Indi an Journal of Chemistry Vol. 428, April 2003, pp. 910-9 15

Synthesis and anti-microbial activity of some derivatives

A K Padhy National In stitute of Science & Technology, Palur Hills, Berhampur-761 008, Orissa, India

and M Bardhan & C S Panda*

Synthetic Organic Laboratory, Deptt of Chemistry, Berhampur Uni versity, Berhampur-760 007, Orissa. India

Receil•ed 25 July 200 I; accepted (revised) II March 2002

4-Aryl-5-carboethoxy-6-mcthyl- 1, 2,3,4-tetrahydropyrimidin-2-ones have been synthesized from easil y avai lable start­ ing materials. The carboethoxy group at the C5-position of the pyrimidine ring is converted to corresponding hydrazide which in turn is condensed with cycli sin g agents such as aromatic aldehydes, CS2 etc. to give fu sed heterocycles. The fu sed heterocycles are then subjected to phenacyl ation to give Nr phenacylpyrimido-heterocycles in excellent yield. In a slightly modified way, uracil derivatives are condensed with to give Nrl)-cthoxycarbonyl derivati ves. The hy­ drazide derivatives of these Nr l)-ethoxycarbonyl derivatives subsequently react with 1,2-diketones to give corresponding pyrimido pyridazine derivatives.

Pyrimidines are of great importance in fundamental N-C-N reagents and I ,3-diketones, diesters and dini­ metabolism, for uracil, thiamine and cytosine are triles are typical C-C-C reagents. 1 three of the six bases found in the nucleotide • Many Thus, employing a slightly modified method ethyl derivatives of pyrimidine have been used as therapeu­ acetoacetate and cyanoethyl acetate (C-C-C unit) can 2 tic agents .3 . Several triazolo and pyrazolopyrimidines condense with urea or thiourea (N-C-N unit) in pres­ are found to possess antifungal and antileishmanial ence of diverse aromatic aldehydes to give pyrimidine activit/. Pyrimjdine derivatives are known to possess derivatives 1 and 2 in appreciable yields. The struc­ analgesic and anti-inflammatory activit/. Also some tural analysis of the product formed retains the car­ oxadiazolopyrimidines were reported6 to possess fun­ boethoxy group of and the cyano gicidal activity. In recent years, pyrimidine deriva­ group of the cyanoethyl acetate. This suggests th at th e tives have received significant attention owing to their requisite C-C-C funct ionality for the construction of diverse range of biological properties particularly be­ the pyrimidine ring uses onl y two carbon centers of 7 ing calcium channel blockers • 4-Amino-5- these and the third carbon being provided by oxopyrido[2,3-d]pyrimidine riboside was found to be the aldehydic function of the aldehydes employed. 8 very potent inhibitor of cancer cell profilation . The availability of the carboethoxy group at C-5 of The C5 position of pyrimidine nucleus is an attrac­ the pyrimidine rings helped us to think of exploring tive site for modification as it is located at the major the possible modi fications that can be made at thi s groove surface in the duplex form and will not di ­ position thereby forming modified bases of significant rectly inhibit the hydrogen bond in an A : T base structural importance. Incidentally, the carboethoxy 9 10 pair · . group of 1 was converted to its hydrazide deri vative The most general and widely employed route to 3, which furnishes better reaction site for the con­ involves the combination of a reagent struction of modified structural units. Thus, the hy­ containing the N-C-N skeleton with C-C-C unit. drazides of 1 were condensed with diverse cyclising These syntheses are typical examples of the bi s­ agents such as aromatic aldehydes, CS 2 to give nucleophile plus bis-electrophile method of construct­ pyrimidotriazoles 4 and pyrimidothiadiazoles 5 re­ ing heterocycles. Both the nitrogen atoms of the N-C­ spectively (Scheme 1). N reagent act as nucleophiles and both the terminal The structure-activity relationship study of carbon atoms of C-C-C reagents are electrophiles. pyrimidines reveals that N-alkyl derivati ves are more Urea, thiourea and guanidine are commonly used as potent towards the microorgani sms th an that of the PADHY et al.: SYNTHESIS OF PYRIMIDINE DERIVATIVES 911

CH3COCH2COEt + ArCHO+ CJl

X=O, S 2

Ar = Ar'= C6H5, m-N02C6H4, p-CIC6H4, p-N(CH3)2CsH4 A= C6H5, m-N02CsH4 Scheme I unsubstituted ones as they increase the toxicity of the molecules. Thus, the synthetic pyrimidines 4 were subjected to phenacylation with the implication that it will increase the potential of the molecules.

