . S .C . 154 (b ) by 0 days. (56 ) References Cited ( 21 ) Appl. No. : 14 / 761, 887 U . S . PATENT DOCUMENTS ( 22 ) PCT Filed : Jan . 17, 2014 6 ,610 ,676 B18 /2003 Del Soldato ( 86 ) PCT No. : PCT / IN2014 /000033 6 ,613 ,784 B1 9 /2003 Benedini et al. $ 371 (c ) ( 1) , (Continued ) ( 2 ) Date : Jul. 17 , 2015 FOREIGN PATENT DOCUMENTS (87 ) PCT Pub . No. : WO2014 /111957 CN 1966484 A 5 /2007 CN 101053662 A 10 / 2007 PCT Pub . Date : Jul. 24 , 2014 (Continued ) (65 ) Prior Publication Data OTHER PUBLICATIONS US 2015/ 0328323 A1 Nov. 19, 2015 International Search Report for PCT Application No . PCT/ IN2014 / ( 30 ) Foreign Application Priority Data 000033 , dated Jun. 5 , 2014 , 3 pages . Jan . 21 , 2013 ( IN ) ...... 181/ MUM / 2013 (Continued ) (51 ) Int. CI. Primary Examiner — Janet L Coppins A61K 31/ 21 ( 2006 . 01 ) (74 ) Attorney , Agent, or Firm — Sreenivasarao Vepachedu A61K 31 /60 ( 2006 .01 ) C07D 201 / 04 ( 2006 .01 ) ( 57 ) ABSTRACT A61K 47/ 48 ( 2006 .01 ) C07C 229 /42 ( 2006 . 01 ) The present invention relates to nitric oxide releasing pro C07C 201 /04 ( 2006 .01 ) drugs of known drugs or therapeutic agents wherein the drug C07C 227 / 18 ( 2006 .01 ) or therapeutic agents contain at least one carboxylic acid A61K 31/ 216 ( 2006 .01 ) group . The invention also relates to processes for the prepa ( Continued ) ration of these nitric oxide releasing prodrugs, to pharma (52 ) U . S . CI. ceutical compositions containing them and to methods of CPC ...... A61K 47 /481 (2013 .01 ) ; A61K 31/ 21 using these produgs. ( 2013 .01 ) ; A61K 31/ 216 ( 2013 .01 ) ; A6IK 31/ 60 ( 2013 .01 ) ; A61K 31/ 621 ( 2013 .01 ) ; 6 Claims, 12 Drawing Sheets

1A )

Plasmasalicylatewg/ml)S.EM,n3)

(Mean

Time (h ) + Aspirin (30 mg/ kg p .o .) + - D1 -R1 (44 . 83 mg /kg p . o . + 1- D1 - R2 ( 47 .16 mg/ kg p . o .) - | -D1 -R3 (49 . 49 mg/ kg p . o . IB ) 125 91. 13 1 12. 2 89 .78 10 . 2 73. 54 4 . 9 T 53 . 00 15 . 6 AUG(pgWM) (MeantS.EM,n=3) $

Aspirin(30 mg P7097 /kg p (.o44 .). 83 mg P7244 /kgp .(49o. ). 49 maig P7245 p.(o47 .) . 16mging p.o .)

Oral absorption profile of aspirin and its prodrugs I- DI- R1 ( i. e. , P7097) , 1- D1 - R2 ( i. e ., P7244 ) and I- DI- R3 (i . e. , P7245 ) in SD Rats ; A ) Line graph ; B ) Bar graph , US 9 ,844 ,599 B2 Page 2

(51 ) Int . Cl. Kubes, Paul & Wallace , John L ., Nitric Oxide as a Mediator of A61K 31 /621 ( 2006 .01 ) Gastrointestinal Mucosal Injury ? — Say it ain 't so ; Mediators of C07C 203 /04 (2006 . 01 ) Inflammation , 1995 ; 4 : 397 -405 . Kulkarni, S . K . , Jain , N . K . , Singh , A . , Nitric Oxidxe -releasing NSAIDs : A new dimension in nonsteroidal antiinflammatory drugs ; ( 56 ) References Cited Drugs of the Future 2001; 26 ( 5 ) : 485 . ( Abstract only ) . U . S . PATENT DOCUMENTS J . E . Keeble and P . K . Moore, Pharmacology and potential therapeu tic applications of nitric oxide - releasing non - steroidal anti- inflam 7 , 199 ,154 B2 * 4 / 2007 Berthelette ...... C07C 317 / 46 matory and related nitric oxide -donating drugs. British Journal of 514 / 509 Pharmacology , 2002 ; 137 ( 3 ) : 295 -310 . (Article first published 7 ,220 ,749 B2 5 /2007 Letts et al . online : Feb . 2 , 2009 ) ( Abstract only ) . 7 , 524 , 836 B2 4 / 2009 Del Soldato Muscara M . N ., Wallace J . L . ; Nitric Oxide, V . Therapeutic potential 2006 /0058363 A1 3/ 2006 Wang et al. of nitric oxide donors and inhibitors, American Journal of Physi 2008 /0293781 AL 11/ 2008 Gasco et al. ology , Gastrointestinal and liver physiology , 1999 ; 39 : G1313 - 1316 . 2011/ 0263526 A1 * 10 /2011 Satyam ...... C07C 203 / 04 Berguad et al . , Nitric Oxide -Releasing Drugs A Novel Class of 514 /50 Effective and Safe Therapeutic Agents, Ann . N . Y . Acad . Sci ., 962 : 360 - 371, 2002 . (Abstract only ) . FOREIGN PATENT DOCUMENTS S Fiorucci , P Del Soldato , NO -aspirin : mechanism of action and gastrointestinal safety , Dig Liver Dis 2003 ; 35 ( suppl. 2 ), 9 - 19 . EP 0722434 B1 7 /1996 EP 1219306 A1 7 / 2002 ( Abstract only ) . WO 9530641 AL 11 / 1995 Lirk , P ., Hoffmann , G ., and Rieder , J . , Inducible nitric oxide WO 9716405 A1 5 / 1997 synthase time for reappraisal , Curr . Drug Targets Inflamm . WO 9809948 A2 3 / 1998 Allergy , 2002 ; 1 : 89 - 108 . ( Abstract only ) . WO 9821193 A1 5 / 1998 Ian L Megson , David J Webb , Nitric oxide donor drugs: current WO 9858910 Al 12 / 1998 status and future trends, Expert Opin . Investing . Drugs, 2002 ; 11 ( 5 ) : WO 2001010814 A1 2 / 2001 587 -601 . ( Abstract only ) . WO 2003084550 AL 10 / 2003 Press reports on naproxcinod and NCX4016 , www .nicox . com ; WO 2003094923 AL 11 / 2003 2014 . WO 2004004648 A2 1 / 2004 Nemmani, Kumar V . S . et al ., NO -NSAIDs : Gastric -sparing nitric WO 2004020384 A1 3 / 2004 oxide releasable prodrugs of non -steroidal anti - inflammatory drugs , WO 2004035042 A1 4 /2004 Bioorganic & Medicinal Chemistry Letters 19 (2009 ) , 5297 - 5301. WO 2004105754 Al 12 / 2004 WO 2005011646 A2 2 /2005 Pathan , A . R ., et al. , Oral bioavailability , efficacy and gastric WO 2005030224 A1 4 / 2005 tolerability of P2026 , a novel nitric oxide - releasing diclofenac in WO 2005070868 A1 8 / 2005 rat , Inflammopharmacology , 2010 , 18 ( 4 ) , 157 - 168 . ( Abstract only ) . WO 2007054451 A1 5 / 2007 O . A . al - Swayeh et al. , A comparison of the anti - inflammatory and WO 2007088123 A2 8 / 2007 anti -nociceptive activity of nitroaspirin and aspirin , British Journal WO 2007099548 A1 9 / 2007 of Pharmacology (2000 ) 129 , 343 - 350 . WO 2008095809 AL 8 /2008 Lanas , Angel, Role of nitric oxide in the gastrointestinal tract , WO 2009000592 A1 12 / 2008 Arthritis Research & Therapy 2008 , 10 (Suppl 2 ) : S4 , Oct. 17 , 2008 . Dermot Cox et al, Effect of enteric coating on antiplatet activity of low - dose aspirin in healthy volunteers , Stroke 2006 ; 37 ( 8 ) : 2153 - 8 . OTHER PUBLICATIONS Patrignani, Paola et al. , Selective Cumulative Inhibition of Platelet Hyo -Kyung Han and Gordon L . Amidon , Targeted Prodrug Design Thromboxane Production by Low - dose Aspirin in Healthy Subjects , to Optimize Drug Delivery , AAPS PharmSci 2000 , 2 ( 1 ), Mar . 21, American Society for Clinical Investigations 69 , Jun . 1982 , 1366 2000 . 1372 . Symposium on “ New Anti - inflammatory agents : NO -NSAIDs and Esser , Ronald et al. , Preclinical pharmacology of lumiracoxib : a COX - 2 inhibitors” part of the 11th international conference on novel selective inhibitor of cyclooxygenase - 2 , Br. J . Pharmacol. “ Advances in prostaglandin and leukotrine research : Basic science 2006 , 144 , 538 -550 . (Abstract only ). and new clinical applications” held in Florence ( Italy ) , Jun . 4 - 8 , Gund , Machindra et al ., Gastric -sparing nitric oxide releasable 2000 . ' true ' prodrugs of aspirin and naproxen , Bioorganic & Medicinal Menlo Bolla et al. , Therapeutic Potential of Nitrate Esters of Chemistry Letters 24 ( 2014 ), 5587 -5592 . Commonly Used Drugs, Curr. Topics Med . Chem . 2005 ; 5 : 707 720 . (Abstract only ) . * cited by examiner U . S . Patent Dec . 19 , 2017 Sheet 1 of 12 US 9 ,844 , 599 B2

S

Plasmasalicylate(ng/ml) À (MeanS.EM,n=3)

Time (h ) + Aspirin (30 mg/ kg p .o .) • 1- D1 - R1 (44 .83 mg/ kg p . o .) 1 -D1 - R2 (47 . 16 mg/ kg p . o .) + 1- D1 - R3 (49 . 49 mg/ kg p . o .) IB )

91 .13 $ 12 .2 89 .78 10 . 2

73 . 54 + 4 . 9 53 . 56 $ 15 . 6 AUC(ug*h/mi) (MeanS.EM,n=3) ñ

ñ

Aspirin(30 mg P7097 /kg p.( 44o . ). 83 mgP7244 /kg p.( o49 . ). 49 mg P7245 /kg p.( o47. ) . 16mg /kg p. o. )

Figure 1. Oral absorption profile of aspirin and its prodrugs I- D1 - R1 (i . e ., P7097) , I -D1 - R2 ( i. e ., P7244 ) and I -D1 - R3 ( i . e . , P7245 ) in SD Rats ; A ) Line graph ; B ) Bar graph . U . S . Patent Dec . 19 , 2017 Sheet 2 of 12 US 9 ,844 , 599 B2

2A )

Plasmasalicylate(ug/ml) (Mean-S.EM,n=3)

- Time (h ) + Aspirin ( 30 mg/ kg p . o . ) * 1- D1 - R1 ( 44 .82 mg/ kg p . o .) 2B ) 500 436 . 8 £ 26 . 2 397 .6 # 28 .0

AUC(ug*h/ml)(MeanS.EM,n=3)

Aspirin(30 mg /kg po )I -DI -R1 (44 . 82 mg /kg p. o. )

Figure 2 . Oral Absorption profile of aspirin and its prodrug I -D1 - R1 in Wistar Rats ; A ) Line graph ; B ) Bar graph . U . S . Patent Dec . 19, 2017 Sheet 3 of 12 US 9 ,844 , 599 B2

3A )

Plasmanaproxen(ug/ml) (Mean+SEM,n=3) Ø

?

o Time (h ) ta + Naproxen ( 10 mg/ kg ) * 1 -D2 - R1 (13 .87 mg/ kg ) * 1- D2 - R3 ( 15 .07 mg /kg ) + 1- D2 - R2 ( 14 .47 mg/ kg ) * 1- D2 - R4 ( 15 .69 mg/ kg ) 3B ) 272 . 6 £ 8 . 5 3007 * * 1207. 8 18 . 2

S.EM,n=3) 182 .7 8 . 1 178 . 6 + 8 . 1 177 . 4 4 . 1 AUC(ug*h/ml) 100 (Mean

filmNaproxen(10 mg /kg ) P7135(14 . 47 mg /kg ) P7133(13 . 87 mg /kg ) P7134(15 . 07 mg P7132 /kg ) ( 15 . 69 mg /kg)

* * p < 0 . 01 versus Naproxen Figure 3 . Oral absorption profile of naproxen and its prodrugs I -D2 - R1 ( i . e . , P7133 ) , 1 -D2 - R2 ( i. e . , P7135 ) , I - D2 -R3 ( i. e . , P7134 ) and I -D2 - R4 ( i . e ., P7132 ) in SD Rats ; A ) Line graph ; B ) Bar graph . U . S . Patent Dec . 19 , 2017 Sheet 4 of 12 US 9 ,844 , 599 B2

PlasmaNOX(UM)(Pooleddata,n=3)

Time (h ) + Vehicle (PEG 400) + 1- D1 - R1 ( 14 . 94 mg/ kg ) + 1- D2 - R1 (41 . 60 mg/ kg )

Figure 4 . Plasma NOx (nitrate /nitrite ) levels following oral administration of prodrugs I -D1 R1 and I- D2 -R1 in rats . U . S . Patent Dec. 19 , 2017 Sheet 5 of 12 US 9 ,844 , 599 B2

5A ) Gastric Ulcer Study of Aspirin and its Prodrug I -DI - R1 in Rats * * * * * * * * * ** * * * * * .

...... Vehicle ( 0 . 5 % CMC- )- . . . . the TEL . . tok . : ** fromht, date Aspirin ( 100 mg / kgp . o . ) r es EUR * * * * ** *

HiFi : , , I - DI -RI (NO - aspirinat 298 . 85 ing /kg p . o . ) 5B ) 150 93 # 32

GastricLesion&UlcerArea(mm) (MeanIS.EM)

1 # 1 * * * . . . Aspirin(200 mgkg po ) Oy p709729885 moho po )

* * * 0 . 0001 versus Aspirin

Figure 5 . A ) Images of rat stomachs showing gastric lesion and ulcer induction / sparing following acute oral administration of aspirin ( 100 mg/ kg ) and its promising prodrug I -DI - R1 ( i . e ., P7097 or NO -aspirin ) at 298 . 85 mg/ kg , which is a dose equimolar to 200 mg/ kg of aspirin ; B ) Gastric lesion & ulcer area (mm ) of rat stomachs after acute oral dosing of rats with aspirin ( 100 mg/ kg ) and its prodrug I- D1 - R1 (298 .85 mg/kg , which is a dose equimolar to 200 mg/ kg of aspirin ) . U . S . Patent Dec . 19, 2017 _ Sheet 6 0f12 US 9 , 844 , 599 B2

6A ) Gastric Ulcer Study of Naproxen and its prodrug 1 -D2 - R1 (NO -naproxen )

? ? .?? ? vehicle [ 0 . 5 % cic)

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??????? ?? 1 - p2 - Ri ( Monaproxen ) { 138 . 67 mg/ kgp. . . ) 68)

$ 580£88

GastricLesion&UlcerArea(mm) _ {Mearl£S.E,M

$ 39£20 * * *

...( kg,p Naproken{100 mg /kg - p. . .) / .67rmg p7131(118 * * * p < 0 . 001 ?versus Naproxen Figure 6 . A ) Images of rat stomachs showing gastric lesion and ulcer induction /sparing following acute oral administration of naproxen sodium ( 109 . 52 mg/ kg , which is equimolar to .100 _ mg/ kg dose of naproxen } and its promising prodrug I - D2- Ri ( i . e . , P7133 or N0 naprOxen ) at 138. 67 mg/ kg, which is adose equimolar to 100 rmg/ kg dose ofnaproxen in rats ; B ) Gastric lesion area (mm ) of rat stomachs after acute oral dosing of rats with naproxen SOdium ( 138 , 67 mg/ kg, which is a dose eqnmolar to 100mg/ kg dose of naproxen ) and its prodrug I - Dl - R1 ( 138 .67 mg/ kg, which is a dose equimmolar to 100mg/ kg ofnaproxen } . U . S . Patent Dec . 19 , 2017 Sheet 7 of 12 US 9 ,844 , 599 B2

SerumTXB2Levels(ng/ml) (MeanS.EM,n=6)

75 . 97 % 72 .59 % * * * * .. ..

Vehicle(1ml /kg) Aspirin (30 mg /kgP7097 ) (30 mg /kg eq .)

* * p < 0 .01 Vs . Vehicle

Figure 7 . In vivo inhibition of TXB2 ( i. e ., indicated by the reduction in serum TXB2 levels ) rats with aspirin (30 mg/ kg ) and its promising prodrug I -D1 - RI (i . e ., P7097 or NO -aspirin , 44 . 82 mg/ kg , which is equimolar to 30 mg/ kg dose of aspirin ) . U . S . Patent Dec. 19 , 2017 Sheet 8 of 12 US 9 ,844 ,599 B2

8A ) SGF

Aspirin(UM) Mean,(n=2)

0 20 40 60 80 100 120 Time (min ) Aspirin ( 100 PM ) + 1- D1 -R1 (100 PM ) 8B ) SGF 15000 (12348 ) ( 10406 )

Mean,(n=2) AUC(UM*h)Aspirin

Aspirin(100 MM ) 1-D1 - R1 (100 PM )

Figure 8 . Release of aspirin from prodrug I -D1 - R1 in Simulated Gastric Fluid (SGF ) ; Pooled data ( n = 2 ) ; A ) Line graph ; B ) Bar graph . U . S . Patent Dec . 19 , 2017 Sheet 9 of 12 US 9 , 844 ,599 B2

9A ) SIF

12504

UM)Aspirin( =2)Mean,(n

o 20 40 60 80 100 720 Time (min ) Aspirin ( 1 mM ) * 1- D1 - R1 ( 1 mm ) 9B ) SIF 150000 , ( 136861)

100000 (94862 ) Mean,(n=2) AUC(MM*h)Aspirin wwwwww 50000 wwwwwwwwwwwwwwwwwwwwwwww

Aspirin(1 mm ) 1-D1 - R1 (IMM )

Figure 9 . Stability of aspirin ( 1 mM )/ Release of aspirin from I -D1 - R1 ( 1 mM ) in Simulated Intestinal Fluid ( SIF ) ; Pooled data ( n = 2 ) ; A ) Line graph ; B ) Bar graph . U . S . Patent Dec. 19 , 2017 Sheet 10 of 12 US 9 , 844 , 599 B2

10A )

100 % Human Plasma

Aspirin(JM) Mean,(n=2)

0 20 40 60 80 100 120 Aspirin ( 100Time PM ) (min ) + 1- D1 - R1 ( 100 PM ) 10B ) 100 % Human Plasma 8000 ( 6803 ) 6000

Mean,(n=2) AUC(UM*h)Aspirin 2000 ( 352 )

Aspirin(100 PM ) 1-D1 -R1 (100 M)

Figure 10 . Degradation of aspirin ( 100 UM ) and release of aspirin from aspirin prodrug I- D1 R1 (NO -aspirin , 100 uM ) in human plasma; Pooled data ( n = 2 ) ; A ) Line graph ; B ) Bar graph . U . S . Patent _ Dec . 19, 2017 _ Sheet ll of12 US 9 , 844 ,599 B2

11A )

1100 % Human Plasma

_ ?? Salicyiate(M??) Mean,(n=2)

$_

_ " _ 20 _ e _ so _ 80 1 . 120 Time { mim ) Aspirin ( 1oo ?ul { ? l- p1 - 81 )100 ?? M ( 118 )

100 % Human Plasma

12000 (10576 )

9000 { 7313 ) Mean,{n=2) % Auc(uM*h)Salicylate

$

Aspirin)100 ??M (' I-D1R1 (100 |um )

Figure 11 . Release of salicylic acid from aspirin )100 ?? M ) and its prodrug I - Dl - R1 ) 100 ?? M( in human plagma ; Pooled data ( n = 2 ) ; A ) Line graph ; B ) Bar graph . U . S . Patent Dec . 19, 2017 Sheet 12 of 12 US 9 ,844 ,599 B2

12A )

140 .00 I -D3 -RI ($ 0 man Released Chlorambucil 120 .00 - Chlorambucil in SGF (504 .1 . 1 ) 100 .00 theyw 80 . 00 where Meirafrest(W)*3 60 . 00 + 0. 00

20 . 00 www.mamvuur

0 .00 * * ** poteter 0 . 09 0 . 15 0 .. 25 0 . 3 5 m20 .00 Time (Hr . ) 12B )

Time I - D3 -R1 Chlorambucil (mins ) I - D3- R1 Chlorambucil Chlorambucil Other Remaining Released ( % ) Remaining | metabolite ( % ) ( % ) ( % ) 92 . 12 7 .88 100 .00 0 . 00 20 .49 79 .51 100 , 00 0 . 00 10 13 . 84 86 . 16 100 .00 0 . 00 15 8 .59 91. 41 100 .00 0 . 00 30 0 . 00 100 . 00 100 . 00 0 . 00 60 0 .00 100 . 00 100 . 00 0 . 00 120 0 . 00 100 . 00 100 . 00 0 . 00 180 0 . 00 100 .00 100 . 00 0 . 00

Figure 12 . Stability of chlorambucil (50 uM ) / Release of chlorambucil from I- D3 - R1 (50 UM ) in Simulated Gastric Fluid ( SGF ) ; Pooled data ( n = 3 ) ; A ) Line graph ; B ) Table . US 9 ,844 ,599 B2 NITRIC OXIDE RELEASING PRODUGS OF 2000 ) . This problem has been solved by derivatisation of THERAPEUTIC AGENTS carboxylic acid group of NSAIDs into its ester and amide derivatives. RELATED APPLICATIONS Another common approach to minimize adverse effects of 5 the known drugs or therapeutic agents consists of attaching This application claims priority to PCT Application No. a carrier group to the therapeutic agents to alter their PCT/ IN2014 /000033 , filed Jan . 17 . 2014 and published on physicochemical properties and then subsequent enzymatic or non - enzymatic cleavage to release the active drug mol Jul. 24 , 2014 as International Publication No . WO 2014 / ecule ( therapeutic agent) . The therapeutic agent is linked 111957 , which itself claims priority to Indian Patent Appli 10 through a covalent linkage to specialized non - toxic protec cation No . 181/ MUM / 2013 , filed Jan . 21, 2013 , the disclo tive groups or carriers or promoieties in a transient manner sures and teachings of which are incorporated herein by to alter or eliminate undesirable properties associated with reference . the parent drug to produce a carrier- linked prodrug . Indeed , a more recent strategy for devising a gastric FIELD OF THE INVENTION 15 sparing NSAID involves chemically coupling a nitric oxide (NO ) releasing moiety to the parent NSAID . The approach The present invention relates to nitric oxide releasing and possibility of combining a few classes of drugs bearing prodrugs of known drugs or therapeutic agents which are different functional groups susceptible of derivatisation with represented herein as compounds of formula (I ) wherein the NO - donatingmoieties has been described by Menlo Bolla et drugs or therapeutic agents contain at least one carboxylic 20 al ., in Curr. Topics Med . Chem . 2005 : 5 : 707 - 720 . acid group . The invention also relates to processes for the Nitric oxide is one of the most important mediators of preparation of the nitric oxide releasing prodrugs ( the com mucosal defense , influencing factors such as mucus secre pounds of formula ( I ) ), pharmaceutical compositions con tion , mucosal blood flow , ulcer repair and the activity of a taining them and methods of using the prodrugs . variety of mucosal immunocytes (Med Inflammation , 1995 ; 25 4 : 397 - 405 ) . It has been reported to play a critical role in BACKGROUND OF THE INVENTION maintaining the integrity of the gastroduodenal mucosa and exerts many of the same effects as endogenous prostaglan Many drugs (therapeutic agents ) have undesirable prop dins (Drugs Fut 2001; 26 (5 ): 485 ). Several mechanisms are erties, for instance , low oral drug absorption , toxicity, poor considered to underlie its protective effect in the stomach patient compliance etc ., that may become pharmacological , 30 including vasodilation of local mucosal blood vessels , inhi pharmaceutical, or pharmacokinetic barriers in clinical drug bition of leukocyte adhesion and inhibition of caspase application . Among the various approaches to minimize the enzyme activity. The inactivation of caspase ( s ) appears to be undesirable drug properties, while retaining the desirable an important factor in the GI tolerance of nitric oxide therapeutic activity , the chemical approach using drug deri releasing NSAIDs (NO -NSAIDs ) ( J . E . Keeble and P . K . has been 35 Moore , British Journal of Pharmacology , 2002 ; 137 : 295 vatisation offers perhaps the highest flexibility and has been 33 310 ) . Nitric oxide can thus be used to devise a gastric demonstrated as an important means of improving drug sparing NSAID . Compounds that release nitric oxide in efficacy (Hyo -Kyung Han and Gordon L . Amidon AAPS small amounts over a prolonged period of time may be very PharmSci . 2000 ; 2 ( 1 ) ) . useful for the prevention of gastrointestinal injury associated The conventional approach that is adopted to minimize 40 with shock and with the use of drugs that have ulcerogenic the toxic side effects associated with the therapeutic agents effects (Muscara M . N .; Wallace J . L . American Journal of has been to derivatise one or more functional groups present Physiology , Gastrointestinal and liver physiology, 1999; 39 : in the drug molecule . The derivatives are then assessed for G1313 - 1316 ) . their therapeutic efficacy as well as toxicity . The carboxylic In recent years , several NO -releasing non - steroidal anti acid group is often present as an active functional group for 45 inflammatory drugs (NO -NSAIDs ) have been synthesized derivatisation in several therapeutic agents . Non - steroidal by an ester linkage formed through coupling of a NO anti- inflammatory drugs ( NSAIDs ) represent one of the best releasing chemical spacer group to the carboxylic acid class of drugs containing a carboxylic acid group as an moiety of a conventional NSAID . The use of various ali active functional group . NSAIDs are also the most com - phatic , aromatic or heterocyclic chemical spacers makes it monly used drugs to relieve pain , symptoms of arthritis and 50 possible to alter various physicochemical properties and soft tissue inflammation . Most patients with rheumatoid kinetics of nitric oxide release (Berguad et al . , Ann . N . Y . arthritis receive NSAIDs as a first - line treatment which is Acad . Sci. 1962: 360 - 371 ( 2002 ) ) . The first NO - asprin drug continued for prolonged periods. Although , NSAIDs pro NCX 4016 , which was synthesized relatively recently , con vide anti - inflammatory and analgesic effects , they also have sists of an aspirin molecule linked by an ester bond to a adverse effects on the upper gastrointestinal (GI ) tract . The 55 molecular spacer , which in turn , is linked to a nitro -oxy ester occurrence ofGI toxicity appears to be strictly correlated to group (Dig Liver Dis 2003 ; 35 ( suppl. 2 ) : 9 - 19) . A number of the mechanism of action of these drugs, namely the inhibi- NO -NSAID hybrid compounds , namely NO -naproxen tion of the enzyme cyclooxygenase . In fact, inhibition of (Naproxcinod ), NO - flurbiprofen (HCT 1026 ), NO - ibupro platelet cyclooxygenase, which causes prolonged bleeding fen , NO - diclofenac and NO - indomethacin have been dis time, and inhibition of cyclooxygenase in gastrointestinal 60 closed in the patent numbers EP 722434B1, U . S . Pat. No . mucosa, which results in a decreased synthesis of cytopro - 6 ,613 ,784 B1 and U .S . Pat . No . 7 ,220 ,749 B2 , respectively . tective gastric prostaglandins, represent the major cause of European Patent EP 722434B1 discloses nitrate esters of the serious gastrointestinal toxicity ( Symposium on “ New Anti - derivatives of propionic acid , 1 - ( p - chlorobenzoyl) - 5 inflammatory agents : NO -NSAIDs and COX - 2 inhibitors" methoxy - 2 -methyl - 3 - indolylacetic acid and 5 -benzoyl - 1, 2 part of the 11th international conference on “ Advances in 65 dihydro - 3H -pyrrolo [ 1 , 2 - a ]pyrrole - 1 - carboxylic acid having prostaglandin and leukotrine research : Basic science and anti - inflammatory and /or analgesic activity . U . S . Pat. No . new clinical applications” held in Florence ( Italy ) , Jun . 4 - 8 , 6 ,613 ,784 B1 discloses nitro derivatives of NSAIDs, for US 9 ,844 ,599 B2 instance, flurbiprofen , indomethacin , aspirin , naproxen and One such class of compounds can be represented by the diclofenac . U . S . Pat . No . 7 ,220 ,749 B2 discloses novel following generic or Markush structure (IA ) : nitrosated and / or nitrosylated derivatives of COX - 2 selec tive inhibitors . U . S . Patent Application Publication no . 20080293781A1 describes O -acyl salicylic acid derivatives 5 (IA ) bearing a NO donor moiety . U . S . Pat. No . 7 , 199 ,154 B2 discloses nitrosated or nitrosylated prodrugs for COX - 2 NO2 selective inhibitors that are useful for treating COX - 2 medi O ated diseases or conditions and which can be administered alone or in combination with low - dose aspirin . The com - 10 Wherein . pounds are effective in treating chronic COX - 2 mediated Dx represents a part of a drug or therapeutic agent diseases or conditions, reducing the risk of thrombotic containing at least one carboxylic acid group which forms a cardiovascular events and possibly renal side effects and at bio -cleavable ester bond with the specified linker and such the same time reduce the risk ofGI ulceration and bleeding. 15 drug or therapeutic agent is selected from the group con US Patent Application Publication no . 20060058363 A1 s isting of non - steroidal anti - inflammatory, analgesic and discloses nitric - oxide releasing prodrugs of celebrex and antipyretic drugs such as aspirin , diclofenac, naproxen and valdecoxib which are useful in the treatment of COX - 2 the like, COX -2 inhibitors, angiotensin -II receptor blockers mediated diseases. The compounds may be used as a com such as sartans ( i .e ., losartan , valsatan , candesartan , telmis bination therapy with low -dose aspirin to treat COX - 2 20 artan , eprosartan and olmesartan ), ACE inhibitors such as mediated diseases or conditions while simultaneously reduc captopril , enalapril and the like , beta ( B ) - blockers such as ing the risk of thrombotic cardiovascular events . timolol, atenolol and the like , HMG - CoA reductase inhibi Nitric oxide (NO ) also plays an important role in numer tors (cholesterol - reducing agents ) such as statins ( i . e. , fluv ous other physiological and pathophysiological conditions, astatin , pravastatin , cerivastatin , atorvastatin and rosuvasta e . g . blood pressure regulation , inflammation , infection and 25 tin ) , antiulcerative agents such as misoprostol acid and so on the onset and progression of malignantnant and cardiovascular amongam others ; diseases (Lirk , P ., Hoffmann , G ., and Rieder , J . Curr . Drug Targets Inflamm . Allergy 2002 ; 1 : 89 - 108 ) . Though delivery Xz independently represents at each occurrence a linear or of supplementary NO in the form of NO - donor drugs has branched alkylene C , -C20 preferably alkylene C -C10 , yet long been an attractive therapeutic strategy ( Ian L Megson , 30 preferably alkylene C , - C6 , yet preferably alkylene C2 -C10 , David J Webb , Expert Opin . Investing. Drugs, 2002 ; 11 ( 5 ) : substituted alkylene C , - C20 , substituted alkylene C -C103 587 - 601) , in recent years , with the advent of NO -NSAID cycloalkylene C3 -C7 , cycloalkylene C3 -C7 , optionally sub approach and because of the beneficial biochemical and stituted cycloalkylene C3- C , or C5- C7 , or [ C (R “ )( R ) ] m , pharmacological properties of nitric oxide, the strategy of Wherein , linking NO - releasing moieties has been extended to a wide 35 m = 1 - 20 , preferably 1 - 10 , yet preferably 1 - 0 or 2 - 10 or array of therapeutic agents selected from cardiovascular drugs, for instance, Angiotensin converting enzyme ( ACE ) R™ and Rº at each occurrence are independently a hydro inhibitors, calcium antagonists and beta -blockers , antitumor gen , substituted or unsubstituted straight or branched alkyl agents , antihistamines, glucocorticoids, etc . The aim of this C2 -C20 , preferably alkyl C1- C10 , or yet preferably alkyl strategy is to synthesize prodrugs that retain the pharmaco - 40 C1 -Coor logical activity of the parent drug molecule coupled with the Ra and R taken together with the carbon atom to which benefits of the biological actions of NO in reducing the they are attached form a cycloalkyl group , and so on among adverse effects of the parent drug molecule . others ; U . S . Pat. Nos . 6 ,610 , 676 and 7 ,524 , 836 B2 disclose The above Markush formula (IA ) is deduced from the nitrate esters and nitrooxy derivatives of steroidal com - 45 following 20 relevant patent applications . pounds having anti- inflammatory , immunodepressive and 1 . WO2007054451 (Nicox S . A ., Fr. ) . angiostatic activity or gastrointestinal activity . 2 . CN101053662 ( Jiangsu Wuzhong Suyao Drugs Develop PCT Application Publication WO2007099548A1 dis - ment Co ., Ltd ., Peop . Rep . China ) . closes 11ß -hydroxyandrosta -4 - 3 - one compounds which 3 . WO2005070868 (Merck Frosst Canada & Co ., Can .) . possess useful anti - inflammatory activity whilst having 50 4 . WO2005030224 (Nicox S . A . , Fr. ) . insignificant or no noteworthy side -effects at efficacious 5 . WO2005011646 ; Family : AU2004260830 (Nicox S . A ., doses . PCT Application Publication . WO2008095809A1 Fr. ) . discloses derivatives of known corticosteroids, containing a 6 . WO2004035042 , Family : AU2003269774 (Astrazeneca NO - releasing moiety which are useful in the treatment of UK Limited , UK ). illnesses wherein the known corticosteroid , parent or pre - 55 7 . WO2004004648 , Family : CA2491127 (Nitromed , Inc ., cursor steroid , is generally applied , with increased benefit in USA ) . terms of pharmacological profile and fewer or milder side 8 . WO2003094923 , Family : AU2003236636 ( Scara effects than those of the parent corticosteroids. muzzino , Giovanni) , WO2003084550 , Family : The NO -releasing derivatives and prodrugs of various AU2003224002 ( Nicox S . A ., Fr. ) . therapeutic agents known in the art are in different phases of 60 9 . EP1219306 , Family : AU2002219225 ( Nicox S . A . , Fr. ) . clinical development and there are reports suggesting that a 10 . W09821193 , Family : CA2272063 (Nicox S . A ., Fr. ; Del few of them have been suspended because of some problems Soldato , Piero ) . ( see press reports on naproxcinod and NCX4016 at www .ni - 11 . WO9809948 , Family : EP931065 (Nicox S . A . , Fr. ) . cox . com ) . Therefore , there is a clear unmet medical need for 12 . W09716405 , Family : EP871606 (Nicox S . A ., Fr. ) . new , alternative and better NO -releasing nitrate ester prod - 65 13 . W09530641, Family : EP759899 (Nicox Ltd ., Ire .) . rug compounds which can exhibit improved therapeutic 14. WO2007088123 , Family : AU2007211508 (Nicox S . A ., properties . Fr. ) . US 9 ,844 ,599 B2 15 . CN1966484 (Beijing Meibeita Pharmaceutical Research Consequently , a vast majority of ester prodrugs of aspirin Co . , Ltd ., Peop . Rep . China ) . turn out be prodrugs of salicylic acid . However, in case of 16 . WO2004020384 , Family : EP1532098 (Nicox S . A . , Fr. ). aspirin , the promising NO - aspirin prodrug I -D1 - R1 ( i. e . 17 . WO2001010814 , Family : EP1200386 (Nicox S . A . , Fr. ). Dx = D1= aspirin ; Ry = R1 = CH3) of the present invention was 18 . WO2009000592 , Family : EP2164484 (Nicox S . A ., Fr. ) . 5 seen to act as a true prodrug of aspirin , when tested for its 19 . WO2004105754 , Family : US7166638 (Nicox S . A . , Fr. ) . capability to release aspirin in Simulated Gastric Fluid 20 . WO9858910 , Family : EP989972 (Nicox S . A ., Fr. ) . ( SGF ) ( FIG . 8 ) and Simulated Intestinal Fluid (SIF ) ( FIG . We now report a small set of compounds of formula (1 ) 9 ) . The prodrug I- D1 - R1 was evaluated at a concentration of which possesses surprising and unexpected properties when either 100 uM or 1 mM in SGF (aspirin was co -evaluated as compared with compounds of formula (IA ). 10 a positive control under the same experimental conditions, at equimolar doses) and has shown dose dependent decrease / increase in the amount of aspirin released . In SIF also , the prodrug I -D1 - R1 released significant amount of aspirin at 1 0 H Ry mM concentration . However , although the aspirin release increased in a dose - dependent manner, it was significantly Dx ONO less than that of aspirin standard at equimolar doses . In SIF , with its pH in the range of ~ 6 - 7 , a certain percentage of the Wherein , prodrug preferentially underwent de -acetylation to give sali Dx is a part of a drug/ therapeutic agent containing at least 20 cyliccyli acid intermediate which further degraded to salicylic acid . one carboxylic acid group [ i. e ., DxCO2H ] which is cova Interestingly , the behaviour of NO -aspirin (i . e . lently bonded to the specified linker “ C ( H ) ( Ry ) ” via a Dx = D1= aspirin ) prodrugs of formula ( I) was seen to be bio -cleavable ester linkage; significantly different from the analogous compounds of Ry is an alkyl C1- C or cycloalkyl C3- C7 ; preferably alkyl formula (IA ) [ ( i . e . , with the same molecular formula and C1- C4 ; yet preferably alkyl C1- C2; yetmost preferably Ry is 25 molecular weight but with different structural features; i . e . , methyl ( i . e . , CH3) ; structures 1 -D1 - R1 and II -D1 - X2 , respectively ) . When these ONO2 ( a nitrooxy ) group is covalently bonded to the other two compounds were incubated simultaneously in SGF, it side of the linker ; was observed that only the compound of formula ( I ) , i. e . , and all its geometrical and stereoisomeric forms and I -D1 - R1 , of the present invention , released quantitative pharmaceutically acceptable salts thereof . amounts of the parent drug aspirin whereas the compound of The compounds of the present invention represented by formula ( IA ) i . e ., II -D1 - X2 , quickly decomposed into an formula ( I ) are generically covered within the scope of some unknown metabolite , without releasing even traces of aspi of the patents or patent applications listed above. rin . Additionally, another analogous NO -aspirin compound Obviously , the Markush formula ( IA ), with so many 25 NCX -4016 of formula (IA ) that had reached phase II clinical variables , would encompass several thousand or even mil - trials ( structure shown below ) remained intact (no release of lions of possible compounds including the compounds of parent drug , aspirin ) when incubated in SGF under identical formula (I ) of this invention . However, none of the above conditions ( Table 1 ). mentioned prior art documents specifically disclosed or claimed any of the possible compounds of this invention that 40 are represented specifically by the formula (I ) . I -D1 - R1 A characteristic and unique structural feature of the spe cific set of compounds of formula ( I ) of the invention ( i . e . , representing a species) when compared to those of the H2CO CH3 compounds of formula IA ( i . e . , representing a genus ) is the 45 presence of a unique " acyl -acetal ” type linkage represented DNO, by “ _ C ( O ) - 0 C ( H ) (Ry ) - 0 — ” group , which is a “ hybrid ” form of an ester and an acetal group . This charac teristic and unique structural feature possibly imparts hith erto undisclosed properties to the compounds containing this 50 MF : C11HUNO “ acyl- acetal ” type linkage which are essentially the com MW : 269 .21 pounds of this invention specifically represented by the formula (I ) . Some of the characteristic properties exhibited by these unique set of compounds include : 55 II- D1 - X2 1 . The compounds of formula (I ) are the only kind of nitric oxide releasing ester prodrugs of carboxyl -containing drugs that encompass the unique “ acyl - acetal” type struc HCHzC? tural feature . 2 . Upon incubation in simulated gastric and /or intestinal 60 fluid / s , the compounds of formula ( 1 ) readily released significant amounts of parent drugs ( including aspirin ! ) . It is well known to the people skilled in the art that it has been a very difficult task to design a true ester prodrug of [ Xz = X2 = CH2CH2] aspirin due to the presence of a very labile acetyl group 65 MF: C11H11NO , which undergoes preferential hydrolysis by plasma MW : 269. 21 esterases . US 9, 844 ,599 B2

-continued -continued

II - D1- X1 5 II - D2 - X2

HzCO E. ONO2 -NO2 10 Me0 [X2 = (CH2 ) 2 ] [ Xz = X1 = m - C6H4CH2 ] Chemical Formula : C16H17N06 MF: C16H13NO7 Molecular Weight: 319 . 31 MW : 331. 28 15

JianTABLE 1 . com Stability study of NO - aspirin prodrugs in SGF I - D1 -R1 II - D1 - X2 II- D1 - X1 [NCX - 4016 ] (Ry = R1 = CHz) Xz = X2 = CH . CH , Xz = X1 = m - C6H _CH , ] Time % of Prodrug % of Aspirin % of Prodrug % of Aspirin % of Prodrug % of Aspirin Point remaining Released remaining Released remaining Released (min ) (UM ) (UM ) (UM ) (UM ) ( UM ) (UM ) 0 The prodrug Aspirin 100 . 00 Aspirin 18 underwent release was 100 .00 release was quick not observed 100 . 00 not observed longen decomposition 100 . 00 100 into an 100 .00 120 100 unknown 100 . 00 metabolite t12 < 15 min ~ 1 . 5 min

In case of naproxen series also , the behaviour of NO TABLE 2 naproxen ( i. e . Dx = D2= naproxen ) prodrugs of formula ( 1 ) was seen to be significantly different from the analogous 40 Stability of prodrugs I- D2- R1 and II- D2 - X2 in SGF compounds of formula (IA ) ( i . e . , with the same molecular formula and molecular weight but with different structural I- D2 -R1 (Ry = R1 = CH3) II -D2 -X2 [Xz = X2 = (CH2 ) 2 ] features ; See structures I -D2 - R1 and II -D2 - X2, shown below ); when incubated simultaneously in SGF , itI was 45 TimeTime I - D2 - R1 Naproxen II -D2 - X2 Naproxen observed that only the compound of formula (I ) of the (mins ) Remaining ( % ) Released ( % ) Remaining ( % ) Released ( % ) present invention i. e ., I -D2 - R1 released quantitative amounts of the parent drug , naproxen whereas the com 100 .00 0 . 00 100 . 00 0 .00 pound of formula (IA ) i. e . , II- D2 -X2 remained intact (no 84 .68 15 .32 99 .68 0 . 32 50 release of parent drug naproxen ) under identical conditions 74 . 58 25 . 42 99. 79 0 .21 ( Table 2 ). 8Woüöno 64 .58 35 .42 99. 68 0 . 32 32 . 79 67 . 21 99 . 75 0 .25 0 . 00 100 .00 99. 67 0 . 33 55 120120 0 . 00 100 .00 99. 39 0 .61 180 0 .00 100 . 00 99 . 19 0 . 81 I - D2 -R1 t12 20 - 25 min NA

60 se NO2 Even the higher homologue pairs of naproxen prodrugs of CH3 formula ( I ) and formula (IA ) i. e ., I -D2 - R2 vs II - D2- X3 and Me01 I - D2- R3 vs II - D2 -X4 behaved in a similar fashion , when Chemical Formula : C16H17N06 65 incubated simultaneously in SGF. Thus only compounds of Molecular Weight: 319. 31 formula (I ) i. e. , I- D2 - R2 and I- D2 -R3 released naproxen ( Tables 3 and 4 , respectively ). US 9, 844 ,599 B2 a 10 TABLE 4 I -D2 - R2 Stability of prodrugs I - D2- R3 and II- D2 - X4 in SGF

. I - D2 - R3 II - D2- X4 5 ( Ry = R3 = CH CH . CH ) [Xz = X4 = (CH )AL " NO I - D2 - R3 Naproxen II - D2 - X4 Naproxen Time Remaining Remaining Remaining Remaining Meo -CH3 (mins ) ( % ) ( % ) ( % ) ( % ) Chemical Formula : C17H19NO6 10 100 0 .00 100 . 00 0 . 00 Molecular Weight: 333 .34 96 . 35 3 .65 100 .00 0 . 00 ou 93. 61 6 . 39 100 . 00 0 . 00 15 83. 21 16 . 79 100 . 00 0 .00 30 82. 73 17 . 27 100 . 00 0 .00 60 75 . 48 24 . 52 100 . 00 0 . 00 15 120 57. 55 42 . 45 100 . 00 0 . 00 II - D2 - X3 180 39. 00 61 .00 100 .00 0 .00 t1/ 2 ~ 2 . 5 h NA

LONO2 30 A still higher homologue of naproxen prodrug of formula 20 ( I) , i. e. , I- D2 - R4 , also released appreciable amounts of the parent drug naproxen when incubated in SGF, as shown Meo below ( Table 5 ). [X3 = (CH2 ) 3 ] Chemical Formula : C17H19N06 25 Molecular Weight : 333 .34 I - D2 - R4

TABLE 3 30 NO2 Stability of prodrugs I- D2- R2 and II -D2 - X3 in SGF I -D2 -R1 (Ry = R2 = CH2CH ) II- D2 -X3 [Xz = X3 = (CH ,) al Me01 CH3 Chemical Formula : C19H23N06 Time I- D2 - R2 Naproxen II - D2 - X3 Naproxen Molecular Weight: 361 .39 (mins ) Remaining ( % ) Released ( % ) Remaining ( % ) Released ( % ) 35 100 0 . 00 100 .00 0 . 00 94 . 33 5 . 67 100 . 00 0 . 00 10 90 . 43 9 . 57 100 . 00 0 .00 TABLE 5 15 74 . 27 25 . 73 100 . 00 0 . 00 Stability of prodrug I- D2 - R4 in SGF 30 62 . 15 37. 85 100 . 00 0 . 00 40 60 51 .01 48. 99 100 . 00 0 .00 120 39 .08 60 . 92 100 . 00 0 . 00 I- D2 - R4 ( Ry = R4 = CH CH , CH , CH ) 180 6 .77 93. 23 100 .00 0 .00 - 1 h NA Time I -D2 - R4 Naproxen t112 (mins ) Remaining ( % ) Released ( % ) 45 100 0 . 00 97 . 74 2 . 26 96 . 18 3 . 82 I -D2 - R3 87 . 41 12 . 59 85Sn 90 . 53 9 .47 88. 87 11. 13 50 120 79 . 97 20 . 03 NO2 180 71. 04 28 . 96 mu t1/ 2 > 3 h CH3 Me0 From the above data , it is obvious that the compounds Chemical Formula : C18H21N06 55 ( prodrugs of naproxen ) of formula ( 1 ) release decreasing Molecular Weight: 347. 36 amounts of parent drug naproxen with increasing alkyl chain II - D2 - X4 length of Ry (probably due to solubility issues associated CH3 with increased hydrophobicity of longer alkyl chains) . Thus , .III the half - lives (t12 ) of prodrugs of naproxen of formula ( I) ONOONO2 . 60 follow the pattern : I -D2 - R1 ( +12 = ~ 20 - 25 min ) < I- D2 -R2 ( t1/ 2 = ~ 1 h ) < I -D2 - R3 (t1 / 2 = ~ 2 . 5 h ) < I -D2 -R4 (t1 / 2 = > 3 h ) . Me0 Similarly , I- D3 - R1 , which is the nitric oxide releasing [X4 = ( CH2) 4 ] prodrug of chlorambucil of formula ( I) ( i. e ., Chemical Formula : C18H21NO . 65 Dx = D3 = chlorambucil , Ry= R1 = CH3) also released its parent Molecular Weight: 347. 36 drug chlorambucil quantitatively when incubated in SGF as shown below (See Table 6 and FIG . 12 ) . US 9, 844 ,599 B2 12 -continued I -D3 -R1 Step 3 : . AgNO3 NO2 HO - BIBr ACN HortHO O 5 HO — X — Br HO — X — ONO2 "CH3 Step 4 :