There are two sites available for the phenacylation 7 2 N 1- and N3- in those molecules. However, the Nrsite is preferred over the N 1-site as the N 3-proton is com­ 1 paratively more acidic than N 1, being flanked by a and aromatic nucleus. The question of formation of the mixed product was overruled on the basis that compound 6 is not only having the sharp melting points but also the CH3 peak in the 'H NMR is free from any NOE (Nuclear Overhauser 8 Effect). a. C 6 H5, X = 0, b . Ar = C 6 Hs. X = S Compound 2, which has an analogous nucleus as c. Ar= m-N02C 6H4, X=S, d . Ar = p -C IC 6H 4, X=O e. Ar= p-CIC 6 H 4, X=S, f. Ar= p-N(CH 3 ) 2 C 6 H4 , X=O uracil can therefore be named as uracil derivative, g . Ar= p-N(CH 3 bCsH•, X= S having active site N3-. The proton is being more acidic and therefore can undergo facile alkylation Scheme II with ethyl bromoacetate to give corresponding N 3 -~­ ethoxycarbonyl derivatives 7. The hydrazides of 7 A disquitening trend after 1950's has been the possess a dinucleophilic locus and thus in turn con­ emergence of more sinister type of fungal infections, dense with 1,2-diketones to give corresponding fused which are, to a large extent, inatrogenic. These are pyrimidinopyridazine derivatives 8 (Scheme II). associated with the use of broad-spectrum antibiotics, 912 INDIAN J. CHEM .. SEC B, APRIL 2003