XzNO2 TEA 10 Da + HOO DCM HO — X — ONO2 manierTABLE 6 Dx - C ( = O ) CI Stability of prodrug I - D3 -R1 in SGF Xz NO2 I - D3 -R1 (Ry = R1 = C 15 Dý 0 Time I- D3 - R1 Chlorambucil (mins ) Remaining ( % ) Released ( % ) (IA ) 92 . 12 7 . 88 20 . 49 79 .51 20 Step 1: Conversion of the drug or therapeutic agent 13 . 84 86 . 16 containing carboxylic acid group (Dx - CO , H ) to its active nou 8 . 59 91 . 41 acid chloride Dx - C ( O )Cl by reacting with thionyl chloride 30 0 . 00 100 . 00 or oxalyl chloride in presence of catalytic amount of DMF; 60 0 . 00 100 .00 Step 2 : Conversion of diol HO -Xz -OH for example 120 0 . 00 100 . 00 1 , 2 - Ethanediol or 1 , 3 - Propanediol or 1 , 4 - Butanediol 180 0 . 00 100 . 00 5 (wherein Xz is as defined above ) , into its mono bromide t12 < 5 min derivative HOXz- Br, by known methods for example by treating with carbon tetrabromide and triphenylphosphine in Interestingly , the chlorambucil prodrug I- D3 - R1 , which is a solvent such as DCM ; the lowest carbon homologue among the chlorambucil pro - Step 3 : Conversion ofmonobromide HO - Xz -Br from Step drugs of formula ( I ) , decomposed in SGF to give 100 % of 30 3 into the corresponding mononitrate HO - Xz -ONO , by the parent drug chlorambucil , with a half - life of less than 5 treating with silver nitrate in acetonitrile ; minutes ( Table 6 ). Step 4 : Reaction of acid chloride from Step 1 with the mononitrate from Step 3 in the presence of a suitable base 3 . The compounds of formula ( I) exhibited nearly similar or such as triethylamine in a suitable solvent such as DCM to superior oral bioavailability and efficacy as compared to, 35 yield the compound of formula (IA ). those of respective parent drugs in rats (See FIGS. 1 , 2 , 3 In contrary , the process for making the compounds of and Table 7 ) . formula ( I ) involves significantly different steps as shown in 4 . Although the compounds of formula (I ) at equimolar Schemes 1 and 2 . doses exhibited nearly similar or superior oral bioavail - For clarity , a plausible mechanism for the formation of the ability and efficacy as compared to those of their respec - 40 compounds of formula (I ) is shown below : tive parent drugs, they did not cause any significant drug - induced gastric lesions and / or bleeding. However , their respective parent drugs at equimolar doses caused Chart 1B . A Plausible mechanism for the formation of composition of the significant drug - induced gastric lesions and/ or bleeding compounds of formula (I ) (See FIGS. 5 and 6 ) . 45 Ry 5 . The process for making the compounds of formula ( 1) ZnCl2 Dx ci DCM differs significantly when compared to the reported pro Dý ZnZn + H1 cesses for making the compounds of formula ( IA ) . CIC1 CI For example , the most frequently used process formaking Dx - C ( = O )CI Ry – CHO the compounds of formula ( IA ) involves the steps , as shown 50 OH Ry in the Chart 1A : AgNO3 Dx o 1 ci ACN Chart 1A : The most usual process for the synthesis of compounds of NO3 formula ( IA ) 55 Dx — Ry - ci Step 1 : 0 h Ry IN V NO2 (COCI ) 2 /DMF Dx Oo o DÝ OH DCM Dx ci Lo CoconutDCM 1 - Dx — Ry Dx Dx - C ( = O ) CI (I ) Step 2: Wherein , Dx = drug or part of the drug containing at least one carboxylic acid group ; Xz CBr4 , TPP , DCM Dx — C ( = O )Cl can be freshly prepared from Dx — CO2H by using a known HO OH HO Br method ; and 65 Ry - Alkyl C1- C6 . HO — X her— OH someone HOor — X — Br US 9 ,844 ,599 B2 13 14 It would be understood by a person skilled in the art that FIG . 10 . Degradation of aspirin (100 uM ) and release of in the compounds of formula ( I ), the “ CO ” group adjacent aspirin from aspirin prodrug I -D1 - R1 (NO -aspirin , 100 uM ) to Dx is derived from the carboxyl group of the drug (i .e . , in human plasma ; Pooled data ( n = 2 ); A ) Line graph ; B ) Bar Dx - CO , H ) as shown in chart 1B . graph . The above mentioned characteristic properties of the FIG . 11. Release of salicylic acid from aspirin ( 100 UM ) unique compounds of the present invention represented and its prodrug 1 -D1 - R1 ( 100 uM ) in human plasma ; Pooled specifically by the formula (I ) [i .e . , representing a specific data (n = 2 ); A ) Line graph ; B ) Bar graph . species comprising the compounds of formula (1 ) ] are nei- FIG . 12 . Stability of chlorambucil (50 uM )/ Release of ther disclosed specifically in the prior art (i . e . , representing 10 chlorambucil from I -D3 -R1 (50 uM ) in Simulated Gastric the whole genus comprising the compounds of formula (1A ) ] Fluid (SGF ) ; Pooled data (n = 3 ); A ) Line graph ; B ) Table . nor obvious to those skilled in the art to which this invention relates . The unique structural features and characteristic properties of the compounds of formula ( I ) therefore con DETAILED DESCRIPTION OF THE stitute or impart both “ novelty and inventive features ” to 15 INVENTION these potentially useful compounds. The present invention encompasses compounds of for mula ( 1 ) , as described herein , which are nitric oxide releas BRIEF DESCRIPTION OF DRAWINGS ing prodrugs of known carboxyl- containing drugs or thera 20 peutic agents useful in the treatment of diseases or disorders FIG . 1. Oral absorption profile of aspirin and its prodrugs that are characteristic of the drugs from which the prodrugs 1 -D1 -R1 ( 1. e ., P7097 ), 1 -D1 - R2 ( i. e ., P7244 ) and 1 -D1 - R3 of the present invention are derived . (i . e . , P7245 ) in SD Rats ; A ) Line graph ; B ) Bar graph . FIG . 2 . Oral Absorption profile of aspirin and its prodrugarug 25 I -D1 - R1 in Wistar Rats; A ) Line graph; B ) Bar graph . FIG . 3 . Oral absorption profile of naproxen and its pro ? H Ry drugs I -D2 -R1 ( i. e . , P7133 ) , I -D2 -R2 ( i. e . , P7135 ) , I- D2 - R3 NO, ( i. e ., P7134 ) and I - D2- R4 ( i. e ., P7132 ) in SD Rats ; A ) Line Dx OO o graph ; B ) Bar graph . 30 FIG . 4 . Plasma NOx ( nitrate /nitrite ) levels following oral In general , the present invention provides prodrugs of administration of prodrugs I- D1 - R1 and I- D2 - R1 in rats . known drugs or therapeutic agents represented herein by the FIG . 5 . A ) Images of rat stomachs showing gastric lesion compounds of formula (I ) which primarily constitutes the and ulcer induction / sparing following acute oral adminis - 35 following elements: tration of aspirin ( 100 mg/ kg ) and its promising prodrug ( a ) a drug or a therapeutic agent containing at least one I -D1 - R1 ( i. e ., P7097 or NO - aspirin ) at 298 . 85 mg/ kg , which carboxylic acid group [i . e ., DxCO2H ] that is covalently is a dose equimolar to 200 mg/ kg of aspirin ; B ) Gastric bonded to one side of the linker ; lesion & ulcer area (mm² ) of rat stomachs after acute oral ( b) a linker [i . e ., C ( H )( Ry ) ]; and dosing of rats with aspirin ( 100 mg/kg ) and its prodrug 40 ( c ) a nitrooxy (ONO2 ) group covalently bonded to the I - D1- R1 (298 .85 mg/ kg , which is a dose equimolar to 200 other side of the linker; mg/ kg of aspirin ). The strategy for providing the prodrugs represented FIG . 6 . A ) Images of rat stomachs showing gastric lesion herein by the compounds of formula ( I ) is applicable to any and ulcer induction /sparing following acute oral adminis - u . drug or therapeutic agent which possesses a carboxylic acid tration of naproxen sodium ( 109 .52 mg/ kg , which is functional group capable of forming a covalent ester bond to equimolar to 100 mg/kg dose of naproxen ) and its promising a specified linker. The linker is a bi- functional moiety having prodrug I -D2 -R1 ( i . e ., P7133 or NO -naproxen ) at 138 .67 the desired covalent binding properties. mg/kg , which is a dose equimolar to 100 mg/ kg dose of The prodrugs, i .e ., the compounds of formula ( I) of the naproxen in rats ; B ) Gastric lesion area (mm² ) of rat 50 present invention , would undergo either chemical or enzy stomachs after acute oral dosing of rats with naproxen matic cleavage in a manner such that the parent drugs and sodium (138 .67 mg/ kg , which is a dose equimolar to 100 effective amounts of nitric oxide are released in vivo . Also , mg/ kg dose of naproxen ) and its prodrug I -D1 - R1 ( 138 .67 the prodrugs of the present invention [ i . e . the compounds of mg/ kg , which is a dose equimolar to 100 mg/ kg of formula ( 1 ) ] are expected to be safe to administer and seem 55 to have the potential to exhibit comparable or superior oral naproxen ). 55 bioavailability to that of the parent drug molecule . FIG . 7 . In vivo inhibition of TXB2 (i . e. , indicated by the Although the compounds of formula ( I) of the present reduction in serum TXB2 levels ) after oral dosing of rats invention are derived from the drugs or therapeutic agents with aspirin (30 mg/ kg ) and its promising prodrug I -D1 -R1 containing at least one carboxylic acid group , many such ( i. e ., P7097 or NO - aspirin , 44 . 82 mg/ kg , which is equimolar 60 drugs or therapeutic agents may contain other reactive to 30 mg/ kg dose of aspirin ) . functional groups such as an amino , additional carboxyl, FIG . 8 . Release of aspirin from prodrug I -D1 - R1 in hydroxyl ( including phenolic ) , sulfhydryl, phosphate , alde Simulated Gastric Fluid ( SGF) ; Pooled data ( n = 2 ) ; A ) Line hyde and keto ( in the form of their derivatives such as graph ; B ) Bar graph . oxime , hydrazone , semicarbazone and the like ) groups or a FIG . 9 . Stability of aspirin (1 mM )/ Release of aspirin 65 mixture of one or more types of these functional groups. As from I -D1 - R1 ( 1 mM ) in Simulated Intestinal Fluid (SIF ) ; a result , the compounds of formula ( I ) could also be repre Pooled data ( n = 2 ) ; A ) Line graph ; B ) Bar graph . sented by the following alternative formula I - a : US 9 ,844 ,599 B2 15 16 PPG represents a bio - cleavable phosphate protecting ( I- a ) group such as 2 - ( S -acetylthio ) ethyl ( SATE ) , 3 -pivaloyloxy . H Ry 1 , 3 -dihydroxypropyl derivative , dithiodiethanol derivative , Vu NO2 4 -acyloxybenzyl phosphate mono or diester derivatives and ( HX ) AnDx, 0 5 the like ; and the remaining elements of the formula ( I) ( or I- a or Wherein , 1 -b ) are same as defined above; (HX ) . -Dx - C40) O represents a drug or therapeutic A good example of one such drug is aspirin , i .e ., o -acetyl agent containing at least one carboxylic acid group , which is salicylic acid , wherein the anti - inflammatory drug salicylic covalently bonded to the specified linker “ COH ) (Ry ) ” via a acid has , in addition to the required one carboxylic acid bio -cleavable ester linkage; where group , one additional reactive phenolic hydroxyl group , X independently at each occurrence represents 0 (i . e ., which is protected by the bio -cleavable acetyl group . corresponds to a primary , secondary , tertiary or phenolic Unless otherwise indicated , the following definitions are hydroxyl group ), S ( i . e . , corresponds to a primary , second - 15 set forth to illustrate and define the meaning and scope of ary , tertiary or thiophenolic sulfhydryl group ), carboxylate various terms used to describe the invention herein and the ( i. e ., CO2 ) , amino group (i . e . , NH or N , which represent claims. These definitions should not be interpreted in the primary or secondary amino groups , respectively ), a phos literal sense as they are not general definitions and are phate ?i. e ., P ( = O ) ( O ) ) ), a carbonyl group (i .e ., an aldehyde relevant only for this application . or keto group in the form of their bio -cleavable derivatives 20 As used herein , the term “ prodrug or prodrugs ” refers / such as an oxime, hydrazone, semicarbazone and the like ) or refer to a compound /compounds which upon administration a mix of one or more types of these functional groups; to a subject in need thereof undergoes cleavage in vivo either n represents 0 ( zero ) or 1 - 20 , preferably 0 ( zero ) or 1 - 10 , by enzymatic or chemical processes to release the parent yet preferably 0 ( zero ) or 1 -5 , yet most preferably 0 ( zero ) drug from which the prodrug is derived . or 1- 2 ; As used herein , the terms " drug” or “ drugs” or “ thera Ry is an alkyl C , C . or cycloalkyl C . C i preferably alkyl peutic agents" or " drug molecules " or " parent drug ” or " parent drug molecules ” , which are represented by the C1- C4 ; yet preferably alkyl C Cz; yet most preferably alkyl symbols “ Dx” or “ Dx - C ( O ) O ” or “ (HX ), , - Dx - C ( O ) O " Ci (i . e . , CHz) ; or “ (HX ) n - Dx- C ( O ) O ” or “ ( PG - X ). - Dx - C ( = O ) O ” ONO2 ( i. e ., nitrooxy) group is covalently bonded4 toto methe 2030 [where w ? PG represent an appropriate bio -cleavable protect other side of the linker ; ing group for an amino ( " PG ) or a hydroxyl (" PG ) or a and in all its geometrical and stereoisomeric forms and sulfhydryl ( ?PG ) or a carboxyl ( PG ) or a phosphate (FPG ) also pharmaceutically acceptable salts thereof; group ] are used interchangeably when n represents 0 ( zero ) . Also encompassed within the scope of the invention The term “ drug ” or “ therapeutic agent ” as used herein refers represented by the formula (I ) are the compounds of the 35 to any compound , substance, medicament or active ingre invention , wherein , the drug or therapeutic agent contains, in dient having a therapeutic or pharmacological effect , and addition to the required one carboxylic acid functional which is suitable for administration to a mammal, e . g . , a group , one or more other reactive functional groups such as human , more particularly , in the context of the present an amino , a hydroxyl ( including phenolic and hydroxyl invention , all the known drugs or therapeutic agents con group of oxime derivative of a carbonyl group of an alde -. an40 taining at least one carboxylic acid functional group that is hyde or keto group ), a sulfhydryl, a phosphate or additional capable of forming a covalent biocleavable ester linkage carboxyl group ( s ) , or a mixture of one or more types of the with a specified linker. The term “ drug ” or “ therapeutic said functional groups and these additional functional agent” as used herein also encompasses within its scope the groups have to be specifically protected , if necessary , by " investigational drug (s )” or “ investigational agent (s ) ” which appropriate bio - cleavable protecting groups ( PGs) ; Conse 45 refer to any new drug or agent currently under clinical quently , the compounds of formula ( I ) could also be repre investigation , particularly those investigational drugs or sented by the following alternative formula I -b : agents that contain at least one carboxylic acid group that is capable of forming a covalent biocleavable ester linkage with a linker, which may later be established as therapeuti 110 ) 50 cally active agent by the regulatory bodies of different 0 H Ry countries . As stated above , such drugs or therapeutic agents (ZPG - n - DX may also contain , in addition to the required one carboxylic Dx 0 acid group , other reactive functional groups such as an amino , additional carboxyl, hydroxyl ( including phenolic ), Wherein , 55 sulfhydryl, phosphate , aldehyde and keto (or their deriva X -2PG represents O - " PG , S - SPG , C O ) O - PG , NH tives such oxime, hydrazone , semicarbazone and the like ) " PG , N - " PG or [ P ( = O ) ( O -PPG )2 ] , where groups. It is of common understanding that such additional " PG represents a bio - cleavable hydroxyl protecting group reactive functional groups need to be protected , if it is such as acetyl group and the like ; necessary, with appropriate protecting groups and again * PG represents a bio -cleavable sulfhydryl protecting 60 those protecting groups may need to be removed at appro group such as acetyl group , disulfide bond and the like ; priate stages of the processes for the synthesis of compounds PG represents a bio - cleavable carboxyl protecting group of formula ( I) . However , it is preferable to use such pro such as lower ( alkyl C1- C . ) alkyl esters and the like; tecting groups that can be cleaved under physiological " PG represents a bio -cleavable amino protecting group conditions so that we can avoid the process of removal of such as acetyl, ethoxycarbonyl, 2 - acetylthioethoxycarbonyl 65 those protecting groups from the compounds of the inven or 2 - ( 2 - aminoethyl) dithioethoxy -carbonyl group and the tion represented by the formula ( I) . Thus, the compounds for like ; formula (I ) containing additional reactive functional groups, US 9 ,844 ,599 B2 17 18 which are protected by appropriate bio -cleavable protecting carbonyl) and amides such as acetyl, methoxyacetyl, etc . groups , are within the scope of this invention . The procedures for the formation of the above mentioned As used herein , the term " linker ” or “ linkers ” or “ bio bio - cleavable amino protecting groups are based on the cleavable linkers” or " spacer” or spacers ” refers/ refer to a known methods and their relevant references as cited in T . chemical moiety /moieties , which forms/ form a covalent 5 W . Greene , “ Protective Groups in Organic Synthesis ” , Third ester linkage with the reactive carboxylate group of the drug Edition . 1999 . John Wiley and Sons . New York , are incor or therapeutic agent to obtain a prodrug of the drug . This porated herein as a reference. Additional examples of bio linker may be cleaved from the prodrug by chemical means , by enzymatic means , or by both the means. The linker may cleavable amino protecting groups are shown in Chart 2 . be pharmacologically inert or may itself provide added 10 As used herein , the term “ bio - cleavable hydroxyl protect beneficial pharmacological activity . ing group ” or “ bio - cleavable hydroxy protecting group ” is As used herein , the term “ alkyl” means a branched or intended to refer to a group that can be selectively attached straight- chain monovalent alkyl radical , having one to six to the oxygen atom by chemical modification of the carbon atoms such that the alkyl group is designated as alkyl hydroxyl group so as to selectively inhibit the participation C . - C . or C . - C . alkyl or alkyl C . .. This term is further 15 of the hydroxyl group in chemical reactions. Examples of exemplified by such radicals as methyl, ethyl, n -propyl , such bio - cleavable hydroxyl and phenolic - protecting groups isopropyl, n - butyl, s -butyl , t -butyl , isobutyl, amyl, n -pentyl , include the ester groups selected from acetate ester , neopentyl, valeryl and the like. methoxyacetate ester, benzoate ester, phenylacetate ester , As used herein , the term “ amino ” functional group of pivalate ester, phenoxyacetate ester, monosuccinate , nitrate , drugs or therapeutic agents refer to the drugs containing , in 20 ethyl carbonate and methoxymethyl carbonate . The proce addition to the required presence of one carboxylic acid dures for the formation of the above mentioned bio - cleav group , other reactive primary and secondary amines (both able hydroxyl protecting groups are based on the known acyclic and cyclic ) which also include drugs containing methods and their relevant references as cited in T . W . derivatizable NH -containing functional groups such as Greene , “ Protective Groups in Organic Synthesis ” , Third amide -NH , sulfonamide -NH , carbamate -NH , sulfamate - 25 Edition , 1999 , John Wiley and Sons, New York , are incor NH , hydrazide -NH , hydrazone -NH , semicarbazone - NH , porated herein as a reference . thiosemicarbazone -NH , urea -NH , and also encompass drug A s used herein , the term “ bio -cleavable carboxyl protect molecules with derivatizable NH -containing heterocyclic ing group ” or “ bio - cleavable carboxylic acid protecting sub - structures such as aziridine , azitidine , dihydropyridine , group ” is intended to refer to a group that selectively blocks indole , imidazole , benzimidazole , thiazole , benzothiazole , 30 the oxygen functionality within a carboxylic acid group so oxazole, benzoxazole , pyrrole , pyrrazole, benzopyrrozole , as to inhibit participation of the carboxylic acid group in pyrrolidine, piperidine, triazole , benzotriazoles, tetrazole , chemical reactions. Examples of such carboxylic acid pro and benzotetrazole . tecting groups include for example unsubstituted and sub As used herein , the term “ hydroxyl” or “ hydroxy ” func - stituted alkyl esters such as methyl and ethyl. The proce tional group of drugs or therapeutic agents refer to the drugs 35 dures for the formation of the above mentioned carboxyl containing , in addition to the required presence of one protecting groups are based on the known methods and their carboxylic acid group , other reactive hydroxyl (OH ) groups relevant references as cited in T . W . Greene , “ Protective (i . e ., these hydroxyl groups can be primary , secondary, Groups in Organic Synthesis ”, Third Edition , 1999 , John tertiary or phenolic in nature ) including hydroxyl groups of Wiley and Sons, New York , are incorporated herein as a hydroxamic acids , aldoxime, ketoximes of carbonyl -con - 40 reference . taining ( i. e . , aldehyde or keto groups ) drug molecules. As used herein , the term “ bio - cleavable sulfhydryl pro As used herein , the term “ sulfhydryl” functional group of tecting group ” or “ bio -cleavable thiol protecting group ” is drugs or therapeutic agents refer to the drugs containing, in intended to refer to a group that selectively blocks the thiol addition to the required presence of one carboxylic acid (SH ) functionality so as to inhibit participation of the thiol group , other reactive free sulfhydryl (SH ) groups and these 45 group in chemical reactions. Examples of such thiol pro can be primary , secondary, tertiary and thiophenolic in tecting groups include thioesters such as S - acetyl and S -ben nature . zoyl and unsymmetrical disulfides such as S - ethyl disulfide As used herein , the term “ halogen ” refers to fluorine , and S -t - butyl disulfide . The procedures for the formation of bromine , chlorine or iodine . the above mentioned bio -cleavable sulfhydryl protecting As used herein , the term " halide ” refers to fluoride , 50 groups are based on the known methods and their relevant chloride, bromide , and iodide . references as cited in T . W . Greene , " Protective Groups in As used herein , the term “ cycloalkyl” refers to a saturated Organic Synthesis ” , Third Edition , 1999 , John Wiley and mono -, bi- or polycyclic ring system containing a specified Sons, New York , are incorporated herein as a reference . number of carbon atoms. As used herein , the term “ bio -cleavable phosphate pro Unless otherwise stated , cycloalkyl rings containing 3 to 55 tecting group ” is intended to refer to a group that selectively 7 carbon atoms are preferred . Representative cycloalkyl b locks the phosphate [ P ( O ) (OH ) 2 ] functionality so as to groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclo - inhibit participation of the free phosphate group in chemical hexyl, cycloheptyl and the like . reactions . Examples of such bio -cleavable phosphate pro As used herein , the term “ bio - cleavable amino protecting tecting groups include 2 - ( S -acetylthio ) ethyl (SATE ), 3 - piv group ” is intended to refer to a group that can be selectively 60 aloyloxy - 1 , 3 - dihydroxypropyl derivative , dithiodiethanol attached to the nitrogen atom by chemical modification of an derivative , 4 - acyloxybenzyl phosphate mono or diester amino group so as to selectively inhibit participation of the derivatives . The procedures for the formation of the above amino group in chemical reactions . However , these amino mentioned bio - cleavable phosphate protecting groups are protecting groups can be cleaved in vivo either chemically based on the known methods and their relevant references as (pH dependent) or enzymatically . Exemplary bio -cleavable 65 cited in T . W . Greene , " Protective Groups in Organic Syn amino - protecting groups include carbamates ( urethanes ) thesis ” , Third Edition , 1999, John Wiley and Sons , New such as methyl, ethyl and t- butyl (i . e. , BOC or tert -butoxy York , are incorporated herein as a reference . US 9 ,844 ,599 B2 19 The term “ pharmaceutically acceptable salts ” refers to the salts of the compound of formula ( I) of the invention which are toxicologically acceptable and pharmaceutically utilis OH Ry able salts . NO2 The compounds of formula (I ) , which contains a basic 5 Dx O functionality , can be used according to the invention in the form of their addition salts of organic or inorganic acids . The Wherein , pharmaceutically acceptable acid addition salts of the pro X independently at each occurrence represents OH (i . e . , a drug compound of formula ( I ) include salts which retain the 10 primary , secondary , tertiary or phenolic hydroxyl group ), biological effectiveness and properties of the free bases and 0 -" PG , SH ( i. e ., a primary , secondary , tertiary or thiophe which are not biologically or otherwise undesirable . nolic sulfhydryl group ), S - SPG , CO2H or CCOO - PG , Examples of suitable inorganic acids include hydrochloric amino group ( i. e ., NH , or NH or N , which represent primary acid , hydrobromic acid , sulphuric acid , nitric acid , phos or secondary or tertiary amino groups, respectively ), phoric acid , perchloric acid , boric acid , and other inorganic 15 HN -APG . N - PG , a phosphate group ?i. e . , P ( = O ) (OH ) , ) , a acids known in the art . Examples of organic acids include : acetic acid , propionic acid , glycolic acid , pyruvic acid , protected phosphate group [ i. e . , P ( O ) (OPPG ) 2 ] , a carbo oxalic acid ,maleic acid , malonic acid , succinic acid , fumaric nyl group (i .e ., an aldehyde or keto group in the form of their acid , tartaric acid , citric acid , benzoic acid , cinnamic acid , bio - cleavable derivatives such as an acetal, oxime, hydra mandelic acid , sulfanilic acid , 2 - acetoxy benzoic acid , tolu zone , semicarbazone and the like ) or a mixture of one or enesulphonic acid , methane sulphonic acid , ethane disul 20 more types of these functional groups , where phonic acid , isethionic acid , ketoglutaric acid , benzenesul " PG represents a bio - cleavable hydroxyl protecting group phonic acid and other organic acids known in the art . such as acetyl group and the like ; The compound of formula ( I ) , which contains additional SPG represents a bio - cleavable sulfhydryl protecting acidic group ( s ) , can be used according to the invention as - group such as acetyl group , disulfide bond and the like ; base addition salts . Examples of pharmaceutically accept °PG represents a bio - cleavable carboxyl protecting group able base addition salts include those salts derived from such as lower ( alkyl C , -Co ) alkyl esters and the like ; inorganic bases such as alkali earth metal salts like sodium , " PG represents a bio - cleavable amino protecting group potassium , lithium , alkaline earth metal salts like calcium , such as acetyl, ethoxycarbonyl, 2 - acetylthioethoxycarbonyl magnesium , aluminium salts or salts of organic bases such 30 or 2 - ( 2 - aminoethyl) dithioethoxy -carbonyl group and the as lysine, arginine, triethylamine , dibenzylamine, piperidine - like ; or salts with ammonia . Particularly preferred are the ammo PPG represents a bio -cleavable phosphate protecting nium salts of the prodrugs of the present invention i. e . the group such as 2 - ( S -acetylthio ) ethyl ( SATE ) , 3 -pivaloyloxy compounds of formula ( I ). 1 , 3 -dihydroxypropyl derivative , dithiodiethanol derivative , The pharmaceutically acceptable salts of the present 35 4 -acyloxybenzyl phosphate mono or diester derivatives and invention can be synthesized from the subject compound the like; which contains a basic or acidic moiety , by conventional n represents 0 ( zero ) or 1 - 20 , preferably 0 ( zero ) or 1 - 10 , chemical methods. Generally the salts are prepared by yet preferably 0 (zero ) or 1 - 5 , yet preferably 0 ( zero ) or 1 - 2 ; contacting the free base or acid with stoichiometric amounts Ry is an alkyl C . C . or cycloalkyl C3- C7; preferably alkyl or with an excess of the desired salt - forming inorganic or 40 C . C : vet preferably alkyl C , Co: vet most preferably alkyl organic acid or base in a suitable solvent or dispersant or by C . (i . e . , CH3) ; anion exchange or cation exchange with other salts . Suitable ONO , (i . e ., nitrooxy ) group is covalently bonded to the solvents are , for example , ethyl acetate , ether , alcohols , other side of the linker; acetone , tetrahydrofuran ( THF ) , dioxane or mixtures of and in all its geometrical and stereoisomeric forms and these solvents . 45 also pharmaceutically acceptable salts thereof. In a first embodiment, the invention relates to compounds In a second embodiment, the invention encompasses a of the formula ( I ) , which are prodrugs of known drugs or compound of formula (I ) , wherein : therapeutic agents ; Dx is as defined in the first embodiment herein above ; Ry is alkyl C1- Co; 50 and in all its geometric and stereoisomeric forms and 0 Ry pharmaceutically acceptable salts thereof. H In a third embodiment, the invention encompasses a compound of formula (I ) , wherein : Dx Dx is as defined in the first embodiment herein above ; 55 Ry is alkyl C1- C4 ; yet preferably Ry is ethyl (CH2CH3 ) ; Wherein , yet most preferably Ry is methyl (CH2 ) ; Dx - C ( O ) O a drug or therapeutic agent containing at and in all its geometric and stereoisomeric forms and least one carboxylic acid group , which is covalently bonded pharmaceutically acceptable salts thereof. to the specified linker " C ( H ) (Ry ) " via a bio - cleavable ester I n a fourth embodiment, the invention encompasses a linkage ; 60 compound of formula ( I ) , wherein : Dx, the drug or thera Optionally , Dx - CEO )0 may contain , in addition to the peutic agent containing a carboxylic acid group capable of requisite one carboxylate group , additional reactive func - forming a covalent bio - cleavable ester linkage with a linker, tional group ( s ) [ ( X ) n ], which may be protected by appro referred to in the first , second , and third embodiments , is priate bio -cleavable protecting groups (PPGs ) . As a result , selected from the group comprising of an anti - inflammatory Dx - C ( O ) O can be represented alternatively as ( X ) n -Dx - 65 and analgesic agent, a cardiovascular agent , an anti -allergic CCOO . Thus , the compound of formula ( I ) could also be agent, an anti - cancer agent, an anti - depressant, an anti represented by the following alternative formula : convulsant agent, an anti - bacterial agent, an anti- fungal US 9 ,844 ,599 B2 21 22 agent, an agent, an anti -malarial agent, an anti - lipidemic A representative example of the cardiovascular agent is an agent, an anti- diabetic agent, an anti- ulcer agent , a vitamin ACE - inhibitor that is selected from the group comprising of and an anti - oxidant. benazepril , enalapril, enalaprilat, lisinopril , perindopril , qui In this embodiment , other variables of Ry in the com napril , ramipril, ramiprilate , trandolapril , alacepril, capto pounds of formula (I ) are as defined hereinabove; 5 pril, ceronapril, cilazapril, delapril , fosinopril, imidapril, in all its geometrical and stereoisomeric forms and phar - lisinopril, moexipril, moveltipril , omapatrilat, sampatrilat , maceutically acceptable salts thereof. spirapril, temocapril and zofenopril . In a fifth embodiment , in the compound of formula (I ) , the Another representative example of the cardiovascular anti - inflammatory and analgesic agent referred to in the agent is a sartan that is selected from the group comprising fourth embodiment hereinabove is selected from the group 10 of candesartan , olmesartan , losartan acid (EXP - 3174 ) , comprising of aceclofenac, acemetacin , acetamidocaproic telmisartan , and valsartan . acid , acetylsalicylsalicylic acid , actarit , alclofenac , 3 -almi Yet another representative example of the cardiovascular noprofen , amfenac , 3 - amino - 4 - hydroxybutyric acid , aspirin agent is an anti - thrombotic , anticoagulant or vasodilator ( acetylsalycilic acid ), balsalazide, bendazac , benoxaprofen , agent that is selected from the group comprising of acetyl bromprofen , bromfenac , 5 - bromosalicylic acid acetate , 15 salicylic acid (aspirin ) , argatroban , beraprost, dalteparin , bucloxic acid , bumadizone , butibufen , carprofen , cincho - daltroban , enoxaparin , iloprost, indobufen , isbogrel, hepa phen , cinmetacin , clidanac , clometacin , clonixin , clopirac, rin , lamifiban , lotrafiban , melagatran , nadroparin , ozagrel , diacerein , diclofenac , diflunisal, dipyrocetyl, enfenamic reviparin sodium salt, ridogrel, satigrel , taprostene, tinza acid , enoxolone , etodolac , felbinac, fenbufen , fenclozic parin , tirofiban and triflusal. acid , fendosal, fenoprofen , fentiazac , flufenamic acid , 20 Yet another representative example of the cardiovascular flunoxaprofen , fluocortolone- 21 -acid , flurbiprofen , fosfosal, agent is an anti - hyperlipidemic agent ( statin and fibrate ) that gentisic acid , ibufenac , ibuprofen , indomethacin , indopro - is selected from the group comprising of atorvastatin , beza fen , isofezolac, isoxepac , ketoprofen , ketorolac , lonazolac , fibrate , cerivastatin , ciprofibrate , clinofibrate , clofibric acid , loxoprofen , meclofenamic acid , mefenamic acid , mesala - clopidogrel free acid , fluvastatin , gemfibrozil , pitavastatin , mine , metiazinic acid , mofezolac , naproxen , niflumic acid , 25 pravastatin and rosuvastatin . olsalazine , oxaceprol, oxaprozin , pirazolac , pirprofen , pra - Yet another representative example of the cardiovascular noprofen , protizinic acid , salicysulfuric acid , salicylamide agent is an anti -anginal agent such as limaprost. 0 -acetic acid , salsalate , sulfasalazine , sulindac , suprofen , Yet another representative example of the cardiovascular suxibuzone, tiaprofenic acid , tolfenamic acid , tolmetin , agent is an anti - arrhythmic agent such as capobenic acid . tropesin , ximoprofen , zaltoprofen and zomepirac . 30 Yet another representative example of the cardiovascular A representative example of an anti - inflammatory and agent is an anti- hypotensive agent such as angiotensin II . analgesic agent is a NSAID that is selected from the group Yet another representative example of the cardiovascular comprising of aspirin , diclofenac , diflunisal, etodolac, feno - agent is a diuretic that is selected from the group comprising profen , flurbiprofen , ibuprofen , indomethacin , ketoprofen , of bumetanide , ethacrynic acid , furosemide , mercamph ketorolac , naproxen , sulindac and tolmetin . 35 amide , mercaptomerin sodium , mercumallylic acid , mersa Further in the sixth embodiment, the invention encom - lyl, piretanide and ticrynafen . passes a compound of formula ( I) ; wherein the cardiovas- Yet another representative example of the cardiovascular cular agent referred to in the fourth embodiment herein - agent is a vasodilator that is selected from the group com above is generically selected from the group comprising of prising of benfurodil hemisuccinate , beraprost, eledoisin , antihypertensive agents such as angiotensin converting 40 iloprost , prostaglandin E , and xanthinol niacinate . enzyme (ACE ) inhibitors, beta - blockers , sartans ( angio - Yet another representative example of the cardiovascular tensin II blockers ), anti -thrombotic and vasoactive agents, agent is a vasoprotectant such as chromocarb . anti - hyperlipidemic drugs ( including HMG -CoA -reductase Still further , in the seventh embodiment, the invention inhibitors ( statins )) , fibrates, anti - anginal agents , anti - ar encompasses a compound of formula (1 ) ; wherein the anti rhythmic agents , anticoagulants , anti -hypotensive agents , 45 allergic agent referred to in the fourth embodiment herein diuretics , vasodilators and vasoprotectants and is specifi - above is generically selected from the group comprising of cally selected from the group comprising of acifran , acipi a steroidal bronchodilator, a mast cell stabilizer and an mox , acetylsalicylic acid , alacepril , gama - aminobutyric anti - histamine and is specifically selected from the group acid , angiotensin , argatroban , atorvastatin , benazepril, ben comprising of acrivastine, amlexanox , bepotastine , cetiriz furodil hemisuccinate , beraprost , bezafibrate , bumetanide , 50 ine, fexofenadine , levocetirizine , lodoxamide , montelukast candesartan , capobenic acid , captopril, carmoxirole, caro - sodium , nedocromil , olopatadine, pentigetide and tranilast . napril , cerivastatin , chromocarb , cilazapril , ciprofibrate , A representative example of the anti- allergic agent is an clinofibrate , clofibric acid , dalteparin , daltroban , delapril , anti -histamine that is selected from the group comprising of dextrothyroxine , eicosapentaenoic acid , eledoisin , enalapril, acrivastine , bepotastine , cetirizine , fexofenadine , levocabas enalaprilat, enoxaparin , eprosartan , ethacrynic acid , fluvas- 55 tine, levocetirizine and montelukast sodium . tatin , fosinopril , furosemide, gemfibrozil , iloprost, imidapril , Still further , in the eighth embodiment , the invention indobufen , isbogrel , heparin , lamifiban , lifibrol, limaprost, encompasses a compound of formula ( I) ; wherein the anti lisinopril , losartan acid ( EXP - 3174 ) , lotrafiban , meglutol, cancer agent referred to in the fourth embodiment herein melagatran , mercamphamide , mercaptomerin sodium , mer above is selected from the group comprising of acitretin cumallylic acid , mersalyl, methyldopa , moexipril , mov - 60 ( etretin ) , aminolevulinic acid , amsilarotene , butyric acid , eltipril , nadroparin , omapatrilat , ozagrel , oxiniacic acid , chlorambucil, eflornithine hydrochloride, melphalan , perindopril, piretanide, pitavastatin , pravastatin sodium , methotrexate, minodronate (minodronic acid ), retinoic acids prostaglandin E1, quinapril, ramipril, reviparin sodium salt , ( including 13 - cis retinoic and all trans- retinoic acids ) , sulin ridogrel , rosuvastatin , sampatrilat , saralasin , satigrel , spi- dac , tamibarotene , and valproic acid . rapril , taprostene , telmisartan , temocapril, thyropropic acid , 65 Still further , in the ninth embodiment, the invention ticrynafen , tinzaparin , tirofiban , trandolapril, triflusal, val- encompasses a compound of formula ( I ) ; wherein the anti sartan , xanthinol niacinate, xenbucin and zofenopril . depressant referred to in the fourth embodiment hereinabove US 9 ,844 ,599 B2 23 24 is generically selected from antimaniacs and antipsychotic carboxylate ( i . e . , the parent drug of Tamiflu , which contains agents and is specifically selected from the group compris - a free carboxylic acid group ) and zanamivir . ing of amineptine, gabapentin , 5 -hydroxytryptophan ( ox - Still further, in the fourteenth embodiment, the invention itriptan ) , pregabalin , tianeptine, valproic acid and encompasses a compound of formula (I ) ; wherein the anti vigabatrin . 5 malarial agent referred to in the fourth embodiment herein Still further , in the tenth embodiment, the invention above is artesunate . encompasses a compound of formula ( I) ; wherein the anti Still further, in the fifteenth embodiment, the invention convulsant referred to in the fourth embodiment hereinabove encompasses a compound of formula (I ) ; wherein the anti is selected from the group comprising of gabapentin , pre diabetic agent referred to in the fourth embodiment herein gabalin , tiagabine , valproic acid and vigabatrin . 10 above is selected from the group comprising of mitiglinide , Still further, in the eleventh embodiment, the invention nateglinide , and repaglinide . encompasses a compound of formula (1 ) ; wherein the anti Still further , in the sixteenth embodiment, the invention bacterial agent referred to in the fourth embodiment here - encompasses a compound of formula ( I ) ; wherein the anti inabove is selected from the group comprising of acedia - ulcer agent ( including proton pump inhibitors ) referred to in sulfone , amdinocillin , p - aminosalicylic acid , amoxicillin , 15 the fourth embodiment hereinabove is selected from the amphomycin , ampicillin , apalcillin , apicycline, aspoxicillin , group comprising of acetoxolone , arbaprostil, carbenox azidocillin , aziocillin , aztreonam , bacitracin , balofloxacin , olone , cetraxate , ecabet , S -methylmethionine , proglumide, benzoylpas, benzylpenicillin , betamipron , biapenem , car - rebamipide , rosaprostol, rotraxate, sofalcone and trimopros benicillin , carindacillin , carumonam , cefaclor , cefadroxil, til . cefalexin , cefamandole , cefatiam , cefatrizine , cefazedone , 20 Still further , in the seventeenth embodiment, the invention cefazolin , cefbuperazone, cefclidin , cefdinir , cefditoren , encompasses a compound of formula ( I ) ; wherein the vita cefepime, cefetamet , cefixime, cefmenoxime, cefmetazole , min referred to in the fourth embodiment hereinabove is cefminox , cefodizime, cefonicid , cefoperazone , ceforanide , selected from the group comprising of biotin (vitamin H or cefoselis , cefotaxime, cefotetan , cefotiam , cefoxitin , cefo - coenzyme R ) , folic acid (vitamin M ), menadoxime , nicotinic zopran , cefpimizole , cefpiramide , cefpirome, cefroxadine , 25 acid ( niacin ), pantothenic acid or vitamin B ( a member of cefsulodin , ceftazidime, cefteram , ceftezole , ceftibuten , the B complex vitamins ) . ceftizoxime, ceftriaxone, cefprozil , cefuroxime, cefuzonam , Still further , in the eighteenth embodiment, the invention cephacetrile sodium , cephalexin , cephaloglycin , cephalori encompasses a compound of formula ( I ) ; wherein the anti dine , cephalosporin C , cephalothin , cephapirin sodium , oxidant ( including free radical scavengers ) referred to in cephradine, cilastatin , cinoxacin , ciproflaxacin , clavulinic 30 fourth , embodiment hereinabove is selected from the group acid , clavulanate , clinafloxacin , clometocillin , cyclacillin , comprising of a - lipoic acid , L - Carnitine , N - acetyl L -cyste dicloxacillin , difloxacin , enoxacin , epicillin , ertapenem , fen - ine, N -acetyl carnosine , raxofelast , tetomilast , and SCMC benicillin , fleroxacin , flomoxef , floxacillin , flumequine, fos - Lys ( S - carboxymethyl- L -cysteine Lysine salt . H2O ) . fomycin , fropenem , fusidic acid , garenoxacin , gatifloxacin , For the purpose of this invention , the eighteenth embodi gemifloxacin , grepafloxacin , hetacillin , hydnocarpic acid , 35 ment also encompasses a compound of formula ( 1 ) ; wherein imipenem , lomefloxacin , loracarbef, lymecycline, merbro - the drug containing carboxylic acid group is generically min , meropenem , metampicillin , methicillin , mezlocillin , selected from the drugs that fall under several other thera miloxacin , moxalactam , moxifloxacin , nadifloxacin , nafcil - peutic areas ( including those drugs that are classified on the lin , nalidixic acid , negamycin , noprysulfamide, norfloxacin , basis of their mechanism of action ) and is specifically ofloxacin , opiniazide , oxacillin , oxolinic acid , panipenem , 40 selected from the group comprising of an abortifacient/ pazufloxacin , pefloxacin , penicillin ( s ) , penimepicycline, interceptive such as prostaglandin Ez ; an anesthetic selected phenethicillin , phthalylsulfacetamide , phthalylsulfathiazole , from the group comprising of ecgonidine, ecgonine , pipemidic acid , piperacillin , piromidic acid , propicillin , hydroxydione sodium and gamma- hydroxybutyrate prulifloxacin , quinacillin , ritipenem , rosoxacin , rufloxacin , ( gamma- hydroxybutyric acid ) ; an anthelmintic selected salazosulfadimidine, salbactam , sitafloxacin , sparfloxacin , 45 from a group comprising of antimony sodium thioglycollate , succinylsulfathiazole , succisulfone , sulbenicillin , sulfach - kainic acid and stibocaptate ; an anti - acne agent selected rysoidine , sulfaloxic acid , 4 - sulfanilamidosalicylic acid , sul- from the group comprising of adapalene , isotretinoin and fanilic acid , tazobactam , teicoplanin , temocillin , ticarcillin , all - trans retinoic acid ; an anti - amoebic agent selected from tigemonam , tosufloxacin , trovafloxacin , tyrocidine and van - thiocarbamizine , and thiocarbarsone; an anti - arthritic or comycin . 50 anti -rheumatic agent selected from the group comprising of A representative example of the antibacterial agent is actarit , bucillamine, diacerein , gold sodium thiomalate , selected from the group comprising of amoxicillin , ampi lobenzarit, allocupreide sodium , clobuzarit and penicil cillin , cefadroxil , cefalexin , cefixime, cefotaxime, cefurox - lamine ; an anti - asthmatic agent selected from the group ime, cephalexin , ciprofloxacin , gatifloxacin , nadifloxacin , comprising of amlexanox , cilomilast (ariflo ) , cromolyn , nalidixic acid , norfloxacin , ofloxacin , oxacillin , panipenem , 55 domitroban , montelukast, nedocromil , ramatroban and sera salbactam and vancomycin . trodast ; an anti - gout/ uricosuric agent selected from the Still further , in the twelfth embodiment, the invention group comprising of carprofen , probenecid , orotic acid , encompasses a compound of formula ( I ) ; wherein the anti - oxycinchophen and ticrynafen ; an anti - diuretic agent such as fungal agent referred to in the fourth embodiment herein - oxycinchophen ; an anti - glaucoma agent such as unopro above is selected from the group comprising of amphotericin 60 stone; an anti- hypothyroid agent selected from tiratricol and B , azaserine , benzoic acid , candicidin , lucensomycin , thyroxine; an anti - prostatic hypertrophy agent such as epris natamycin , nystatin , propionic acid , salicylic acid and unde - teride; an anti -protozoal agent selected from eflornithine or cylenic acid ( 10 - undecenoic acid ) . fumagillin ; an anti - psoriatic agent such acitretin ; an anti Still further, in the thirteenth embodiment, the invention septic agent such as mandelic acid ; an anxiolytic agent encompasses a compound of formula ( I ) ; wherein the anti - 65 selected from calcium n - carbamoylaspartate or clorazepic viral agent referred to in the fourth embodiment hereinabove acid ( i . e . , clorazepate ) ; an astringent such as bismuth sub is selected from foscarnet sodium , Oseltamivir ( Tamiflu ) gallate ; a cathartic / laxative such as sennoside ; choleretic US 9 ,844 ,599 B2 25 26 agent selected from the group comprising of cholic acid , It is well known that long -term NSAID users are at cicrotoic acid , clanobutin , cyclobutyrol, cynarin ( e ) , dehy - increased risk of stomach ulcers , which is often a deterrent drocholic acid , deoxycholic acid , dimecrotic acid , exipro to long - term treatment . Acid control can reduce this risk and ben , fencibutirol, florantyrone , menbutone, 3 - ( 0 -methoxy concomitant use of an anti- ulcer agent such as a proton phenyl) - 2 - phenylacrylic acid , sincalide , tocamphyl and 5 pump inhibitor or a H2 receptor antagonist can thus be trepibutone ; an enzyme cofactor such as pantothenic acid ; an beneficial in reducing the incidence of ulcers associated with estrogen such as methallenestril; a gastroprokinetic agent chronic NSAID use . selected from alvimopan or loxiglumide; a hemostatic agent Thus , in the above embodiment, is provided a pharma selected from e -aminocaproic acid or tranexamic acid ; a ceutical composition comprising a therapeutically effective hepatoprotectant selected from the group comprising of 10 amount of a compound of formula ( 1 ) that are derived from S -adenosyl methionine , betaine , orazamide , timonacic ( thio - known anti - inflammatory agents such as aspirin , naproxen , proline ), methionine , protoporphyrin IX , thioctic acid and diclofenac , indomethacin , ibuprofen and the like and a tiopronin ; an immunomodulator selected from the group therapeutically effective amounts of an anti - ulcer agent such comprising of bucillamine, ubenimex , pidotimod , procoda- as a proton - pump inhibitor (PPI ) or a H2 receptor antagonist zole , romurtide and thymopentin ; immunosuppressant 15 (especially for chronic NSAID use ) , and a pharmaceutically selected from brequinar or mycophenolic acid ; a mucolytic acceptable carrier. selected from the group comprising of acetylcysteine, car representative example of the proton - pump inhibitor bocysteine , erdosteine , letosteine and stepronin ; a muscle (PPI ) is selected from the group comprising of omeprazole , relaxant such as baclofen ; a nootropic /cognitive enhancer esomeprazole, lansoprazole , rabeprazole , pantoprazole , ten selected from the group comprising of acetylcarnitine , 20 atoprazole and ilaprazole . Included within these examples hexacyclonate sodium and leteprinim ; a prostaglandin ana are salts , isomers , racemic compounds, crystals, poly log selected from the group comprising of beraprost , car morphs, amorphous forms and cocrystals of these examples. boprost, limaprost , prostacyclin , prostaglandin E1, prosta - A representative example of the H2 receptor antagonist is glandin E2, prostaglandin Fa rosaprostol, sulprostone , selected from the group comprising of cimetidine , famoti trimoprostil and unoprostone ; a sedative /hypnotic chloral 25 dine , nizatidine and ranitidine . Included within these selected from betainem or calcium 2 - ethylbutanoate ; a dop - examples are salts , isomers , racemic compounds, crystals , amine receptor agonist such as carmoxirole ; a 5a - Reductase polymorphs, amorphous forms and cocrystals of these inhibitor such as epristeride ; a reverse transcriptase inhibitor examples . such as foscarnet sodium ; thromboxane Az- receptor antago - It is understandable to those skilled in the art to whom this nist selected from the group comprising of altroban , 30 invention relates that the only requirement for a drug or domitroban , ramatroban , ridogrel and seratrodast and a therapeutic agent to qualify itself as a suitable candidate for thromboxane A , -synthase inhibitor selected from the group conversion to a compound of the invention , irrespective of comprising of isbogrel, ozagrel and ridogrel. its structural complexity or therapeutic use or mechanism of Still further, in the nineteenth embodiment, is provided a action , is the presence of at least one carboxylic acid pharmaceutical composition comprising a therapeutically 35 functional group in its structure . Thus , in an embodiment, effective amount of a compound of formula ( I) and a the following prophetic examples are provided to amply therapeutically effective amount of an anti - ulcer agent such illustrate the scope of the invention covering /encompassing as a proton -pump inhibitor (PPI ) or a H2 receptor antagonist the compounds of formula (I ) , wherein , the groups Ry , " PG , ( especially for chronic NSAID use ), and a pharmaceutically SPG , PG , " PG and PPG are same as defined in the forgoing acceptable carrier. embodiments :

I- D4 -Ry I- D5 -Ry 0 Ry Ry O ONO2 CH3 ONO2 (NO - Ketoprofen - An NSAID ) CH3 (NO - Flurbiprofen - An NSAID )

I -D6 -Ry I - D7 -Ry OMe 0 Ry O ONO Ry CH3 gru ONO2 mai(NO - Ibuprofene - An NSAID ) CH3 (NO - Indomethacin - An NSAID ) US 9, 844 ,599 B2 27 28 - continued I- D8 - Ry I - D9 - Ry o Ry Ry o H ONO2 O ONO2

(NO - Ketorolac - An NSAID ) ci (NO - Diclofenac - An NSAID )

hp I -D10 -R1 Ry I -D11 -Ry Go H3C O ONO2 ONO2 HC (NO - Valproic Acid - An anti- epileptic agent) CPU _ NH (NO -Mesalamine - An NSAID ) I -D12 -Ry I - D13 -Ry APG HN. CH3 o Ry apg ONO2 H3C ONO2 (NO -Gabapentin - An (NO -Pregabalin - An anti - epileptic agent) anti -epileptic agent) I -D14 - Ry I- D15 -Ry Ry Ry ? ONO2 ONO2

(NO - Vigabatrin - An anti -epileptic agent) H3C (NO - Tiagabine - An anti- epileptic agent ) ???? I- D16 -Ry I -D17 - Ry ?? ONO2 ? — hPG Ry 11111111100 - hPG 0 - hPG O Ry hPG - OH (NO - Cerivastatin - O ONO2 A HMG - CoA - reductase inhibitor ) (NO - Atorvastatin - A HMG - CoA - reductase inhibitor ) US 9, 844 ,599 B2 30 29 - continued I -D18 - Ry I -D19 -Ry

IPG ZONO2

? - hPG Ry - hPG 10 - hPG ONO2 (NO - Pitavastatin - A HMG - CoA - reductase inhibitor) (NO - Fluvastatin - areA HMG - CoA -reductase care inhibitor )

I- D20 -Ry I- D21 D21 - -Ry O ONO2 F CH3 " PG - 0 RY O = " PG - 0 CH? N ONOZ ? - hPG Ö- 2p8 RvRy On (NO -Rosuvastatin - A HMG - CoA -reductase inhibitor ) " PG OV- (NO - Pravastatin - A HMG - CoA -reductase inhibitor )

I - D22 -Ry I -D23 -Ry

H3C CH3 H3C CH3 O ONO2 O ONO2 ? Ry Ry © (NO - Ciprofibrate - (NO -Bezafibrate - A hypolipidemic agent) A hypolipidemic?? agent) ??? I - D24 -Ry I- D25 -Ry HzC CH3 ONO2 Eto WHNH Hu Ry N ONO2 CH3 (NO -Gemfibrozil - A hypolipidemic agent) Suyor otra(NO - Enalapril - An ACE inhibitorfor) US 9, 844 ,599 B2 31 3232 - continued I - D26 -Ry I -D27 - Ry NH?âPG SPG CH3

Ry

PG - OM WHNH ONO2 - ONO2 (NO - Captopril - An ACE inhibitor )

(NO -Lisinopril - An ACE inhibitor ) I -D28 -Ry I- D29 - Ry H3C H3C CH3 aPG H3C ONO OPG N - N N N - N N N N N - ONO , RY

(NO - Valsartan - An angiotensin ( NO - Candesartan - An angiotensin II receptor antagonist ) toII receptor antagonist ) be more I -D30 -Ry I- D31 - Ry