corticosteroids, cytotoxic drugs indwelling characters 255°C; Found: C, 57.61; H, 3.01; N, 18 .3. Calcd for and implants and emergence of AIDS. Looking to the C11H7N30S: C, 57.64; H, 3.05; N, 18.34%. 2c: m.p. broad spectrum of biological activity, we screened 179°C; Found: C, 48. 15 ; H, 2. 16; N, 20.41. Calcd for some of these synthetic compounds against Staphyllo C1IH6N30 3S: C, 48.17; H, 2.1 8; N, 20.43%. 2d: m.p. coccous, E. coli and Candida albicmzs. It has been 278°C; Found: C, 53.3 L; H, 2.4; N, 16.93. Calcd for observed that compounds 6b, 6h and 6v are active C11 H6N 30 2CI: C, 53.33; H, 2.42; N. 16.96%; 2e: m.p. against Candida albicans, whereas only 6h is possess­ 252°C; Found: C, 50.07; H, 2.25; N, 15 .91. Calcd for ing significant activity. All these activities were com­ C IIH6N30SCI: C. 50.09; H, 2.27; N, 15.93%; 2f. m.p. pared with the standard drugs chloramphenicol and 238°C; Found: C, 60.9 1; H, 4.65; N, 21.86. Calcd for clotrimazole by measuring the zone of inhibition. C13H12N402: C, 60.93; H, 4.68; N, 2 1.87%; 2g: m.p. 2 15 °C; Found: C, 57.33; H, 4.39; N, 20.54. Calcd for Experimental Sections C1 3H1 2N40S: C, 57.35; H, 4.41; N, 20.58%. All the m.ps were measured and uncotTected. IR spectra were taken in Perkin-Elmer FT-IR spectropho­ Reaction of 1 with hydrazine hydrate: Synthesis tometer. 1H NMR was taken in 90MHz Perkin-Elmer of 3. To 1 (0. 1mol e) in ethanol (20mL) was added spectrophotometer. The microbial screening was done hydrazine hydrate (0. 1mol e) followed by the addition 11 employing cup-plate agar method . of a catalytic amount of cone. H 2 SO~ (5clrops). The Synthesis of 4-aryl-5-cal"lJOethoxy-6-methyl·2- mixture was refluxed for 2hr. Excess solvent was re­ pyrimidinone 1: General procedure. Urea (0.5 mole), moved and on cooling a solid was formed. The solid was crystall ised from ethanol to give 3. 3a: IR: ethyl acetoacetate (0.75mole) and aromatic aldehyde 1 1 (0.5 mole) were mixed in ethanol (25 mL). Catalytic 1570(C-N), 1650 (amide), 3350(NH) cm. ; H NMR amount of cone. HCI was added to the mixture, which (90mHz) : 82.5 (d,2H, NH 1-/2), 3.4 (s, C- H-CO), was then refluxed fo r 3hr. T he contents were kept in 5. 1 (s, CO-NH-CO), 4. 1 (t, CONHN), 7-8 (m. 5H, refrigerator overnight. The sol id separated out was ArH), m.p. 196°C, 3b: m.p. 195°C, 3c: m.p. 175°C, filtered off. The filtrate was further refluxed on a wa­ 3d: m.p. 190°C. ter bath for 1.5hr. On cooling a solid separated out Synthesis of triazolo-pyrimidinone derivative 4. was filtered and recrystalli zed from ethanol to give 1. To a solution of 3 (0. 1mo le) in acetic acid (20mL) a la: IR (v): I 570(C-N), 1650 (amide), 1730 (), pinch of ammonium acetate was added followed by 1 1 3350(NH) cm· ; H NMR (90MHz): 8 1.5 (s, CH3), the addition of aromatic aldehyde (0.1mole ). The mix­ 1.8 (t, COOCH2CH3), 2.5 (q, COOCH2CH3), 3.4 (s, ture was stirred for 2.4 hr at room temperature. The C-NH-CO), 5.4 (s, Ar-Nl-1-CO), 6.4 (s, Ar-CH), 7-8 mother liquor on neutralization wi Lh ammonia solu­ (m, 5H. ArH); m.p. 21.0°C (72%); Found: C, 64.59; tion gave a soli d, which was filtered and recrystailised H, 6.14; N, 10.73; Calcd for C ~ H 6 N 0 : C, 64.61; H, from ethanol (Table 1). 4b: IR: 1650 (amide), 1 1 2 3 1 1 6.14; N, 10.73%. 1b: m.p. 187°C (75 %); Found: C, 3350(NH) cm. ; H NMR (90MHz) : 8 I .4 (s, -CH3), 56.91; H, 4.96; N, 9.2. Calcd for C 14H15N20 3CI: C, 5.2 (s, C-NH-CO), 7-8 (m, 9H, ArH). 57.04; H, 5.09; N, 9.5%. 1c: m.p. 195°C (62%); Synthesis of pyrimidinothiadiazole 5. To a solu­ Found: C, 63.3; H, 6.84; N, 13 .81. Calcd for tion of KOH (0.1 5mole) in ethanol and heteroaroyl C1 6H21N30 3: C, 63.36; H, 6.93; N, 13 .86%. 1d: m.p. hydrazide (0. I 5mole) was added CS2 (0. 15mole). This 220°C (78%); Found: C, 54.95; H, 4.85; N, 13.65. mixture was diluted with ethanol and agitated for a pe­ Calcd for C14H1sN305: C, 55.08; H, 4.91; N, 13 .77%. riod of 12- l6hr. Jt was subsequently neutralized with Synthesis of 4-aryl-5-cyanopyrimidin-2, 4-dionc HCi and the precipitated solid was filtered, washed with water and recrystalized from ethanol. Sd . IR : 2: General procedure. To a mixture of urea (0.1 mole), 1 cyanoethyl acetate (0. 1mole ) and aryl aldehyde 1570(C-N), 1650 (amjcle), 2650(SH), 3350(NH) cm. ; 1H NMR (90MHz) : 81.4 (s,JH, CH ), 3.2 (s, 6H , (O.Imole) in ethanol , K2C03 was added and refluxed 3 for 7 hr on a water bath. On cooling the solid separated OCH3), 6.4 (s, ArCH), 7-8 (m, 3H, ArH). Sa: Oi l; Sb· out was filtered. The residue was dissolved in hot water m.p. 200°C; Found: C, 40.84; H, 3.38; N, 17.32. Calcd and filtered when hot. The filtrate was neutralised with for C1 3 H I IN ~ S 2 0CI: C, 40.93; H, 3.41; N, 17.36%. Sc: acetic acid and the solid precipitated out was filtered m.p. 2L5°C; Found: C, 39.59; H, 3.27; N, 20.96. Calcd and recrystallised from ethanol. 2a: m.p. 289°C; for CuHI1Ns03S2 : C, 39.64; H, 3.3; N, 21.02%. Sd : Found: C, 61.92: H, 3.25; N, 19.67. Calcd for m.p. l92°C; Found: C, 51.51 ; H, 5.51; N, 15.97. Calcd CI1H7N30 2: C, 6 1. 97; H, 3.28; N, 19.]1 %. 2b: m.p. for C1 sHI 6N40 3S2: C, 51.58; H, 4 .58; N, 16.04%. PADHY et a/. : SYNTHESIS OF PYRIMIDINE DERIY ATIVES 913