H3C Ry aPG N - N hPG - O11 ONO2 N N ? Ry

HC - — [NO - Losartan acid ( EXP -3174 ) - An postures(NO - lloprost - A vasodilator) angiotensin II receptor antagonist ] I- D32 - Ry I -D33 -Ry LOGONO2 CF3 Ö Ry E O ONO2 HN HN Ö Ry ( NO - Ridogrel - An antiplatelet agent ) aPG - NH jorter(NO -Melagatran - An anticoagulant) Otoman I- D34 -Ry OAC o Ry I- D35 -Ry OPG 11A - CH3 O ONO2 F30 Ry - ONO2 (NO - Triflusal - among An antiplatelet agent) (NO - Tirpfiban - An antiplatelet agent) them US 9, 844 ,599 B2 34 -continued smoI -D36 -Ry . I- D37 -Ry H3C COLONO2 0 Ry H3CO O Ry H??i H3CO 0 - hPG 0 - hPG OCH3 (NO -Limaprost - An anti- anginal agent ) (NO - Capobenic acid - An anti -arrhythmic agent) margohetI- D38 -Ry I -D39 -Ry

HC CH2 ZONO2 ONO2

Ry Ry nohy(NO - Etacrynic acid - A diuretic agent) obey(NO - Ticrynafen - A diuretic agent ) I- D40 -Ry I- D41 -Ry o Ry O ONO2 hPG - 0 hPG 0 Ry - O ONO2 Me Me (NO - Fexofenadine - An anti- histamine ) gomez(NO - Cetirizine - An anti -histamine ) Lato I- D42 -Ry o Ry ONO2 HN yoshiPG va (NO -Mephalan - An anticancer agent) I- D43 -Ry HN NN. CH3 NS o Ry NH2 O ONO2 0 0 - CPG pasaules(NO -Methotrexate - An anticancer agent) I -D44 -Ry I - D45 -Ry

APG LONOZ APG LONO Ry Gary GinoyRy (NO - Amineptine - An antidepressnat ) (NO - Tianeptine - An antidepressnat) US 9, 844 ,599 B2 35 36 - continued I- D46 -Ry I- D47 -Ry Ry 0 Ry hPG 1111111** 11111ll** ONO2 ONO2

? m “ PG - NH ( PG _ NH (NO - Amoxcillin - An anti - bacterial agent) (NO - Ampicillin - An anti- bacterial agent)

I - D48 -Ry o Ry ONO2

PGEN ( NO - Ciprofloxacin - An anti- bacterial agent)

I - D49 -Ry hpG NG

M WO - PG LO ONO2 hPG ** * 111 hPG hPG hPG PG

hp " PG OU HN - aPG (NO - Amphotericin B - An anti- fungal agent ) I -D50 -Ry P 0- 0 _ PG hPG - LO ONO2 " PG PPG PG guess Ry

hp PG

HN SaPG HN -- -- OPG (NO -Candicidin - An anti - fungal agent ) US 9, 844 ,599 B2 38 - continued » CorporateI - D51 -Ry I - D52 - Ry OOO- PG ( 0 ONO, HN NH IZJZ Ry HA HN JO JONO2 HANNN o RyRy (NO - Folic Acid - A vitamin ) (NO - Biotin - A vitamin ) I- D53 -Ry I -D54 -Ry hPG o Ry HPG O Tilta. Î H ONO2 O ONO2 "PG HINIHN . +101110 JI Ry N H ( NO -Artesunate - An anti- malarial agent) NH (NO -Zanamivir - An anti - viral agent ) I- D55 -Ry I - D56 -Ry Ry 0 Ry PPG - OLL ONO2 PPGPPGD ONO2

HN (NO -Zanamivir - An anti -viral agent) HN PG the CH ; (NO -Oseltamivir ( Tamiflu ) carboxylate - An anti - influenza drug ) I- D57 -Ry I - D58 -Ry Ry 0 Ry ? ONO2 0 ONO2

( NO -Mitiglinide - An anti -diabetic agent ) (NO - Repaglinide - An anti- diabetic agent) I - D59 - Ry I- D60 -Ry Ry O

O2NO 0 *11111111 Ry N

(111|1l (NO -Rebamipide - An anti - ulcer agent) H C 0 (NO -Acetoxolone - An anti- ulcer agent ) US 9, 844 ,599 B2 40 -continued I - D61- Ry I -D62 -Ry ONO2 H3C CH3 ONO2 RyRy S HzC ( NO -alfa - Lipoic acid - An antioxidant ) CH ; hPG (NO - Trimoprostil - An anti- ulcer agent)

I - D63 -Ry I- D64 -Ry 0 Ry CH3 H3C - ONO2 ONO2 11111111 PG

H3C (NO - Acetylcarnosine - An antioxidant) CHz ( NO - Raxofelast - An antioxidant ) I -D65 -Ry I - D66 -Ry Ry Ry ONO2 ONO2 H3CJN

- CH3 PG = 0 (NO - Ecgonidine - An anesthetic agent) hPG (NO - Prostaglandin E2 - An interceptive agent ) I -D67 - Ry I -D68a - Ry Ry ONO2 ONO2 RY PG wwwhp APG ( NO - Ecgonidine - An anesthetic agent) (NO - Kainic acid - An anthelmintic agent) and /or I- D68b -Ry I -D69 -Ry O Ry 1111111 CPG ONO2 ZOONO2 Ry H3C (NO - Kainic acid - An anthelmintic agent) hoque

(NO - Adapalene - An anti- acne agent) US 9, 844 ,599 B2 -continued I- D70 -Ry I - D71 -Ry H3C CH3 CHZ o Ry

ONO2 O ONO2 CH3 Grandin(NO - Allleras - trans - retinoic retinoic acid - - AnAn anianti - acnenene agenagent)) HN 4

NH2

- PG ( NO - Thiocarbamizine - An anti - amoebic agent)

I -D72 -Ry I -D73 -Ry

ONO2 HN ONO2 HN As

PG CH3 NH (NO - Actarit - An anti -arthritic agent) Qo( NO- -Thiocarburon Thiocarbarsone - An anti - amoebic agent)

I -D74 -Ry I -D75 - Ry CH3 0 Ry H3C SPG . H3CO 0 0 CHz O ONO2 111lllA apg NH (NO -Penicillamine - 0 ONO2 An anti - arthritic agent ) Ry (NO -Diacerein - An anti- arthritic agent ) I- D76 -Ry I -D77 - Ry OPG NH

LOONO2 ONO , Ry (NO - Amlexanox - Anti- asthmatic agent ) reporting hPG comment( NO -Montelukast - An anti- asthmatic agent ) US 9, 844 ,599 B2 43 44 43 - continued I -D78 -Ry I -D79 - Ry Ry - ONO2

ONO , CH3 aPG Hhnie sau(NO - Carprofen - An anti- gout agent) (NO - Seratrodast - Anti -asthmatic agent)

I -D80 -Ry I -D81 -Ry Ry

ONO2 HN ONO2 NH solis ö RyRy ( NO -Probenecid - An anti - gout agent ) (NO -Orotic acid - An anti - gout agent) I -D82 -Ry I -D83 -Ry Ry ONO2 0 Ry ONO

PG

hPG - 0 (NO -Unoprostone - An anti- glaucoma agent) (NO -Oxycinchophen - An anti- diuretic agent ) I -D84 -Ry I -D85 -Ry

ONO2 hPG vastH haryRy O NO (NO - Tiratricol - An anti- hypothyroid agent) Ry (NO - Epristeride - An anti- prostatic hypertrophy agent) I -D86 -Ry I - D87 -Ry Ry CHF2 ) ONO2 PG ONO , OPG “ PG _ NH “PG _ NH Ry (NO - R - eflornithine - An anti -protozoal agent ) and (NO - Thyroxine - An anti- hypothyroid agent) US 9, 844, 599 B2

- continued I - D88- Ry I - D89 - Ry ??Ry _ H ; C H ; C :«tiiiim ? &Di CH: CHF? ( NO- S -eflormithine - An alti - protOzoal agent ) Ry

( NO - Fumagillin - An anti- protOZOal agent )

I - D90- Ry I- D91 -Ry CH , CH , Ry Ry H , C ? 01 ' 0N02 H , C07 ( NO - Acitretin - An anti -ipsoriatic agent ) ( NO - Mandelic acido An anti- septic agent )

I- D92 -Ry I- D93a -Ry Ry

HN ' 0N03 FiDU?? PG O- IpG

CPU o Ry ( NO- Clorazepate - An anxiolytic agent ) CON02 fid

hp _ 00-upg

and / or ( NO - Sennoside - Alaxative agent} US 9, 844 ,599 B2 47 - continued I - D93b -Ry I - D94 - Ry o Ry hPG hPG hPG - tilll O ONO2

hp hPG

| 1111 O hPa hpG O2NO ? Pill H o Ry 111H (NO - Cholic acid - A choleretic agent) ONO2 hpo .

hPG 1110 hPG

hPG " PG (NO - Sennoside - A laxative agent)

I - D95 -Ry I -D96 -Ry H3C2 " PGO ONO2 ONO2 Ry (NO - Trepibutone - A choleretic agent) (NO - Cyclobutyrol - A choleretic agent )

I -D97 - Ry I -D98 -Ry H3C Ry OmhPG

X o 'ONO2ONO , ONO2 HzC CH3 H CO o Ry woogle(NO -Methallenestril - An estrogen ) HunSchool >110 (NO - Alvimopan - A gastroprokinetic agent) I- D99 -Ry I- D100 -Ry Ry o Ry - ONO2 aPG O ONO2 (NO - e - Aminocaproic acid - A hemostatic agent ) HN CH3

CH3 (NO -Loxiglumide - A gastroprokinetic agent ) US 9, 844 ,599 B2 49 50 49 - continued 50 I- D101 - Ry I -D102 - Ry Ry PG - , 0 - " PG CH3 O Ry APG ONO2 X HN NO2 (NO - Tranexamic acid - HNStyling “PG - NH A hemostatic agent) aPG ( NO - S -adenosyl methionine - A hepatoprotectant) I- D103 - Ry I- D104 -Ry CH ; RyONO2 spo H | | S ONO2 SPG (NO - Tiopronin - A hepatoprotectant ) que SPG NH (NO - Bucillamine - An immunomodulator and an antirheumatic agent ) I -D105 -Ry I - D106 -Ry Ry , ONO2 HN - OPG

HN

HN HN . (NO - Pidotimod - HN An immunomodulator ) NPG AONO2 RY PG (NO - Thymopentin - An immunostimulator ) I -D107 - Ry I- D108 - Ry hPG CH3 LONO2

CH3 CH3 HC ( NO -Mycophenolic acid - An immunosuppressant )

ONO2 Ry ( NO - Brequinar - An immunosuppressant ) I - D109 - Ry I -D110 - Ry CH3 aPG Ry H3CCH3 O ONO2 Ry CH3 (NO - Baclofen - muscle relaxant ) ONO (NO -Acetylcarnitine - A cognitive enhancer) US 99,, 844 , , 599 B2B 5252 - continued I -D111a - Ry I - D111b -Ry Ry O NO PG and /or CPG O ONO2 and / or Ry NH aprzNHaPG PG (NO - Carbocysteineglen - A mucolytic agent) (NO -Carbocysteine - A mucolyticals agent)

I - D111c - Ry I- D112 - Ry Ry À1 ? O NO . Yo ONO2 ONO2 Ry NH 0 aprzNHOPGapg 0 Ry yrale(NO - Carbocysteine - A mucolytic agent ) quor (NO - Isobogrel - A thromboxane A2- synthase inhibitor)

I - D113 - Ry I- D114 -Ry 0 Ry APG O ONO2

(NO -Ozagrel - A thromboxane A2 -synthase inhibitor ) -ONO2

(NO - Carmoxirole - A dopamine corte comentreceptor agonist )

I - D115 -Ry I -D116 - Ry ONO2 - ONO2

?Z

( NO - Domitroban - A thromboxane A2- receptor antagonist )

( NO - Ramatroban - A thromboxane A2 -receptor antagonist ) US 9 ,844 ,599 B2 53 54 and all their geometrical and stereoisomeric forms and also -continued pharmaceutically acceptable salts thereof ; I- D2 - R4 In a specific embodiment, the invention encompasses a compound of formula (I ) selected from the list comprising of: NO

I - D1- R1 Me01Meo - CH3 (NO -Naproxen ) 10 H3C 0 0 CH3 I- D3 -R1 LI NO2 cora O - NO, 15 C1 O CHZ (NO - Aspirin ) (NO - Chlorambucil ) 20 I -D1 - R2 and their geometrical and stereoisomeric forms and also pharmaceutically acceptable salts thereof; CH3 The compounds of formula ( 1 ) may contain a double HC o bond , an asymmetric or a chiral center either in the linker in 25 the drug molecule , and therefore can exist in different O - NO2 geometrical and stereoisomeric forms. In the structures shown herein , where the stereochemistry of any particular chiral atom is not specified , then all stereoisomers are Jean(NO - Aspirin ) contemplated and included as the compounds of the inven tion . The term " chiral” refers to molecules which have the property of non - superimposability of the mirror image cohort , while the term “ achiral” refers to molecules which I- D1 - R3 are superimposable on their mirror image partner. It is 35 intended that all stereoisomeric forms of the compounds of formula (I ) of the invention , including but not limited to , H3C CH3 diastereomers (when a parent drug , like in naproxen , con tains a chiral centre ) and enantiomers , as well as mixtures NO , thereof such as racemic mixtures, form part of the present 40 invention . Thus , compound of formula ( 1 ) according to the present invention can exist as enantiomers, can be present in enantiomerically pure form , both as levorotatory and as (NO - Aspirin ) dextrorotatory antipodes , in the form of racemates and in the I - D2 -R1 form of mixtures of the two enantiomers in all ratios. In the CH3 45 case of cis / trans isomerism the compound of formula ( 1 ) includes cis or trans forms or mixtures of these forms in all NO2 ratios; preferably exists either in cis form or trans form . The ) CH3CHz preparation of individual enantiomer or diastereomer from Me01 the racemates of the compounds of the present invention (NO -Naproxen ) 50 represented by the formula ( 1 ) can be carried out, if desired , I - D2 -R2 by separation methods known in the art. For instance , the CH3 racemic forms can be resolved by physicalmethods , such as com fractional crystallisation or separation by chiral column chromatography . The individual optical isomers can be NO2 55 synthesized in the optically pure form by the use of enzymes or through asymmetric syntheses . If, for instance, a particu Me01 CH3 lar enantiomer of the compound of formula ( I) of the present (NO - Naproxen ) invention is desired , it may be prepared by derivatisation I - D2 - R3 with a chiral auxiliary whereby the resulting diastereomeric moreCH3 60 mixture is separated and the auxiliary group cleaved to provide the pure desired enantiomer . In case , the compound of formula (I ) contains additional basic functional group such as amino or an acidic functional group such as car boxyl, diastereomeric salts are formed with an appropriate Me0 65 optically active acid or base , respectively . Consequently , (NO - Naproxen ) compounds of formula ( 1 ) can exist in enantiomeric or core 3diastereomeric forms or in mixtures thereof. The processes US 9 ,844 ,599 B2 55 56 for preparation can utilize racemates , enantiomers or diaste and selective release of the constituent drug or therapeutic reomers as starting materials . When diastereomeric or agent and nitric oxide contained in the compounds of enantiomeric products are prepared , they can be separated formula ( I ) is beneficial . by conventional methods for example , chromatographic According to a further aspect of the invention , there is techniques or fractional crystallization . 5 provided a process for producing a compound of formula ( I) Unless it is specifically desired , the racemic or diastereo or a pharmaceutically acceptable salt thereof . meric mixture of compounds of the invention represented by The compound of formula ( 1) may be prepared by the the formula ( I ) can be used without resolving as the chirality method shown in Scheme 1 , wherein , the drug or therapeutic resides in the linker portion and the linker would be cleaved a gent contains just one carboxylic acid functional group and off either chemically or enzymatically , or by both means , to no other derivatizable functional groups . liberate the parent drug in its original form in vivo . One aspect of the invention includes a pharmaceutical composition comprising a therapeutically effective amount Scheme 1 of the compound of formula (I ) , or a pharmaceutically 15 Steps 1 acceptable salt thereof and one or more of pharmaceutically Oxalyl chloride, acceptable carriers, vehicles or diluents . DMF (1 or 2 drops ) , Another aspect of the invention includes a method of Dx OH DCM , RT , 3 h ( Dx LG ] treating a disease or disorder in a human ormammal where ( or ) Thionyl chloride / a chronic , sustained and selective release of the constituent 20 Dx — CO2H bromide, RT / Reflux Dx — C( = O ) — LG drug or therapeutic agent and /or nitric oxide from a com Wherein , pound of formula ( I ) is beneficial ; comprising administering LG = Cl or Br to a mammal or a human in need of the treatment a therapeutically effective amount of the compound of for Ry – CHO mula ( 1 ) . 25 Yet another aspect of the invention includes a method of Steps 2 ZnCl2, DCM , treating a disease or disorder in a human or mammal where -15° C . to RT a chronic , sustained and selective release of the constituent drug or therapeutic agent or nitric oxide is beneficial; Step 3 AgNO3, ? H Ry comprising administering to said mammal a therapeutically 30 H Ry Acetonitrile , effective amount of the pharmaceutical composition con DxDE O LGLG taining a compound of the formula ( I ) . N O RT or RefluxReflux In one aspect of the invention , the compounds of formula DxDx Dx - Ry — LG ( I) as mentioned in any one of the preceding embodiments 1 - Dx — Ry for use in the treatment of a disease or disorder where a 35 Wherein , chronic , sustained and selective release of the constituent ( I) LG = Cl or Br. drug or therapeutic agent and nitric oxide contained in the Wherein , compounds of formula ( I ) is beneficial. Dx and R , are same as define in the embodiments . In another aspect of the invention , the pharmaceutical composition according to the relevant preceding embodi- 40 Step 1 ments for use in the treatment of a disease or disorder where In this step , the drug or therapeutic agent containing a chronic, sustained and selective release of the constituent carboxylic acid group (Dx - CO , H ) is treated with carbonyl drug or therapeutic agent and nitric oxide contained in the chloride , for example oxalyl chloride, and DMF (catalytic compounds of formula ( I ) is beneficial. amount) , or thionyl chloride, in the presence of an organic Another aspect of the invention includes use of the 45 solvent, for example , dichloromethane to form a reactive compounds of formula ( I ) as mentioned in any one of the carbonyl derivative such as the acid chloride of formula preceding embodiments for the treatment of a disease or Dx - C ( O ) - LG (wherein LG = C1) . disorder where a chronic , sustained and selective release of Step 2 the constituent drug or therapeutic agent and nitric oxide The reactive acid chloride Dx - C ( O ) -LG is then coupled contained in the compounds of formula ( 1 ) is beneficial. 50 with the aldehyde Ry - CHO in the presence of a catalyst such Yet another aspect of the invention includes use of the as zinc chloride and a solvent such as dichloromethane to pharmaceutical composition as mentioned in relevant pre - form a compound intermediate Dx -Ry - LG . ceding embodiments for the treatment of a disease or Step 3 disorder where a chronic , sustained and selective release of The compound intermediate Dx - Ry -LG is subjected to the constituent drug or therapeutic agent and nitric oxide 55 nitration using silver nitrate in the presence of an organic contained in the compounds of formula (I ) is beneficial. solvent, for example , acetonitrile to form the compound Yet another aspect of the invention includes use of the I -Dx - Ry of formula ( I ), and if desired , the compound of compounds of formula ( I ) as mentioned in any one of the formula ( I ) is converted to its pharmaceutically acceptable preceding embodiments for the manufacture of medica - salt . ments for the treatment of a disease or disorder where a 60 In Scheme 1 , the variables Dx and Ry are as defined in any chronic , sustained and selective release of the constituent of the embodiments of the present invention with reference drug or therapeutic agent and nitric oxide contained in the to the compounds of formula ( I ) wherein Dx is a part of compounds of formula ( I ) is beneficial. drug / therapeutic agent containing at least one carboxylic Yet another aspect of the invention includes use of the acid group . pharmaceutical composition as mentioned in preceding 65 As mentioned above, in the synthesis of compounds of embodiments for the manufacture of medicaments for the invention of formula ( I ) , wherein , the drug or therapeutic treatment of a disease or disorder where a chronic , sustained agent contains, in addition to the required one carboxylic US 9 ,844 ,599 B2 57 58 acid functional group , other reactive functional groups such hydryl protecting groups , carboxyl protecting groups and as an amino, a hydroxyl ( including phenolic and hydroxyl phosphate protecting groups are listed in T . W . Greene , group of oxime derivative of a carbonyl group of an alde- “ Protective Groups in Organic Synthesis ” , Third Edition , hyde or keto group ), a sulfhydryl, a phosphate , additional 1999 , John Wiley and Sons, New York , and incorporated carboxyl group ( s ) or a mixture of one or more types of these 5 herein as a reference . functional groups, such reactive functional groups should be A general method for the synthesis of compounds of masked with appropriate bio -cleavable protecting groups. invention represented by the formula ( I ) , wherein , the drug The methods for the formation along with their relevant or therapeutic agent contains , in addition to the required one references for all the known examples of bio - cleavable carboxylic acid functional group , one or more other reactive amino protecting groups , hydroxyl protecting groups, sulf functional groups is depicted in Scheme 2 .

Scheme 2 Step 1 ( HN ) Selective protection of the other functional groups with (PPG -Xns DxT OH appropriate bio - cleavable protecting groups ( PG ) DxT OH [For details , refer to Scheme 3 ] (HX ) , — Dx — CO2H A - 1 Oxalyl chloride DMF ( 1 or 2 drops ) Step 2 DCM , RT, 3 h or Thionyl halide RT /Reflux

OH Ry Step 3 ( PG -Xn ZnCl2, DCM , - 15°C . to RT ( PG - X ) 1G Dx O LG Ry – CHO DxDX LG mixA - 3 A - 2 AgNO3 Step 4 Acetonitrile RT or Reflux

OH Ry ( PGPG - X X ),n A NO2 1 — (* PG -X ), — Dx — Ry ( I ) US 9 ,844 ,599 B2 59 60 Wherein , the variables Dx and Ry are as defined in the presence of an organic solvent, for example , dichlorometh embodiments . X = 0 , S , NH ' ( i. e ., represents a primary amino ane to yield a reactive carbonyl derivative such as the acid group ), N ( i. e ., represents a secondary amino group ) or halide of formula (PGP - X ) n -Dx - C ( O ) -LG ( A - 2 ). C ( = O ) O ; 5 Step 3 n represents 0 ( zero ) or 1 -20 , preferably 1 - 10 , yet pref The reactive acid halide (PG? - X ) n - Dx - C ( O ) - LG ( A - 2 ) erably 1 - 5 , yet most preferably 1 - 2 ; is then coupled with the aldehyde Ry - CHO in the presence of a catalyst such as zinc chloride and a solvent such as *PG - a bio - cleavable protecting group of a hydroxyl (" PG ) dichloromethane to form an intermediate compound A - 3 . or sulfhydryl (?PG ) or carboxyl ( PG ) or amino ( “ PG ) or phosphate (PPG ) group ; Step 4 The intermediate compound A -3 is subjected to nitration LG = C1 or Br; using silver nitrate in the presence of an organic solvent, for 15 example , acetonitrile to form the compound of formula (1 ) Step 1 and if desired , the compound of formula (I ) is converted to its pharmaceutically acceptable salt. In this step , one or more reactive functional group ( s ) denoted by (HX ) n of the drug or therapeutic agent [ i. e . , The organic base used in the processes for the preparation (HX )n -Dx -CO2H or simply ‘Dx '] is / are selectively pro - - of the compound of formula (I ) as depicted in the afore tected by a potential bio - cleavable protecting group such as , mentioned schemes , may be selected from but not limited to for example , the ethoxycarbonyl group for amino protection , triethylamine , diisopropylethylamine, 4 - (dimethylamino ) the ethyl ester for carboxyl protection , the acetyl group for pyridine (DMAP ), pyridine or mixtures thereof. hydroxyl or sulfhydryl protection , the 2 -( S -acetylthio ) ethyl 25 (SATE ) group for phosphate protection , to obtain the cor - The organic solvent used in the processes for the prepa responding protected compound of formula (" PG - X ), - DX ration of the compound of formula ( I ) may be selected from CO2H (A - 1) . but not limited to dichloromethane (DCM ) , chloroform , dimethylformamide ( DMF) , tetrahydrofuran ( THF ) , Step 2 acetonitrile , ethyl acetate , diethyl ether or mixtures thereof. The protected compound of formula (PGP - X ) n - Dx - CO2H ( A - 1 ) (which still contains a free carboxylic acid group ) is Additional examples of bio -cleavable protecting groups, treated with carbonyl chloride , for example oxalyl chloride, particularly , bio -cleavable amino protecting groups, along and DMF (catalytic amount) , or thionyl chloride, in the with their method of synthesis , are shown in Scheme 3 .