Table 1-Analytical data of 4-aryl-5-(2-aryl-1 ,3,4-triazolo)-6-methyl-1 ,2,3,4-tetrahydropyrimidin-2-ones (4)

Compd Ar Ar' m.p. Mol. formula Calcd (Found) No (DC) c H N 4a C6Hs m-N02C6H4 112 C,9 H,6N60 3 60.63 4.25 22.34 (60.6 4.19 22.3) 4b C6Hs p -C IC6H4 85 C,9 H,6NsOCI 62.38 4.37 19. 15 (62.33 4.3 19.1) 4c C6Hs p-N,N(CH3hC6H4 95 C21 H22N60 67.37 5.88 22.45 (67.3 5.85 22.4) 4d p -CIC6H4 m-N02C6H4 73 C19 H,sN60 3CI 55.54 3.65 20.46 (55.48 3.6 20.4) 4e p-CIC6H4 p-CIC6H4 52 C19 H15N50CI2 57.00 3.75 17 .5 (56.92 3.71 17 .45) 4f p-CIC6H4 p-N,N(CH3)2C6H4 Oil 4g p-N ,N(CH3hC6H4 m-N02C6H4 124 C21 H21N103 60.14 5.01 23.38 (60.1 4.97 23.3) 4h p-N,N(CH3hC6H4 p-CIC6H4 78 C21 H21N60CI 61.68 5.14 20.56 (61.6 5.1 20.5) 4i p-N,N(CH3hC6H4 p-N,N(CH3hC6H4 92 C23 H21 N10 66.18 6.47 23.5 (66.14 6.43 23.47) 4j m-N02C6H4 m-N02C6H4 86 C,9 H,sN10 s 54. 15 3.56 23.27 (54.1 3.53 23.2) 4k m-N02C6H4 p-CIC6H4 108 C19 H,sN60 3CI 55.54 3.65 20.46 (55.5 3.61 20.42) 41 m-N02C6H4 p-N,N(CH3)2C6H4 118 C21 H21N10 3 60.14 5.01 23.38 (60.09 4.97 23.35)