Scheme 3

Ra Rq0 OH Dx Y DxOH

A - 1h A - 1S

X = S , RqC = O ) — LG or Rq [RqC ( = 0 )] 20 = Rqc ( 0 ) — LG or [Rqc ( O ) ] 20 Pyridine X = 0 Pyridine DCM O DCM Rq LG

Rp - N (HX ), 1 - 1 Foi DET OH TEA , DCM DxH X = NRp A - jal US 9, 844 ,599 B2 62 - continued LG Dx [Wherein , X = 0 , S , NRP (Rp is as defined ) or C ( = O ) O ] X = NRp TEA , DCM LG OCM1 -2 G

X = NRp X = NRp HO . OH x = NRp Rp TEA , DCM LG , LO A -1a2

LG Rp 1- 4 Dx 1.4 ?? HO Y Mis OH DxDxOH iyong Rp mgninger A - 193

RA - Dx OH 1 - 5 way ng the A -104 Dx yummy LY A- jas

Wherein , DCM ) in the presence of a suitable base such as triethyl

Rp is as defined above; 40 amine in a suitable solvent such as DCM . Synthesis of Intermediate A - 1a2 : Rq = alkyl C1- 6 or C6H5; The intermediate A - 142 can be synthesized by treating the r = 1 - 4 ; therapeutic agent Dx with the reactive intermediate 1 - 2 t = 0 - 2 ; ( which can be synthesized by reacting bis - ( 2 -hydroxyethyl ) LG = as defined disulphide with phosgene or its equivalent in the presence of Synthesis of intermediate A - 1 ” : The intermediateIntermediate A -- 1 ” can 45 a suitable base such as pyridine in a suitable solvent such as be synthesized by treating the therapeutic agent Dx with DCM ) in the presence of a suitable base such as triethyl either alkanoic acid halide ( i. e ., RqCeO )- LG ) or anhy amine in a suitable solvent such as DCM . dride [ i. e ., [RqC ( = O ) ] 20 ] in the presence of a suitable base Synthesis of Intermediate A - 1a * : such as pyridine in a suitable solvent such as DCM . The intermediate A - 103 can be synthesized by treating the One of the best examples in this category of drugs is 50 therapeutic agent Dx with the reactive intermediate 1 - 3 aspirin which is O -acetylated salicylic acid . (which can be synthesized by reacting dialkanoic acid halide Synthesis of intermediate A - 14: The intermediate A - 19 can with 2 -mercaptoethanol followed by reaction with phosgene be synthesized by treating the therapeutic agent Dx with or its equivalent in the presence of a suitable base such as either alkanoic acid halide ( i. e . , RaceO ) - LG ) or anhy - pyridine in a suitable solvent such as DCM ) in the presence dride [ i. e ., [RqC = O ) ]20 ] in the presence of a suitable base 55 of a suitable base such as triethylamine in a suitable solvent such as pyridine in a suitable solvent such as DCM . such as DCM . Synthesis of intermediate A - 1al: The intermediate A - 101 Synthesis of Intermediate A - 104 : can be synthesized by treating the therapeutic agent Dx with The intermediate A - 104 can be synthesized by treating the the reactive intermediate 1 - 1 (which can be freshly prepared therapeutic agent Dx with the reactive sulfone intermediate in two steps by reacting 2 -mercaptoethanol 60 1 - 4 ( t = 2 ) (which can be synthesized by reacting 2 - alkylthio ) ( HSCH CH2OH ) with either alkanoic acid halide ( i. e ., RqC ethanol or 2 - phenylthio ethanol with phosgene or its ( O ) -LG ) or anhydride [i . e. , [RqC ( O )] 20 ] in the pres- equivalent in the presence of a suitable base such as pyridine ence of a suitable base such as pyridine in a suitable solvent in a suitable solvent such as DCM to get the sulfide such as DCM to afford the S -acylated intermediate RqC intermediate 1 - 4 ( t = 0 ) and further oxidation with a suitable ( OSCH CH OH and further treating the S -acylated inter - 65 oxidizing agent such as m - chloroperbenzoic acid in a suit mediate with phosgene or its equivalent in the presence of a able solvent such as DCM ) in the presence of a suitable base suitable base such as pyridine in a suitable solvent such as such as triethylamine in a suitable solvent such as DCM . US 9 ,844 ,599 B2 63 64 Alternatively , the compound can be made by first treating m - chloroperbenzoic acid in a suitable solvent such as DCM ) the drug Dx with the reactive sulfide intermediate 1 - 4 ( t = 0 ) in the presence of a suitable base such as triethylamine in a to get the sulfide compound A -104 ( t= 0 ) and its further suitable solvent such as DCM . Alternatively , the compound oxidation with a suitable oxidizing agent such as m - chlo can be made by first treating the drug Dx with the reactive roperbenzoic acid in a suitable solvent such as DCM . 5 sulfide intermediate 1 - 5 ( t = 0 ) to get the sulfide compound Synthesis of Intermediate A - 103 : A - 195 ( t = 0 ) and its further oxidation with a suitable oxidiz The intermediate A - 143 can be synthesized by treating the ing agent such as m - chloroperbenzoic acid in a suitable therapeutic agent Dx with the reactive intermediate 1 - 5 ( t = 2 ) solvent such as DCM . (which can be synthesized by reacting 2 , 2 - thiodiethanol Potential examples of compounds of formula ( I ) contain with phosgene or its equivalent in the presence of a suitable 10 ing the above mentioned bio -cleavable amino -protecting base such as pyridine in a suitable solvent such as DCM and groups ( PG " ) and the plausible mechanisms of their cleav further oxidation with a suitable oxidizing agent such as age in vivo are shown in Chart 2 .

Chart 2

Rq Enzymatic cleavage

in vivo TZ + O ' s ( sulfhydryl- assisted 1, 5 - cycliztion ) DxT OH + S + HO Rq modeloAA Ry camente en Dx ETC Rp - N --- Dx - + Ry — CHO + [NO3 - NO ] Enzymatic cleavage

(Use of alkanoylthioethoxycarbonyl group as potential bio - cleavabe amino protecting group )

ON- OV 0 --* - Ry Ry NO2 Enzymatic NIR Enzymatic is Dx O NO2 cleavage cleavage Enzymatic cleavage Enzymatic cleavage

(I ) (Use of S , S -bis ( 2 ( carbonyloxy ) ethyl) butanebis ( thioate ) group as potential bio -cleavabe amino protecting group )

in vivo Lathy( sulfhydryl ry -assisted 1, 5 scycliation - cycliztion )

HO . + Rp $ + Ry — CHO + [NO ; — NO ] Mr OH DxTDx OH

Dx ETC mindDCA . . US 9, 844 ,599 B2 65 -continued 6

ONZO Dx ??Z Ry Ry Dx NO2 Enzymatic cleavage Enzymatic Dazzlecleavage ( I ) (Use of bis (2 ( carbonyloxyethyldisulfide group as potential bio - cleavabe amino protecting group )

in vivo sulfhydryl -assisted 1, 5 - cycliztion )

s + Ry — CHO + [NO3 - NO ] Rp OH

Dx ETC D ) or E ) weide ( O ) , ( O ) Dx Dx Dx ON NO or NO2 omogena fyrir? ? utanom iprirodi O qanun Enzymatic BD .: :B D Enzymatic Enzymatic cleavage cleavage cleavage (I ) (Use of bis ( 2 (carbonyloxyethyldisulfide or 2 - carbonloxyethylalkyl/ phenylsulfone groups as potential bio - cleavabe amino protecting groups)

in vivo | (Base - assisted B - elimination )

Rp SA- or > + Dx OH + CO2 + Ry — CHO + [NO3 - NO ] visumbanganDVS VS Dx

Wherein , The present invention furthermore relates to a pharma AA = Released alkanoic acid such as acetic acid , propionic ceutical composition containing a therapeutically effective acid , butanoic acid , pentanoic acid (valeric acid ) , hexanoic 50 amount of the compound of formula ( I ) which is a nitric acid (capric acid ) or heptanoic acid ( enanthic acid ) or oxide releasing prodrug of a known drug or a therapeutic benzoic acid ( i. e ., Rq- alkyl C1- 6 or CH3) ; ETC = Released ethylene thiocarbonate ; agent or its physiologically tolerable salts , with / without a DCA = Released dicarboxylic acid such as succinic acid , therapeutically effective amount of an anti - ulcer agent such glutamic acid , adipic acid or pimelic acid ( i. e ., r = 1 - 4 ) ; 55 as a proton -pump inhibitor (PPI ) or a H2 receptor antagonist , GSH - Glutathione ( reduced form ) ; and a pharmaceutically acceptable carrier, and to a process DVS = Divinyl sulfone (I .e . , t = 2 ) ; for the production of the pharmaceutical composition , which VS = Vinyl sulfone ( i. e . , t = 2 , Rq= as defined above ) ; comprises converting the compound of formula ( I ) into a The present invention also relates to the process of suitable administration form using an appropriate pharma resolution of the racemic mixture of the compound of 60 ceutically acceptable and physiologically tolerable excipi formula ( I ) or a pharmaceutically acceptable salt thereof: ent, and if appropriate , using further suitable active com The process of resolution of the racemic mixture com - pounds , additives or auxiliaries. prises reacting the racemic compound of formula ( I ) with a The compound of formula ( I ), which are the nitric oxide chiral auxiliary in the presence of a solvent, crystallising out releasing prodrugs of known drugs or therapeutic agents , the desired diastereoisomeric salt and subsequently treating 65 can be administered to a subject in need thereof in a variety it with a base to obtain the desired enantiomer of the of routes such as oral, for example in the form of pills , compound of formula (I ) . tablets , coated tablets , capsules , granules or elixirs . Admin US 9 ,844 ,599 B2 67 68 istration , however, can also be carried out rectally , for ( tablets , capsules) daily / weekly /monthly and in a dosage example in the form of suppositories , or parentally , for ranging from 1 mg to 5000 mg, preferably 1 mg to 2000 mg, example , intravenously, intramuscularly or subcutaneously, in a single dosage form or a multi -dosage form . in the form of injectable sterile solutions or suspensions, or The range set forth above is illustrative and those skilled topically , for example in the form of solutions or transdermal 5 in the art will be able to determine the optimal dosing of the patches, or in other ways, for example in the form of compounds of formula ( 1 ) of the present invention selected , aerosols or nasal sprays . based on clinical experience and the medical indication or The pharmaceutical composition according to the inven disease to be treated in a subject in need of the treatment. Another aspect of the present invention is to provide tion is prepared in a manner known per se , and by utilizing methods for the treatment of various medical conditions or methods well -known to one skilled in the art. Pharmaceu - 10 diseases or disorders in a subject comprising administering tically acceptable inert inorganic and /or organic carriers to a subject in need thereof a therapeutically effective and / or additives can be used in addition to the prodrug amount of a compound of formula (I ) . It has already been compound of formula ( 1 ) and / or its pharmacologically indicated herein above that the compounds of formula ( I) of acceptable salts . For the production of pills , tablets , coated the prepresent invention are prodrugs of known drugs or tablets and hard gelatin capsules it is possible to use , for 15 therapeutic agents containing at least one carboxylic acid example , lactose , corn starch or derivatives thereof , gum group . The specific class of therapeutic agents encompassed arabic , magnesia or glucose , etc . Carriers for soft gelatin within the scope of the invention are described herein above . capsules and suppositories are , for example , fats , wax , According to the present invention , the diseases or disorders natural or hardened oils , etc . Suitable carriers for the pro or the medical conditions for the treatment of which the duction of solutions , for example , injection solutions, or of 20 compounds of formula ( I ) of the present invention are used emulsions or syrups are , for example , water, physiological are those for which the parent drug molecule (represented by sodium chloride solution or alcohols , for example , ethanol, the variable Dx which encompasses specific therapeutic propanol, or glycerol, sugar solutions , such as glucose agents ) is conventionally used by a medical practitioner. solutions or mannitol solutions , or a mixture of the various Moreover, the compounds of formula ( 1) , which are the solvents which have been mentioned 25 prodrugs of known drugs or therapeutic agents , in all like The pharmaceutical composition of the invention also lihood are advantageous over the parent drug molecules or prodrugs of the parent molecule known hitherto in the prior contain additives such as, for example , antioxidants , emul art in terms of comparable or potentially superior oral sifiers , preservatives, colouring agents and flavouring bioavailability , reduced adverse effect, for instance , gastric agents . The pharmaceutical composition also may also con irritability caused by NSAIDS , etc . tain two or more prodrug compounds of formula (I ) and / or 30 It is understood that modifications that do not substan their physiologically tolerable salts . Furthermore , in addi tially affect the activity of the various embodiments of this tion to at least one prodrug compound of formula (I ) and /or invention are included within the scope of the invention its physiologically tolerable salts , the pharmaceutical com disclosed herein . Accordingly , the following examples are position can also contain one or more other therapeutically intended to illustrate but not to limit the scope of the present or prophylactically active ingredients . 35 invention . It would be understood by persons skilled in the art that the amount of the compound of formula ( I ) (prodrugs of EXPERIMENTAL known drugs or therapeutic agents ) that is contained in the pharmaceutical composition will depend upon the equimolar The abbreviations and terms that are used herein : amount of the parent drug molecule included therein . Gen - 40 (COC1 ) 2 : Oxalyl chloride erally , the amount of the prodrug used in the treatment DMF: N , N -Dimethylformamide methods is that amount which effectively achieves the DCM : Dichloromethane desired therapeutic effect in subjects being treated for a CBr4: Carbon tetrabromide particular disease . Naturally, the dosages of the various TPP : Triphenylphosphine prodrugs encompassed in the compounds of formula (I ) will 45 EtoAc or EA : Ethyl acetate vary somewhat depending upon the parent drug molecule , PE : Petroleum ether rate of in vivo drug hydrolysis , etc . RT: Room Temperature The pharmaceutical composition contains about 1 to 99 , ACN : Acetonitrile preferably about 1 to 80 % and most preferably from about ZnC1, : Zinc Chloride 10 to 70 % by weight of the prodrug compound of formula 50 AgNO . : Silver Nitrate ( I ) and / or the physiologically tolerable salts of prodrug TFA : Trifluoroacetic acid compound of formula ( I ) . The effective amount ofthe active HPLC : High Performance Liquid Chromatography ingredient of prodrug compound of formula ( I ) and /or its TLC : Thin Layer Chromatography physiologically tolerable salts in the pharmaceutical com position in order to obtain a desired therapeutic effect varies 55 Example 1 from 1 to 5000 mg. The desirable dosage of the pharma ceutical composition to be administered can vary over a 1 - ( nitrooxy ) ethyl 2 -acetoxybenzoate I- D1 -R1 wide range . The selected dosage level can be readily deter mined by a skilled medical practitioner in the light of the The title compound was synthesized in 3 steps as shown relevant circumstances, including the condition (diseases or 60 in Scheme 1 and the experimental procedure is described disorder ) to be treated , the chosen route of administration below . depending on a number of factors, such as age, weight and physical health and response of the individual patient , phar Steps 1 and 2 : Synthesis of 1 - chloroethyl macokinetics , severity of the disease and the like, factors 2 -acetoxybenzoate D1- R1 - C1 known in the medical art. However, in order to obtain 65 desirable effects , it would be recommended to administer the To a stirred suspension of aspirin (40 .00 g , 222 .22 mmol) pharmaceutical composition in the form of oral tablets in dry DCM ( 250 mL ) were added oxalyl chloride ( 22 .80 US 9 ,844 ,599 B2 69 70 mL , 266 . 56 mmol) and a catalytic amount of DMF (4 -5 Step 3: Synthesis of 1 -( nitrooxy ) propyl drops ) at RT under nitrogen . The resulting mixture was 2 -acetoxybenzoate I- D1 - R2 stirred at RT for 3 hours and concentrated to afford aspirin acid chloride ( quantitative) as pale yellow oil. To a stirred Nitration of the chloro intermediate D1- R2 - C1 ( 1 . 93 g , solution of the acid chloride ( 11. 00 g , 55. 55 mmol) in dry 5 7 . 52 mmol) with AgNO3 ( 1 .53 g , 9 . 02 mmol) afforded the DCM ( 100 mL ) was added a catalytic amount of zinc desired nitro compound I -D1 - R2 ( 1 . 38 g , 65 . 0 % ) as light chloride ( 0 . 15 g , 1 . 11 mmol ) followed by drop wise addition green oil. ' H NMR (CDC12 , 300 MHz ) : 8 1 . 09 ( t , J = 9 . 0 Hz, of acetaldehyde ( 3 . 10 mL , 55. 55 mmol) at - 15° C . under 3H ), 1 .94 - 2 .04 ( m , 2H ) , 2 . 36 ( s , 3H ) , 7 .13 - 7 . 16 ( m , 2H ) , nitrogen . The reaction mixture was stirred at RT for 16 hours 7 . 35 ( t , J = 7 . 2 Hz, 1H ) , 7 .60 - 7 .63 ( m , 1H ), 8 . 04 (dd , J = 1 . 5 , and concentrated . The residue was dissolved in ethyl acetate " 7 . 8 Hz, 1H ) ; 13C NMR (CDC1z , 75 .47 MHz ) : 8 7 . 7 , 20 . 9 , ( 100 mL ), washed successively with water (3x100 mL ), 24 . 9, 96 . 9, 121. 7 , 124 .1 , 126 .2 , 132 .0 , 134 . 8 , 151. 0 , 162 .2 , saturated sodium bicarbonate solution (3x100 mL ) and brine 169. 5 ; MS (ES + ) m / z 358 . 2 [ M + H ] * (2x100 mL ) , dried over sodium sulfate and concentrated . The crude compound was purified by silica gel (200 - 400 Example 3 mesh ) column chromatography using a gradient of 5 to 15 % ethyl acetate in petroleum ether as eluent to afford the 1 -( nitrooxy )butyl 2- acetoxybenzoate I- D1 - R3 desired compound D1- R1- C1 ( 3 . 00 g , 23 . 0 % ) as colorless oil. ' H NMR (CDC12 , 300 MHz ) : 8 1 .91 ( d , J = 5 .7 Hz, 3H ) , Steps 1 and 2 : Synthesis of 1 - chlorobutyl 2 .39 (s , 3H ) , 6 . 75 ( q , J = 5 . 7 , 11 . 7 Hz, 1H ), 7 . 36 (t , J = 7 .8 Hz , 20 2 - acetoxybenzoate D1- R3 - C1 1H ) , 7 .60 - 7 .64 ( m , 1H ) , 8 .00 ( dd , J = 1 . 2 , 7 . 8 Hz , 1H ) The title compound was synthesized using aspirin (5 .00 g, Step 3 : Synthesis of 1 - ( nitrooxy ) ethyl 27 .78 mmol) and oxalyl chloride (3 .00 mL , 33 .34 mmol) to 2 - acetoxybenzoate I -D1 - R1 give aspirin acid chloride . The aspirin acid chloride was 25 reacted with butyraldehyde ( 1 .81 g , 25 . 18 mmol) in the To a stirred solution of 1 - chloroethyl 2 -acetoxybenzoate presence of catalytic amounts of ZnCl2 ( 0 . 068 g , 0 . 50 mmol ) D1- R1- C1 ( 3 .00 g , 12 .29 mmol) in dry acetonitrile ( 30 mL ) to give the corresponding chloro intermediate D1- R3 -C1 was added silver nitrate ( 3 . 10 g , 18 .44 mmol) at RT. The ( 2 . 93 g , 43. 0 % ) as yellow oil . ' H NMR (CDC12 , 300 MHz ) : reaction mixture was refluxed at 80 - 90° C . for 1 hour, 8 1 . 00 ( t , J = 7 . 5 Hz, 3H ) , 1 . 54 - 1 .62 ( m , 2H ) , 2 .00 - 2 . 15 ( m , filtered over celite and concentrated . The residue was re - 30 2H ), 2 .39 (s , 3H ), 6 .65 (t , J = 6 .0 Hz , 1H ), 7 .15 ( d , J= 7 .8 Hz, dissolved in DCM (70 mL ) ; the precipitated silver salt was 1H ) , 7 . 36 ( t , J = 7 . 5 Hz, 1H ) , 7 .63 ( td , J = 7 . 5 , 7 . 8 Hz, 1H ) , filtered over celite and the filtrate was concentrated ( this 8 .05 ( dd , J = 1 . 5 , 7 . 8 Hz, 1H ) ; 13C NMR (CDC13 , 75 . 47 process was repeated twice ) . The crude compound was MHz) : 8 13. 4 , 18 .2 , 21 . 1 , 40 . 2 , 124 . 1 , 126 . 1, 131. 9 , 151. 1 , purified by silica gel ( 200 -400 mesh ) column chromatogra - „ 162 . 1 , 169 . 5 ; MS (EST ) m / z 293 . 0 [ M + Na ] phy using a gradient of 5 to 15 % ethyl acetate in petroleum ether as eluent to afford I- D1 - R1 ( 2 .70 g, 81. 0 % ) as pale Step 3 : Synthesis of 1 -( nitrooxy ) butyl yellow oil . ' H NMR (CDC12 , 300 MHz ): 8 1 .66 ( d , J = 5 . 7 2 -acetoxybenzoate I- DILR3 Hz, 3H ) , 2 . 37 ( s , 3H ) , 7 . 14 ( d , J = 8 . 1 Hz, 1H ) , 7 . 27 ( q , J = 5 . 4 , 11 . 4 Hz, 1H ) , 7 .33 - 7 . 36 ( m . 1H ) , 7 .60 - 7 .64 ( m . 1H ) , 8 . 0 (dd , in Nitration of the chloro intermediate D1 -R3 - C1 ( 2 . 90 g , J = 1 .5 , 8. 1 Hz, 1H ) ; MS (ES ) m /z : 268. 1 [ M - H ] - 10 .71 mmol ) with AgNO3 ( 2. 18 g, 12 .85 mmol) afforded the The compounds of Examples 2 - 8 were synthesized as desired nitro compound I -D1 - R3 ( 1 .50 g , 47 . 0 % ) as light shown in Scheme 1 by following the experimental procedure green oil . ' H NMR (CDC12 , 300 MHz ) : 8 1 . 04 ( t , J = 6 . 0 Hz, for the compound exemplified in Example 1 . The charac 3H ) , 1 .50 - 1 .60 ( m , 2H ), 1 .89 - 1. 97 (m , 2H ), 2 .36 (s , 3H ) , terization data for the compounds of Examples 2 - 8 is 45 7 . 20 ( t , J = 5 . 7 Hz, 1H ) , 7 .35 ( t, J = 7 . 8 Hz, 1H ) , 7 .60 - 7 .63 ( m , described below : 1H ) , 8 .05 (dd , J = 1 . 5 , 8 . 1 Hz, 1H ) ; 13C NMR (CDC12 , 75 . 47 MHz ) : 8 13 . 6 , 16 . 8 , 20 . 9 , 33 . 3 , 96 . 0 , 121. 8 , 124 . 1 , 126 . 2 , Example 2 132 . 0 , 134. 8 , 151 .0 , 162 .2 , 169 . 5 ; MS (EST ) m / z 320 .0 [ M + Na] " , 336 . 0 [ M + K ] * 1 - (nitrooxy ) propyl 2 - acetoxybenzoate I -D1 - R2 50 Example 4 Steps 1 and 2 : Synthesis of 1- chloropropyl 2 -acetoxybenzoate D1- R2 -C1 ( 2S ) - 1 - (nitrooxy ) ethyl 2 - ( 6 -methoxynaphthalen - 2 yl) propanoate 1 -D2 - R1 The title compound was synthesized using aspirin ( 5 . 00 g , 55 27 .78 mmol) and oxalyl chloride (3 . 00 mL , 33 .34 mmol) to Steps 1 and 2 : Synthesis of ( 2S ) - 1 -chloroethyl 2 -( 6 give aspirin acid chloride which was reacted with propi methoxynaphthalen - 2 -yl ) propanoate D2- R1 - C1 onaldehyde (1 .46 g, 25 .23 mmol) in the presence of catalytic amounts of ZnC1, ( 0 . 068 g , 0 .50 mmol) to give the corre The title compound was synthesized using naproxen ( 5 .00 sponding chloro intermediate D1- R2 -C1 ( 1 . 96 g , 30 . 0 % ) as 60 g , 21 .71 mmol) and oxalyl chloride ( 5 .51 mL , 65 . 14 mmol ) yellow oil . ' H NMR (CDC13 , 300 MHz ) : 8 1 . 13 ( t, J = 7 .5 Hz, to give naproxen acid chloride which was reacted with 3H ), 2 .09 - 2 . 20 ( m , 2H ) , 2 . 39 (s , 3H ), 6 . 60 ( t, J = 3 . 0 Hz, 3H ) , acetaldehyde ( 1 .22 mL , 21 .71 mmol) in the presence of 7 . 15 (d , J = 8 . 1 Hz, 1H ) , 7 . 35 ( t, J = 7 . 2 Hz, 1H ), 7 .60 - 7 .63 ( m , catalytic amounts of ZnC1 , ( 0 . 060 g , 0 .43 mmol) to give the 1H ) , 8 .06 (dd , J = 1 .5 , 7 . 8 Hz , 1H ) ; 13C NMR (CDC13 , 75 .47 corresponding chloro intermediate D2- R1 - C1 ( 5 .10 g , MHz ): 89. 2 , 21. 0 , 31 . 6 , 76 . 6 , 77 .0 , 77 . 4 , 85 .6 , 122 . 2 , 124 . 1 , 65 80 . 0 % ) as yellow oil. ' H NMR (CDC12 , 300 MHz ) : 8 1 .60 126 . 1 , 131 . 9 , 134 . 7 , 151 . 1 , 162 . 1 , 169 .6 ; MS ( ES + ) m / z ( d , J = 3 . 0 Hz , 1 .5H ) , 1 .62 ( d , J = 3 .6 Hz , 1 . 5 Hz) , 1 . 70 ( d , 256 .3 [M + H ]+ J = 5 . 7 Hz, 1 . 5H ) , 1 .77 ( d , J = 5 . 7 Hz, 1 .5H ) , 3 .89 ( q , J = 7 . 2 Hz , US 9 ,844 ,599 B2 72 1H ) , 3 . 93 ( s , 3H ), 6 .50 - 6 .61 ( m , 1H ) , 7 .14 - 7 . 18 ( m , 2H ) , ( 4 .50 g , 65 . 0 % ) ; ' H NMR ( CDC13 , 300 MHz ): 8 0 .82 (t , 7 .37 -7 .42 (m , 1H ), 7. 68 -7 .74 ( m , 3H ); MS (ES +) m / z 293 . 1 J = 7 . 3 Hz , 1. 5H ), 0 . 94 (t , J = 7 . 3 Hz , 1. 5H ), 1 . 26 - 1 .33 ( m , 1H ), [ M + H ] * 1 .42 - 1 .50 ( m , 1H ), 1. 59 - 1. 63 (m , 3H ) , 1 .88 -1 .98 (m , 2H ), 3 . 89 ( q , J = 7 . 1 Hz, 1H ) , 3 . 93 ( s , 3H ), 6 . 40 -6 .49 ( m , 1H ) , Step 3 : Synthesis of ( 2S ) - 1 -( nitrooxy ) ethyl 2 - 6 5 7. 14 -7 .18 (m , 2H ), 7 .38 - 7. 41 ( m , 1H ) , 7 .68 - 7 .74 ( m , 3H ) . methoxynaphthalen -2 -yl ) propanoate I- D2 -R1 Step 3 : Synthesis of (2S ) - 1 -( nitrooxy ) butyl 2 -( 6 Nitration of the chloro intermediate D2- R1 - C1 (4 .00 g , methoxynaphthalen - 2 - yl) propanoate 1 -D2 - R3 13 .66 mmol) with AgNO3 ( 4 .64 g , 27 .32 mmol) afforded the desired nitro compound I -D2 - R1 ( 3 .22 g , 74 . 0 % ) as yellow 10 Nitration of the chloro intermediate D2 -R3 - C1 ( 2 .00 g , solid .mp 69 - 71° C . ; ' H NMR (CDC13 , 300 MHz) : 8 1 .43 (d , 6 . 23 mmol) with AgNO3 ( 2 .11 g , 12 .46 mmol) afforded the J = 1 . 5 Hz, 1 . 5H ) , 1 . 54 ( d , J = 1 . 5 Hz, 1 . 5H ) , 1 . 58 - 1 . 59 ( m , desired nitro compound I -D2 - R3 as light yellow oil . Yield : 3H ) , 3 .88 ( q , J = 7 . 2 Hz, 1H ) , 3 . 94 ( s , 3H ) , 7 .02 - 7 .09 ( m , 1H ) , 57 . 0 % ; ' H NMR (CDC13 , 300 MHz) : 8 0 .84 ( t, J = 7 . 3 Hz , 7 . 14 - 7 . 19 ( m , 2H ) , 7 . 36 ( t , J = 8 . 9 Hz , 1H ) , 7 .65 ( d , J = 7 . 8 Hz , 1 . 5H ) , 0 . 96 ( t , J = 7 . 3 Hz, 1 . 5H ) , 1 . 24 - 1 . 47 ( m , 2H ) , 1 . 59 ( d , 1H ) , 7 .70 - 7 .73 ( m , 2H ) ; 13C NMR (CDC12 , 100 MHz) : 8 15 J = 3 . 0 Hz, 3H ) , 1 .65 - 1 . 83 ( m , 2H ) , 3 .89 ( 9 , J = 7 . 2 Hz, 1H ) , 17 . 6 , 18 . 7 , 45 . 7 , 55 . 7 , 81. 3 , 94 . 2 , 119 . 5 , 126 . 3 , 126 . 4 , 127 . 7 , 3 .94 ( s , 3H ) , 6 . 96 - 7 . 00 ( m , 1H ) , 7 . 14 - 7 . 19 ( m , 2H ) , 7 . 36 (t , 129 . 3 , 129 . 6 , 134 . 2 , 134 . 9 , 158 . 2 , 172 . 8 ; MS (ES ) m / z J = 8 . 6 Hz, 1H ) , 7 .65 ( d , J = 7 . 8 Hz, 1H ) , 7 .70 - 7 .73 ( m , 2H ) ; 318 . 1 ( M - H ) , MS ( EST) m / z 320 . 1 ( M + H ) * 13C NMR (CDC1z , 100 MHz ) : 8 13 . 8 , 13 . 9 , 16 . 9 , 17 . 2 , 18 . 5 , 18 . 6 , 33 . 4 , 33 . 5 , 45 . 6 , 45 . 7 , 55 . 7 , 134 . 2 , 134 . 7 , 134 . 9 , 158 . 1 , Example 5 20 173. 0 ; MS (ES + ) m /z 360 . 3 ( M + Na + (2S ) - 1 - (nitrooxy )propyl 2 - (6 -methoxynaphthalen - 2 Example 7 yl) propanoate I -D2 - R2 ( 2S ) - 1 -( nitrooxy )pentyl 2 - (6 -methoxynaphthalen - 2 Steps 1 and 2 : Synthesis of (2S ) - 1 - chloropropyl 25 yl) propanoate I- D2 - R4 2 - (6 -methoxynaphthalen - 2 - yl) propanoate D2- R2- C1 Steps 1 and 2 : Synthesis of (2S )- 1 -chloropentyl 2 -( 6 The title compound was synthesized using naproxen ( 5 .00 methoxynaphthalen - 2 -yl ) propanoate D2- R4 -C1 g , 21. 73 mmol) and oxalyl chloride ( 2 . 20 mL, 26 .08 mmol) The title compound was synthesized using naproxen ( 5 .00 to give naproxen acid chloride which was reacted with 30 g , 21 .73 mmol) and oxalyl chloride ( 2 . 20 mL , 26 .08 mmol) propionaldehyde ( 0 .74 mL , 10 . 08 mmol ) in the presence of to give naproxen acid chloride which was reacted with catalytic amounts of ZnCl2 ( 0 .082 g, 0 .60 mmol) to give the pentanal (0 .87 g , 10 .05 mmol) in the presence of catalytic corresponding chloro intermediate D2- R2 - C1 ( 0 . 90 g , amounts of ZnCl, ( 0 . 082 g , 0 . 50 mmol) to give the corre 30 . 0 % ) as dark yellow oil . H NMR ( CDC12 , 300 MHz) : S sponding chloro intermediate D2 -R4 -C1 ( 0 . 80 g , 23 . 0 % ) as 0 . 88 - 1 . 00 ( m , 3H ) , 1 .61 ( d , J = 6 . 0 Hz, 3H ) , 1 . 99 - 2 . 09 ( m , 35 dark yellow oil . ' H NMR (CDC12 , 300 MHz ): 8 0 .72 - 0 . 94 2H ) , 3 .89 - 3 . 98 ( m , 1H ) , 3 . 99 ( s , 3H ) , 6 .35 - 6 .43 ( m , 1H ) , ( m , 3H ) , 1 . 18 - 1 . 19 ( m , 2H ) , 1 . 25 - 1 .41 ( m , 2H ) , 1 .61 ( d , 7 . 14 ( dd , J = 2 . 1 , 2 . 4 Hz , 2H ) , 7 .41 (dd , J = 1 . 5 Hz each , 1H ) , J = 7 . 2 Hz, 3H ), 1 . 89 - 2 .05 ( m , 2H ) , 3 .87 - 3 . 97 ( m , 4H ) , 7 .71 ( t, J = 8 . 3 Hz, 3H ) ; MS (ES + ) m / z : 307 ( M + H ) + 6 .38 -6 .47 ( m , 1H ), 7 . 14 - 7 . 18 (m , 2H ) , 7 .38 -7 .41 (m , 1H ), 7 .67 - 7 . 74 ( m , 3H ); MS (ES + ) m / z : 335 . 2 ( M + H ) * Step 3 : Synthesis of (2S ) - 1 - ( nitrooxy ) propyl 2 - ( 6 - 40 methoxynaphthalen - 2 - yl) propanoate I -D2 -R2 Step 3 : Synthesis of (2S )- 1 -( nitrooxy )pentyl 2 -( 6 methoxynaphthalen - 2 -yl ) propanoate I -D2 - R4 Nitration of the chloro intermediate D2 -R2 - C1 ( 0 . 90 g , 2 .94 mmol) with AgNO , ( 0 : 59 g , 3 . 52 mmol) afforded the Nitration of the chloro intermediate D2 - R4 - C1 ( 0 . 80 g , desired nitro compound I -D2 - R2 ( 0 . 30 g , 30 . 7 % ) as yellow 45 2 .39 mmol) with AgNO3 ( 0 . 81 g , 4 . 70 mmol) afforded the oil . ' H NMR (CDC13 , 300 MHz ): 8 0 .83 (t , J= 7 .5 Hz, 3H ), desired nitro compound I -D2 - R4 (0 . 30 g , 34 .8 % ) as yellow 1 .61 - 1 .62 ( m , 3H ) , 1 . 80 - 1. 90 ( m , 2H ) , 3 . 86 - 3 . 91 ( m , 1H ) , oil . ? H NMR (CDC12 , 300 MHz ) : 8 0 .72 - 0 .77 (m , 1H ) , 3 . 93 (s , 3H ) , 6 .90 - 6 . 94 ( m , 1H ) , 7 . 13 - 7 . 18 ( m , 2H ) , 7 . 34 - 0 .87 - 0 . 98 ( m , 2H ) , 1 . 19 - 1 .21 ( m , 2H ) , 1 .34 - 1 . 43 ( m , 2H ) , 7 .36 ( m , 1H ), 7 .65 ( d , J = 7 .2 Hz , 1H ), 7 .72 (d , J = 8. 7 Hz , 2H ) ; 1 .60 -1 .61 (m , 3H ), 1. 66 - 1. 82 ( m , 2H ), 3. 85 -3 .93 (m , 4H ), 13C NMR (CDC12 , 75 .47 MHz ): 8 7 . 8 , 8 . 0 , 18 . 5 , 25 . 0 , 45 . 7 , 50 6 . 94 - 6 . 99 ( m , 1H ) , 7 . 13 - 7 . 19 ( m , 2H ) , 7 .34 - 7 . 40 ( m , 1H ) , 55 .7 , 97 . 1 , 106 . 1 , 119 . 5 , 126 .2 , 126 . 4 , 127 . 7 , 129 . 26 , 129 .6 , 7 .64 - 7 .73 ( m , 3H ) ; 13C NMR (CDC13 , 75 .47 MHz) : 8 13 . 7 , 134 . 2 , 134 . 7 , 158 . 1 ; MS (ES + ) m / z : 356 . 1 ( M + Na) 18 . 2 , 22 . 0 , 25 . 1 , 30 . 8 , 45 . 4 , 55 . 3 , 96 . 1 , 105 . 6 , 119 . 1 , 125 . 9 , 126 .1 , 127 . 3 , 129 .3 , 133 . 8 , 134 .6 , 133 .8 , 157. 8 , 172 .6 ; MS Example 6 (ES +) m / z : 384 .1 [M + Na ] * 55 (2S ) - 1 - (nitrooxy )butyl 2 - ( 6 -methoxynaphthalen - 2 Example 8 yl) propanoate I- D2 - R3 1 -( nitrooxy )ethyl 4 -( 4 -( bis ( 2 -chloroethyl ) amino ) Steps 1 and 2 : Synthesis of (2S ) - 1 - chlorobutyl phenyl )butanoate I -D3 - R1 2 - (6 -methoxynaphthalen - 2 - yl) propanoate D2- R3 -C1 60 Steps 1 and 2 : Synthesis of 1 - chloroethyl 4 - ( 4 - (bis The title compound was synthesized using naproxen ( 5 .00 (2 -chloroethyl ) amino )phenyl ) butanoate D3 - R1 - C1 g , 21 .71 mmol) and oxalyl chloride (5 . 51 mL , 65 . 14 mmol) to give naproxen acid chloride which was reacted with The title compound was synthesized using chlorambucil butyraldehyde ( 1 .94 mL , 21. 71 mmol) in the presence of 65 ( 1 . 00 g , 3 . 29 mmol) and oxalyl chloride ( 0 . 35 mL , 3 .95 catalytic amounts of ZnCl2 ( 0 .06 g , 0 .43 mmol ) to give the mmol) to give chlorambucil acid chloride which was reacted corresponding chloro intermediate D2- R3 - C1 as yellow oil with acetaldehyde ( 1 .50 mL , 26 . 32 mmol) in the presence of US 9 ,844 ,599 B2 73 74 catalytic amounts of ZnCl2 (0 . 04 g , 0 .33 mmol) to give the carried out PK studies on the promising prodrug 1 -D1 - R1 corresponding chloro intermediate D3 -R1 - C1 ( 0 .31 g , (NO -aspirin ) and aspirin in Wistar rats and the results are 31 . 0 % ) as dark brown oil . H NMR (CDC1z , 300 MHz ): presented in FIG . 2 and Table 7 . 1 . 79 ( d , J = 5 . 7 Hz, 3H ) , 1 . 92 - 1 .99 ( m , 2H ) , 2 . 38 ( t, J = 1 .5 Hz, Interestingly , both aspirin and its prodrug I- D1- R1 have 2H ), 2 . 59 (t , J = 7 . 2 Hz , 2H ) , 3 .62 - 3 .74 ( m , 8H ), 6 .56 ( q , 5 showns comparable bioavailability (AUCs : 436 . 8 + 26 .2 J = 5 . 7 , 1H ) , 6 .64 ( d , J = 8 . 4 Hz , 2H ), 7 . 10 ( d , J = 8 . 4 Hz, 2H ) ug * hr/ mL versus 397 . 6 – 28 . 0 ug * hr /mL ) in Wistar rats also . Step 3 : Synthesis of ( 1 - ( nitrooxy ) ethyl 4 -( 4 - ( bis ( 2 However, both aspirin and its prodrugs have shown strik chloroethyl ) amino )phenyl ) butanoate I -D3 - R1 ingly improved oral absorption in Wistar rats as compared to 10 that in Sprague -Dawley (SD ) rats (AUCs for Aspirin : Nitration of the chloro intermediate D3- R1 - C1 ( 0 . 10 g , 436 . 8 = 26 . 2 versus 91. 13 12. 20 at 30 mg/ kg equimolar dose ; 0 . 26 mmol) with AgNO3 (0 .050 g , 0 . 31 mmol) afforded the AUCs for prodrug I- D1 -R1 : 397 .6 + 28 .0 ug * hr/ mL versus desired nitro compound I - D3- R1 ( 0 .07 g . 70 . 0 % ) as brown 89 .78 : 10 . 20 ug * hr /mL at 44 . 83 mg /kg , which is equimolar oil . ' H NMR (CDC13 , 300 MHz ): 8 1 .55 (d , J = 5 . 7 Hz , 3H ), to 30 mg /kg dose of aspirin ). 1 . 90 - 1 . 97 ( m , 2H ) , 2 . 37 ( t , J = 7 . 2 Hz, 2H ) , 2 .57 ( t , J = 7 . 2 Hz, 15 Among the NO -naproxen series also , as shown in FIG . 3 2H ) , 3 .62 - 3 . 74 ( m , 8H ) , 6 .65 ( d , J = 8 . 7 Hz, 2H ) , 7 .03 - 7 .09 and Table 7, the prodrug I -D2 -R1 exhibited superior and ( m , 3H ) ; MS ( ES + ) m / z : 393 M + H ] + statistically significant increase in bioavailability (AUC : Experimental Data — Biological: Biological Evaluation 272 .60 + 8 .50 ug * hr/ mL , * * p < 0 .01 ) over that of naproxen The NO - aspirin prodrugs I -D1 - R1 , 1 -D1 - R2 , I - D1- R3 and 20 ( AUC : 207 . 80 - 18 . 20 ug * hr/ mL ) in SD rats . It is interesting NO -naproxen prodrugs I -D2 - R1 , 1- D2 -R2 , I- D2 - R3 , 1 -D2 to note their important PK parameters. i. e ., while Tmax for R4 were evaluated in vivo to establish their bioavailability naproxen was shown to be < 15 min with a Cmax of about and/ or anti -inflammatory efficacy . A few prodrugs with 55 ug /mL , the prodrug I - D2- R1 showed a Tmax around 1 h promising bioavailability were selected and evaluated fur with Cmax of about 50 ug /mL . It is also interesting to note ther for their nitric oxide release capabilities and their gastric 25 that the plasma drug concentration in prodrug treated ani ulcer sparing / inducing effects in comparison to their respec mals was found to be between 30 and 35 ug /mL during the tive parent drugs. period from 0 . 5 h to 6 . 0 h ( between 40 and 55 ug/ mL during The most promising NO -aspirin prodrug I -D1 - R1 was the period between 1 h and 4 h ). However , the plasma drug further evaluated for its ability to inhibit thromboxane B2 concentration in naproxen treated animals , although showed ( TXB2 ) and its efficacy was compared with that of aspirin at 30 a Cmax of above 55 ug /mL at 15 min , quickly reached to just equimolar dose . The prodrugs I -D1 - R1 (NO - aspirin ) and above 30 ug /ml in 2 hand to just above 20 ug /mL in a period I -D2 - R1 (NO -naproxen ) were also tested for their stability at of 4 hours and it further dropped to below 15 ug /ml in a different temperatures (RT and 50° C .) and in aqueous media period of 8 h . So , the prodrug I- D1 - R1 has exhibited (vehicles , such as aqueous solution of carboxymethyl cel controlled release of higher amounts of naproxen over a lulose ( CMC ) and polyethylene glycol (PEG ) over a pH 35 longer period of time (over 30 ug/ mL up to 6 h ) when range of 1 to 9 . compared to naproxen at equimolar doses. This prodrug is The promising NO - aspirin prodrug I -D1 - R1 was further therefore expected to offer pain relief for a longer period of tested for its stability in Simulated Gastric Fluid ( SGF ) , time than the parent drug naproxen although the parent drug Simulated Intestinal Fluid (SIF ) and 100 % human plasma and its unique capability to release aspirin in these media 40 is expected to offer quicker relief from pain than its prodrug thereby acting as a true prodrug of aspirin was determined . due to its faster absorption within 15 min of administration It is well known to the people skilled in the art that it has of the drug been a very difficult task to design a true ester prodrug of The remaining prodrugs in the naproxen series ( i . e . , aspirin due to the presence of a very labile acetyl group I- D2 - R2 , I -D2 - R3 and I- D2 -R4 ) exhibited either compa which undergoes preferential hydrolysis by plasma 45 rable ( I- D2 - R2 with an AUC value of 182 .70 + 8 .10 ug * hr/ esterases. Consequently , a vast majority of ester prodrugs of mL ) or slightly less ( i. e . , I - D2- R3 and I -D2 - R4 with AUC aspirin turn out be prodrugs of salicylic acid . values of 178 .60 + 8 . 10 ug* hr/ mL and 177 .40 + 4 . 10 ug * hr / Pharmacokinetics (PK ) of the Compounds of Invention in mL , respectively ) bioavailability when compared to that of Rats : naproxen with an AUC value of 207 .80 - 18 . 20 ug * hr/ mL The bioavailability ( AUC ) data presented for 50 and also showed some decreasing trend , although not sig NO -naproxen prodrugs correspond to the plasma concen - nificant, in bioavailability with increasing chain length of tration of the released parent drug , naproxen . However, as ( Ry " groun mentionedm above, the bioavailability data for aspirin or the NO - aspirin prodrugs correspond to the plasma concentration of the released salicylic acid rather than that of aspirin due 55 - TABLE 7 to the fact that both aspirin and NO -aspirin prodrugs pref Pharmacokinetic study data of compounds of invention : erentially undergo de- acetylation in vivo by plasma Plasma Aspirin / Naproxen esterases to give salicylic acid . AUC2, 3, 4 Among the NO - aspirin series , as shown in FIG . 1 and Compound Table 7 , prodrug I- D1 - R1 showed nearly comparable bio - 60 - (ug * hr/ mL ) availability to that of aspirin ( AUCs : 91 . 13 12 . 20 ug * hr/ mL Aspirin 91 . 13 + 12. 20 (436 .80 = 26 . 20 ) versus 89 .78 + 10 .20 ug * hr/ mL ) and the remaining two pro I - D1- R1 89 .78 + 4 . 90 ( 397. 60 + 28 .00 ) I -D1 - R2 73 . 54 + 4 .90 drugs not only showed less bioavailability to that of aspirin I -D1 - R3 53 . 56 + 15 .60 but also exhibited a decreasing trend in bioavailability with Naproxen 207 .80 18 . 20 increasing length of the alkyl chain . 65 I - D2 -R1 272 .60 8 .50 * * In order to assess the species - specific differences in oral I- D2 -R2 182 . 70 – 8 . 10 bioavailability of the prodrugs of this invention , we have US 9, 844 ,599 B2 75 76 TABLE 7 - continued TABLE 8 Pharmacokinetic study data of compounds of invention : Estimation of nitrate /nitrite release from the compounds of the invention Plasma Aspirin / Naproxen Plasma Nitrate /Nitrite AUC2, 3 , 4 5 Compound AUC (UM * h ) Compound ( ug * hr /mL ) Vehicle 371 .10 I -D2 - R3 178 . 6 + 8 . 1 I- D1 - R12 1481 .00 I - D2 - R4 177 .40 4 . 1 I - D2 - R13 686 .80 All the compounds were administered per oral either at 30 mg/kg equivalent dose of All the compounds were administered orally ; aspirin or 10 mg/ kg equivalent dose of naproxen . NO -aspirin at a dose equimolar to 10 mg/ kg dose of aspirin ; Average of pooled samples ( n = 3 ) . ” NO - naproxen at a dose equimolar to 30 mg /kg dose of naproxen . " Used SD Rats . 4AUC of aspirin corresponds to the released plasma salicylate. SUsed Wistar Rats . It was observed that significant amounts of nitric oxide ( in * * p < 0 .01 versus Naproxen . the form of nitrite / nitrate ) were released from these prom Anti- Inflammatory Efficacy of Representative Com ising compounds of this invention represented by formula pounds of the Invention : (I ) . It is reported that the anti - inflammatory activity of an InventionGastric : Ulcer -Sparing Properties of Compounds of the NSAID is directly proportional to the plasma concentration 20 of the drug (Nemmani , K . V . S ., et al ., Bioorganic and 20 The gastric ulcer- sparing potential of prodrugs I -D1 -R1 Medicinal Chemistry Letters, 2009, 19, 5297 -5301 and (NO - aspirin at 298. 85 mg/ kg , which is equimolar to 200 Pathan , A . R ., et al. , Inflammopharmacology , 2010 , 18 , mg/ kg dose of aspirin ) and I- D2 - R1 (NO -naproxen at 157 - 168 ) . The anti -inflammatory activity of compounds of 138 .67 mg/ kg , which is equimolar to 100 mg/ kg dose of formula (1 ) was estimated based on their respective oral o25 naproxennapro ) was assessed and compared with gastric ulcer bioavailability data . Moreover, the anti - inflammatory activ causing potential of their respective parent drugs, aspirin ity of the compounds of this invention represented by the and naproxen ( at doses of 100 mg/ kg ) in rats . The results formula ( 1 ) can be readily assessed in carrageenan - induced ( stomach images) from these experiments are presented in rat paw edema model according to the reported procedure FIGS. 5A and 6A , respectively . The results clearly establish 120 30 that none of the animals treated with prodrugs I -D1 -R1 ( A1- Swayeh , 0 . A ., el al. , Br. J . Pharmacol . 2000 , 129, 30 that(NO - aspirin ) and I -D2 -R1 (NO -naproxen ) showed any sig 343 - 350 ) . nificant development of gastric ulcers or lesions. However , Based on its better bioavailability , we expect the prodrug severe hemorrhagic lesions and ulcers were seen to develop I- D2 -R1 (NO -naproxen ) to show superior or at least com in rats administered with parent drugs, aspirin ( 100 mg/ kg ) parable anti - inflammatory activity to that of naproxenen inin the 35 and naproxen ( 100 mg/ kg ) . For clarity , the gastric lesion and carrageenan - induced rat paw edema model. ulcer area ( in mm²) for aspirin and its prodrug I- D1 -R1 Similarly , based on its nearly comparable bioavailability (NO -aspirin ) is shown in FIG . 5B . Similarly , the gastric to aspirin , it is expected that the prodrug I -D1 - R1 (NO - lesion and ulcer area ( in mm ) for naproxen and its prodrug aspirin ) would show comparable anti- inflammatory activity I- D2 -R1 (NO -naproxen ) is shown in FIG . 6B . to that of the parent drug aspirin . Inhibition of Serum Thromboxane B2 ( TXB2 ) Formation Estimation of Nitric Oxide Release from the Compounds by Aspirin and its Prodrug I- D1 - R1 : of the Invention : Aspirin is used as an antiplatelet agent for the treatment Nitric oxide is reported to act as a mediator of gastroin - of cardiovascular complications . Aspirin shows its antiplate testinal (GI ) mucosal defense by indirectly suppressing 45 let activity by inhibition of platelet cyclooxygenase ( COX ) various deleterious events resulting from NSAID - induced (COX is responsible for generation of a potent platelet inhibition of COX - 1 such as suppression of prostanoid activator thromboxane A2 ( TXA2 ) ), thus indirectly inhibit synthesis , reduction in mucosal blood flow andand overover - expres - ing the formation of serum TXB2 (which is a stable metabo sion of inflammatory mediators such as plasma tumor necro lite of TXA2 ) (Cox , D ., et al. , Stroke 2006 , 37 , 2153 -2158 ). sis factor alfa ( TNF - a ), etc . ( Lanas , A . Arthritis Res. Ther. 50 ItIt is thereforetherefore nosspossible to achieve complete suppression of 2008 , 10 ( Suppl. 2 ) , S4 ) . People with diabetes are believed platelet . TXA2 ( and also TXB2 ) formation via chronic to be associated with deficiency of nitric oxide (according to a research report from Florida University , which can be administration of aspirin at a dose of 30 mg/ daily (Patrig accessed at www .news . health . ufl. edu ) and may benefit from nani, P ., et al. J . Clin . Invest. 1982 , 69 , 1366 - 1372 ) . The the nitric oxide releasing compounds of this invention . For 55 antiplatelet activity of aspirin ( 30 mg/kg ) and its prodrug example, depleted levels of nitric oxide have been impli I- D1 - R1 ( at a dose equimolar to 30 mg/ kg dose of aspirin ) cated in diseases such as heart failure , pulmonary hyperten was evaluated in Sprague - Dawley (SD ) rats through esti sion and sexual dysfunction . We therefore evaluated the mation of serum TXB2 levels ( Esser, R . et al ., Br. J . nitric oxide releasing capability of the compounds of present Pharmacol. 2006 , 144 , 538 -550 ) and the experimental invention in rats by taking the two prodrugs I -D1 -R1 (NO - 60 results are presented in FIG . 7 . It was observed that aspirin aspirin ) and I- D2 -R1 (NO - naproxen ) as representative (30 mg/ kg , p . o . , 0 . d ., 7 days ) and its prodrug I -D1 - R1 ( 44 . 82 examples. The nitrate /nitrite release profile in the blood mg/ kg , equivalent to 30 mg/kg of aspirin , p .o ., o .d ., 7 days ) plasma which is an indirect measure of the nitric oxide exhibited nearly comparable inhibition of TXB2 formation released in the blood plasma was measured using Griess ( 75 .97 % versus 72. 59 % ) at equimolar doses . The result method by employing colorimetric nitrate / nitrite assay kit 65 unequivocally establishes that I -D1 - R1 , which exhibits sig from Fluka and the data obtained from the experiment is nificant antiplatelet activity (unique to the wonder drug presented in FIG . 4 and Table 8 . aspirin ), is indeed a true prodrug of aspirin (FIG . 7 ) . US 9 ,844 ,599 B2 77 78 Stability of Prodrugs I- D1 - R1 (NO - Aspirin ) and I -D2 -R1 aspect of preferential de - acetylation was much more pro (NO -Naproxen ) at RT and at 50° C .: nounced when the prodrug I -D1 - R1 was incubated in human Stability of prodrugs I- D1 - R1 (NO -aspirin ) and I- D2 - R1 plasma as shown in FIG . 10 . at RT and at 50° C . was tested and the results from the Thus, in human plasma, the prodrug I -D1 - R1 released experiments are presented in Table 9 . negligible amount (~ 5 % ) of aspirin (AUC : 352 uM * h versus TABLE 9 Stability of prodrugs I - D1- R1 and I - D2 - R1 at RT and at 50° C . a I - D1- R1 I- D2 - - R1 RT 50° C . RT 50° C . Time I- D1- R1 Asp SA I- D1 - R1 Asp SA I- D2 -R1 Nap I- D2 - R1 Nap Oh 99 . 14 % NIL NIL 99 . 14 % NIL NIL 99 .12 % NIL 99 . 12 % NIL 2 d — — 98 . 84 % NIL 0 . 1 % WN3d 98 .89 % NIL NIL 5 d - 98 . 18 % 0 . 3 % 0 . 14 % 18 d 98 . 95 % NIL NIL 25 d - 98 . 87 % 0 . 2 % 99 . 00 % 0 . 33 % 1 m 98 . 56 % 0 .13 % NIL 88 . 34 % 2 . 8 % 0 . 6 % - - - — aSamples were kept in capped vials . RT = Room Temperature. Asp = Aspirin . SA = Salicylic acid . Nap = Naproxen . d = days . — = not done . m = month Thus , the aspirin prodrug I -D1 -R1 was found to be very 6803 UM * h for equimolar amount of aspirin ) (FIG . 10 ) . stable at RT up to 1 month . However, when it was incubated 30 However , as expected , a large and proportional amount of at 50° C ., it degraded slightly ( ~ 1 % ) after 5 days and about salicylic acid was released , as shown in FIG . 11. In this case , 11 % after 1 month . After 1 month of incubation at 50° C ., plasma esterases preferentially hydrolyzed O - acetyl group about 2. 8 % of aspirin and 0 . 6 % of salicylic acid were of the prodrug to give salicylic acid as the major metabolite . generated . In the case of naproxen prodrug I -D2 -R1 , the Although the above examples ( prodrugs ) were made from prodrug remained stable both at RT and at 50° C . for up to 3 NSAIDs, the technology is not limited but can be extended 25 days (period of study ) and released only negligible to other therapeutic agents containing at least one carboxylic amounts (~ 0 .20 % at RT and ~ 0 . 33 % at 50° C .) of naproxen acid group . Thus, we have made one such example using an after 25 days . anti- cancer drug, chlorambucil , which is represented by In - vitro Metabolic Stability Studies on Aspirin Prodrug I- D3 - R1 (structure shown below ) . I- D1 - R1 in Biologically Relevant Fluids such as Simulated Gastric Fluid ( SGF) , Simulated Intestinal Fluid ( SIF ) and Human Plasma: I - D3 - R1 In order to confirm that the compound I -D1 -R1 (NO aspirin ) is indeed acting as a true prodrug of aspirin , itit was 45 CM incubated in biologically relevant fluids such as Simulated Gastric Fluid ( SGF ) , Simulated Intestinal Fluid (SIF ) and Cl CH3 human plasma and the corresponding results are presented in TH FIGS . 8 - 11 . The prodrug was evaluated at a concentration of - NO, either 100 uM or 1 mM and has shown dose dependent 50 (NO - Chlorambucil ) decrease / increase in the amount of aspirin released . As shown in the figures, aspirin was co -evaluated as a positive control under the same experimental conditions, at equimo - As anticipated , on incubation in SGF, the prodrug I- D3 lar doses , for a meaningful comparison of the results . R1 also showed quantitative release of the parent drug , In SGF, as shown in FIG . 8 , the prodrug I -D1 - R1 released 55 chlorambucil (See FIG . 12 ). significant amounts ( AUC : 10406 uM * h ) of aspirin , which The chlorambucil prodrug I -D3 -R1 , which is the lowest is only about 15 % less than that of aspirin ( AUC : 12348 carbon homologue in the series , decomposed in SGF to give UM * h ) at equimolar doses. 100 % of the parent drug chlorambucil with a half - life of less In SIF also , as shown in FIG . 9 , the prodrug I- D1 - R1 than 5 minutes. released significant amount of aspirin at 1 mM concentra - 60 tion . However, although the aspirin - release increased in a Example 9 dose - dependent manner , it was significantly less ( ~ 30 % ) than that of aspirin standard (AUCs : 136861 mM * h versus Pharmacokinetic Data for the Compounds of the 94862 mM * h ) at equimolar doses . In SIF , with its pH in the Invention range of ~ 6 - 7 , a certain percentage of the prodrug prefer - 65 entially underwent de - acetylation to give salicylic acid Representative compounds of formula ( I ) of the present derivative which further degraded to salicylic acid . This invention that are the nitric oxide releasing prodrugs of US 9 ,844 ,599 B2 79 80 known drugs or therapeutic agents containing at least one the nitric oxide releasing prodrugs of aspirin ( i. e . , I -D1 -R1 , carboxylic acid group , were subjected to pharmacokinetic I- D1 - R2 and I - D1- R3 , at a dose equivalent to 30 mg/ kg of study and the method and results of the study are presented aspirin ) and naproxen (i . e. , I- D2 - R1 , 1- D2 -R2 , I- D2- R3 and herein below : I -D2 - R4 , at a dose equivalent to 10 mg/ kg ofnaproxen ) were Animals : 5 administered orally to the remaining groups . Blood was Male Sprague -Dawley (SD ) rats weighing 150 - 220 g collected from orbital plexus of the rats according to a were used in the study ( Exception : Wistar rats were used for specific schedule ( 0 .25 , 0 . 5 , 1 , 2 , 4 , 6 and 8 h after dosing ) one study ) . The rats were fed normal standard laboratory and the plasma was separated from each sample by cen chow and maintained under standard environmental condi- trifugation for 5 min ( 1000xg ) at 4° C . Each collected tions ( room temperature of 22 + 2° C . ; 50 - 10 % relative 10 plasma sample ( 50 ul) corresponding to respective parent humidity : 12 hrs light -dark cycle ) . All experimental proce - drug ( i . e ., aspirin or naproxen ) and the aforementioned nitric dures mentioned below were approved by the institutional oxide releasing prodrugs of aspirin or naproxen was then animal ethics committee and were performed in accordance transferred to a micro centrifuge tube containing acetonitrile with standard guidelines of Committee for the purpose of (200 ul) , mixed by vortex and centrifuged for 5 min ( 1000x control and supervision of experiments on animals (CPC - 15 g ) at 4° C . The supernatant layer ( 150 ul) obtained after SEA ) ; Govt. of India for the experiment on animals . centrifugation was then transferred to HPLC vials. A ( 25 ul ) General Procedures : volume of each sample solution was injected into HPLC for The oral pharmacokinetic profile of the compounds of the analysis . The plasma concentration of salicylic acid or invention was studied in male Sprague - Dawley (SD ) rats . naproxen in rats after oral administration of the respective However , for one study , Wistar rats were used . For the 20 parent drugs ( i .e . , aspirin or naproxen ) and their respective purpose of these studies, the nitric oxide releasing prodrugs nitric oxide releasing prodrugs versus time intervals was of drugs containing a carboxylic acid functional group , e . g . plotted and the area under the curve was determined by naproxen and aspirin , which are encompassed in the com - trapezoidal rule (Gibaldi , M . and Perrier, D ., Pharmacoki pounds of formula ( I ), were selected as representative netics, Second edition , 15 :445 - 447 ) for each of the samples examples . The release profiles of parent drugs, naproxen and 25 corresponding to parent drug ( aspirin or naproxen ) and their aspirin from their nitric oxide releasing prodrugs were respective nitric oxide releasing prodrugs . The AUC values analyzed by a HPLC system . for the nitric oxide releasing prodrugs of aspirin and HPLC Sample Preparation and Standard Curve: naproxen were determined . HPLC : Waters Alliance analytical HPLC equipped with 2996 PDA detector and Empower software were used to 30 Example 10 analyze the samples. HPLC Column: Waters X - Terra RP - 18 reversed phase col Estimation of Nitrate /Nitrite Release from the umn , 150x3 . 9 mm , 5 um Compounds of the Invention In - Vivo HPLC Method : Flow : 1 mL/ min , detector set at 210 nm and at Maxplot ( 210 -400 nm range ) ; 35 Male Sprague -Dawley (SD ) rats ( 180 - 220 g ) were accli Solvent A : Acetonitrile ; matized for a week and fasted 12 - 14 hours prior to the Solvent B : 0 . 1 % TFA in water. commencement of the experiment. The representative com Injection volume: 20 ul pounds of formula ( I ) , i . e ., the nitric oxide releasing prod rugs of aspirin ( i . e . , I -D1 - R1 ) at a dose equivalent to 30 Elution Method : A Linear Gradient as Specified 40 mg /kg dose of aspirin and naproxen ( 1 -D2 -R1 ) at a dose Below equivalent to 10 mg/ kg dose of naproxen were administered orally to the rats . The blood sample was collected from the rats administered with each of the aforementioned nitric oxide releasing prodrugs of aspirin and naproxen according Time in min 0 - 2 2 - 10 10 -13 13 - 14 14 - 18 4 5 to a specific schedule ( 0 . 5 , 1 , 2 , 4 , 6 and 8 hours ) and the plasma was separated by centrifugation (1000xg ) for 5 min % A 20 20 -100 100 100 -20 20 at 4° C . The release profile of the nitrate /nitrite in the blood plasma which is an indirect measure of the nitric oxide Blood samples were collected from the rats and the released in the blood plasma was measured using Griess plasma was separated by centrifugation at 1000xg for 5 min 50 method by employing colorimetric nitrate /nitrite assay kit at 4° C . A stock solution of the parent drug was prepared by from Fluka . dissolving it in acetonitrile and working solutions of various The blood plasma samples were filtered using Millipore concentrations (0 .625 , 1 .25 , 2 .5 , 5 , 10 , 20 ug /mL ) were ultra - filtration 96 -well plate to remove the plasma proteins prepared by spiking the blood plasma with the naproxen having particle size of > 10 kDa. The assay was performed stock solution . Each plasma sample (50 ul) was then trans- 55 in a 96 -well plate according to standard procedure described ferred to a micro centrifuge tube containing acetonitrile (200 in the kit . The method comprised adding to the well , ul) , mixed by vortex and centrifuged for 5 min ( 1000xg) at standard ( sodium nitrate ) ( 80 ul ) of various concentrations 4° C . The supernatant layer ( 150 ul) obtained after centrifu - (0 , 20 , 40 , 60 , 80 and 100 uM ) followed by the reagents , gation was then transferred to HPLC vials . The sample nitrate reductase ( 10 ul) and enzyme co - factor ( 10 ul) . The solution (25 ul) was then injected in to HPLC for analysis . 60 plasma sample ( 80 ul) obtained from the blood sample A linear calibration curve between the naproxen concentra collected at various time intervals from the rats (0 . 5 , 1 , 2 , 4 , tion in plasma ( 0 .625 , 1. 25 , 2 . 5 , 5 , 10 , 20 ug /mL ) and the 6 and 8 hours ) were added to separate wells, followed by the peak area ratio was obtained . The rats were divided into reagents , nitrate reductase ( 10 ul) and enzyme co - factor ( 10 groups and three rats were placed in each group . Parent u l) . The plate was incubated for 2 h at room temperature on NSAID (i . e ., aspirin at a dose of 30 mg /kg or naproxen at a 65 orbital shaker ( 350 - 400 rpm ). Griess reagent A (50 ul) was dose of 10 mg/ kg ) was administered orally to one group of added to each well followed by incubation for 5 min and rats and the representative compounds of formula ( I) , i. e ., subsequently , Griess reagent B (50 ul) was added to each US 9 ,844 ,599 B2 81 82 well followed by incubation for 10 min . The absorbance of aspirin (100 mg /kg ) and naproxen ( 100 mg/ kg ) and their assay plate was measured by using a 96 -well plate reader respective nitric oxide releasing prodrugs I -D1 - R1 and I -D2 (Bio - Tek instruments ) at 540 nm . This procedure was car R1 ( at doses equivalent to 100 mg/ kg of aspirin and ried out for each of the aforementioned nitric oxide releasing prodrugs of aspirin and naproxen individually . A standard 5 naproxen , respectively ) were administered to overnight curve between the sodium nitrate concentration (UM ) ( 0 , 20 , 5 fasted rats of different groups. The animals were sacrificed 40 , 60 , 80 and 100 uM ) on X - axis versus absorbance values after 5 h of drug administration . The stomachs of the treated on Y -axis was plotted . The absorbance values of each of the animals were separated , perfused with 2 % formalin ( 10 mL ) . plasma samples collected at different time intervals corre and a large curvature was excised . The severity of the sponding to the aforementioned nitric oxide releasing pro mucosal damage was assessed on the basis of the size of the drugs of aspirin and naproxen from the rats was compared110 observed ulcer lesions in the images captured using a with the standard curve to determine the plasma nitrate stereomicroscope attached to a digital camera (Stemi 2000 , concentration in mice after oral administration of the afore Zeiss , Germany ). The Image Pro Plus software ( version 5 . 1 ) mentioned nitric oxide releasing prodrugs of aspirin and was used to quantify the hemorrhagic /ulcer lesions in pixels naproxen . The plasma nitrate concentration in rats after oral and to convert them into mm². The total area of lesions was administration of the aforementioned nitric oxide releasing 15 calculated for each treatment group and the measure of prodrugs of aspirin and naproxen versus time intervals was gastric ulcers (Mean : SEM ) (mm² ) was estimated ( FIGS. 5 plotted and the area under the curve was determined for each and 6 ) . of the samples corresponding to the aforementioned nitric oxide releasing prodrugs of aspirin and naproxen (FIG . 4 ) . Example 13 20 Example 11 Estimation of Serum TXB , Levels Determination of the Anti - Inflammatory Activity of In vivo TXB , inhibition potential of aspirin and NO the Compounds of the Invention aspirin prodrugs was assessed in Sprague - Dawley (SD ) rats ; With an intention to save resources and experimental 25 the serum TXB , levels were estimated according to the animals , anti- inflammatory activity of the compounds of this reported procedure ( R . Esser , R . , et al. , Br. J . Pharmacol. invention was not determined experimentally . The decision 2006 , 144 , 538 -550 ) . Thus, vehicle , aspirin (30 mg/ kg ) or was based on the observation that the anti - inflammatory aspirin prodrug I - DI- R1 ( 44 . 82 mg/ kg which is equivalent activity of a drug is generally shown to be directly propor to 30 mg/ kg dose of aspirin ) were administered orally to the tional to the amount of drug present in the blood õlasma. 30 overnight fasted SD rats . After six hours of drug adminis Since the AUC values ( i . e . , bioavailability ) of some repre tration , the blood samples were obtained from the rats by sentative compounds of this invention are comparable ?in retro -orbital plexus puncture under light isoflurane anesthe case of aspirin prodrug I -D1 - R1 (NO - aspirin ) ] or superior sia . The whole blood samples were immediately transferred [ in case of naproxen prodrug I- D2 -R1 (NO -naproxen )] to into glass tubes and allowed to clot at 37° C . for 60 min ; the those of their respective parent drugs aspirin or naproxen , 35 serum was separated by centrifugation (10 min at 2000 rpm ) we have intentionally not tested anti - inflammatory activity and kept at - 20° C . until assayed for TXB2. The serum of these promising NO -NSAIDs . However , the anti - inflam TXB , concentrations were determined by enzyme immuno matory activity of NO - aspirin ( i. e . , I- D1- R1 ) and NO - assay (EIA ) using commercially available TXB , estimation naproxen (i .e ., I -D2 - R1 ) and their respective parent drugs kit (Cayman Chemicals , USA ) , according to the method aspirin and naproxen can be assessed in carrageenan - in - 40 described in kit information booklet. duced rat paw edema model according to the reported procedure ( 0 . A . Al- Swayeh , O . A ., et al. , Br. J . Pharmacol. Example 14 2000 , 129, 343 - 350 ). Thus, Male Sprague -Dawley (SD ) rats are to be divided into three groups consisting of ten rats in In Vitro Metabolic Stability Studies in Biological each group . Parent drugs aspirin (30 mg/ kg ) or naproxen (10 45 Fluids mg /kg ) and NO -aspirin ( I -D1 - R1 , at a dose equivalent to 30 mg/ kg dose of aspirin ) and NO -naproxen ( I- D2 -R1 , at a dose Preparation of Biological Fluids equivalent to 10 mg/ kg dose of naproxen ) are to be dissolved Simulated Gastric Fluid (SGF ): in PEG 400 and administered orally to overnight fasted rats SGF was prepared according to the procedure described of different groups. One hour later , carrageenan ( 100 ul, 1 % 50 in Test Solution — USP . Thus, 0 . 2 g of sodium chloride and w / v ) is to be injected in to their paws. The control group is 0 . 32 g of purified pepsin (Sigma , derived from porcine to be given PEG 400 ( 1 mL /kg ) . The paw volume of the stomach mucosa with an activity of 800 to 2500 units per mg groups of rats administered with parent drugs and those of protein ) were dissolved in 0 . 7 mL of hydrochloric acid administered with prodrugs are to be measured before and sufficient water to make 100 mL . This test solution has carrageenan injection and also at a time period of 3 and 5 55 a pH of about 1 . 2 and was utilized for in - vitro studies. hours after the injection of carrageenan . The ( % ) inhibition Simulated Intestinal Fluid (SIF ) : of paw edema in rats administered with parent drugs (aspirin SIF was prepared according to the procedure described in and naproxen ) and NO -NSAIDS ( I - D1 - R1 and I - D2 -R1 ) Test Solution — USP . Thus, 0 . 68 g of monobasic potassium after 3 and 5 hours, respectively, are to be calculated and phosphate was dissolved in 25 mL of water followed by compared with that of the control group . 60 addition of 0 .2N NaOH ( 7 . 7 mL ) and water (50 mL ) . To this solution was added pancreatin ( 1 g ) and mixed ; the pH of the Example 12 resulting solution was adjusted to about 6 . 8 with 0 . 2N HC1/ 0 .2N NaOH and the solution , was diluted with water to Acute Gastric Ulcerogenesis Activity Study 100 mL. The solution was utilized for in - vitro studies . 65 Human Plasma: The ulcerogenic potential of NO -aspirin (i . e. , I- D1 - R1 ) Human plasma was similarly obtained by processing the and NO -naproxen (i .e ., I- D2 -R1 ) was assessed in rats . Thus, blood taken from healthy human male volunteers (age group US 9 ,844 ,599 B2 83 84 25 - 35 years ) who had not consumed any NSAIDS one week -continued prior to the collection ofblood . This plasma was utilized for I - D1- R3 the in - vitro experiments . In Vitro Metabolic Stability of Aspirin , Naproxen and their Respective Prodrugs I- D1 - R1 (NO - Aspirin ) and I -D2 - 5 H3C -CH3 R1 (NO -Naproxen ) in Simulated Gastric Fluid ( SGF) , Simu lated Intestinal Fluid ( SIF ) and Human Plasma : NO2 The solution of the test compound in acetonitrile ( 10 uL of 100 uM solution ) was dissolved in 990 uL of biological fluid ( SGF /SIF /Human Plasma ) . The resulting reaction mix - 10 (NO - Aspirin ) tures were incubated at 37° C . At specified time intervals, I - D2 -R1 aliquots (60 uL ) were withdrawn and added to acetonitrile CH3 ( 200 uL ) and mixed well by vortexing for 2 minutes . The mixture was centrifuged at 13000 rpm for 15 min at 4° C ., 15 and the supernatant analyzed by HPLC . The amounts (area NO2 percentages ) of the remaining intact prodrug ( if any ) and the CH3 released metabolite (s ) were estimated by HPLC . Me0 Statistical Analysis (NO -Naproxen ) Statistical analyses of data consisting of three or more 20 I - D2 -R2 groups were performed using one -way analysis of variance CH3 (one -way ANOVA ) followed by post- hoc Dunnett ' s mul tiple comparison test , and values of p < 0 .05 were considered NO2 as significant. For data consisting of two groups, analyses wereWO performed using student' s t test and values of p < 0 . 05 25 MeoMeO . were considered as significant. All analyses were carried out CH3 using GraphPad Prism version 4 .00 for Windows (GraphPad (NO - Naproxen ) Software , San Diego , Calif . , USA ). For data consisting of I - D2 -R3 only pooled /mean values , the statistical analysis could not CH3 be performed . 30 HPLC Analysis NO2 This was performed by using HPLC instrument (Waters alliance ), pump 2695 , and PDA detector 2996 with the o CH ; following chromatographic parameters : Wavelength - 210 Me01 nm ; Column -Waters X - Terra RP - 18 , 150x3 .9 mm , 5 um ; 35 (NO -Naproxen ) Injection volume , 25 uL ; Run time, 13 min . Mode of I - D2 -R4 operation was linear gradient with mobile phase A : Acetoni trile and B : 0 . 1 % TFA in water ( filtered and degassed ). Flow CH3 rate was 1. 0 mL/ min at 25° C . 40 NO2 The invention claimed is : 1 . A derivative of a therapeutic agent comprising aspirin , Meo - CH3 naproxen , or chlorambucil, selected from the group consist (NO -Naproxen ) and ing of: I -D3 - R1 45

I - D1 - R1 CH3 HC CH3 50 NO (NO - Chlorambucil) 55 or geometrical , stereo - isomers , or pharmaceutical composi (NO - Aspirin ) tions thereof. I - D1 - R2 2 . A pharmaceutical composition comprising a therapeu tically effective amount of the compound of claim 1 , or a - CH3 pharmaceutically acceptable salt thereof and one or more of H3C pharmaceutically acceptable carriers , vehicles or diluents . 3 . A method of treating a disease or disorder in a human ormammal where a chronic , sustained and selective release of the constituent drug or therapeutic agent and / or nitric 65 oxide is beneficial, wherein the disease or disorder is (NO - Aspirin ) selected from the group consisting of soft tissue inflamma tion , pain , arthritis , or a thrombotic cardiovascular event, US 9 ,844 ,599 B2 85 86 comprising administering to the mammal or human in need form the derivative of claim 1 and optionally conver of the treatment a therapeutically effective amount of the sion of the compound to its pharmaceutically accept compound of claim 1 . able salt. 4 . A method of treating a disease or disorder in a human 6 . A process for the preparation of the derivative of a ormammal where a chronic , sustained and selective release 5 of the constituent drug or therapeutic agent or nitric oxide is 5 therapeutic agent of claim 1 or a pharmaceutically accept beneficial, wherein the disease or disorder is selected from able salt thereof, wherein the process comprises the steps of: the group consisting of soft tissue inflammation , pain , arthri a ) selectively protecting a functional group of the thera tis, or a thrombotic cardiovascular event, comprising admin peutic agent; istering to said mammal a therapeutically effective amount , b ) treating the compound obtained in step a , with oxaly1 of the pharmaceutical composition as claimed in claim 2 . - chloride or thionyl chloride in the presence of dichlo 5 . A process for the preparation of the derivative of a romethane to yield a reactive acid chloride intermedi therapeutic agent of claim 1 or a pharmaceutically accept ate ; able salt thereof, wherein the process comprises the steps of : a ) reacting the therapeutic agent with oxalyl chloride or c ) reaction of the intermediate obtained in step b with an thionyl chloride to form a reactive acid chloride ; aldehyde in the presence of zinc chloride and dichlo b ) coupling the reactive acid chloride obtained in step a romethane to form an intermediate compound ; and with an aldehyde in the presence of a catalyst zinc d ) nitration of the intermediate compound obtained in step chloride and dichloromethane to form intermediate c with silver nitrate in the presence of a acetonitrile to compound ; and form the derivative of claim 1 or its pharmaceutically c ) nitration of the intermediate compound obtained in step 2020 acceptable salt . b with silver nitrate in the presence of acetonitrile to * * * * *