Reaction of pyrimidinones 4 with phenacyl crushed ice. The solid separated out was filtered and bromide: Synthesis of 6. To a solution of 4 (0.1mole) recrystallized from ethanol to give the desired prod­ 1 1 in , potassium carbonate was added followed uct. Sc: IR: 1650 (amide), 3350(NH) cm- ; H NMR by the addition of phenacyl bromide (0.1mole). The (90MHz) : 8 1.4 (s, -CH3), 3.4 (s, C-NH-CO), 6.1 (d, mixture was stirred for 2 hr at room temperature. Ex­ lH, ArCH), 3.1 (d, 1H, NCH), 6.8-8.5 (m, 15H, ArH). cess solvent was removed and the solid separated out Sa: m.p. 87°C; Found: C, 70.56; H, 3.67; N, 15 .23. was recrystallised from acetone (Table II). 6c: IR: Calcd for C27H 17 N50 3: C, 70.58; H, 3.70; N, 15 .25%. 1 1 1650 (amide), 1690 (-CO-), 3350(NH) cm- ; H NMR Sb: m.p. 72°C; Found: C, 68.19; H, 3.54; N, 14.71. (90MHz) : 8 1.4 (s, -CH3), 3.4 (s, C-NH-CO), 3.6 (s, - Calcd for C21H17Ns02S: C, 68.21; H, 3.57; N, COCH2), 7-8 (m, 9H, ArH). 14.73%. Sc: m.p. 78°C; Found: C, 62.28; H, 3.06; N, Reaction of 2 with ethyl bromoacetate: Synthe­ 16.11. Calcd for CnH,6N604S: C, 62.3; H, 3.07; N, sis of 7. To a solution of 2 (0.1 mole) in acetone, po­ 16.15 %. Sd: m.p. 96°C; Found: C, 65.63; H, 3.22; N, tassium carbonate was added. To this mixture ethyl 14.16. Calcd for C21H,6N50 3CI: C, 65.65; H, 3.24; N, bromoacetate (0.1mole) was added and the mixture 14.18%; Se: m.p. 68°C; Found: C, 63.56; H, 3.11 ; N, was refluxed for 6hr. On cooling the solid separated 13.71. Calcd for Cn H,6N50 2SCl: C, 63.59; H, 3.14; out was filtered and recrystallised from acetone. 7a: 1 1 N, 13 .73%; Sf: m.p. 85°C; Found: C, 69.29; H, 4.36; IR: 1650 (amide), 1730 (ester), 3350(NH) cm- ; H N, 16.71. Calcd for C29 H22N603: C, 69.32; H, 4.38; N, NMR (90MHz): 81.8 (t, -COOCH2CH3), 2.3 (s, 16.73%. CH2COOEt), 3.6 (t, -COOCH2), 7-88 (m, 5H, ArH). Synthesis of pyridazinopyrimidine derivatives S. Acknowledgement To a solution of hydrazides of 7 (0.1 mole) in sodium The authors like to thank the authorities of Ber­ ethoxide (prepared by dissolving 1g of sodium metal hampur University for providing fellowship to MB in 20 mL of ethanol), benzil (0.1mole) was added. and Director, NIST for providing facilities to carry The mixture was refluxed for 4hr and then poured into out the work. 914 INDIAN J. CHEM., SEC B, APRIL 2003

Table II- Analytical data of 6

Compd R Ar' Ar' m.p. (oC) Mol. formula Calcd % (Fou nd) No c H N 6a C6Hs C6Hs m-N02CoH4 165 C21 H22 N604 65.58 4.45 17.00 (65 .56) (4.4) ( 16.96) 6b m-N02C6H4 CoHs III-N02C6H4 89 C21 H2, N10o 60. 11 3.89 18 . 18 (60.09) (3 .85) ( 18.16) 6c CoHs CoHs p-CIC6H4 192 C21 H22 Ns0 2CI 67.0 1 4.55 14.47 (66.96) (4.5 1) (14.41) 6d m-N02C6H4 C6Hs p-CIC6H4 70 C21 H2,No04CI 61.3 3.97 15 .89 (6 1. 27) (3 .94) ( 15 .87) 6c C6Hs C6Hs p-N(CH 3)2C6H4 178 C29 H28 N602 70.73 5.69 17.07 (70.7) (5.67) (17.02) 6f III-N02C6H4 C6Hs p-N(CH.1hC6H4 72 C29 H21 N104 64.8 5.02 18.24 (64.76) (4.98) (18.2) 6g C6Hs p-CIC6H4 m-N02C6H4 182 C21 H2,N604CI 61.3 3.97 15.89 (61.27) (3.94) ( 15.86) 6h m-N02CoH4 p-CIC6H4 m-N02C6H4 80 C21 H2oN106CI 56.49 4.52 17.08 (56.45) (4.51) (17.02) 61 C6Hs p-CIC6H4 p-CIC6H4 6j m-NOzCoH4 p-CIC6H4 p-CIC6H4 85 C21H 2oNo04CI2 57.54 3.55 14.92 (57 .51) (3.52) ( 14.89) 6k C6Hs p-CIC6H4 p-N(CH3)2C6H4 116 C29 H21 N602CI 66.09 5.12 15 .95 (66.06) (5.08) ( 15.9) 61 m-N02C6H4 p-CIC6H4 p-N(CH3)2C6H4 89 C29 H26N70 4CI 60.89 4 ..54 17.14 (60.82) (4.5 I) ( 17.1) 6m C6Hs p-N(CH3)2C6H4 III-N02C6H4 142 C29 H21 N104 64.8 5.02 18.24 (64.76) (4.96) (18.2) 6n m-N02C6H4 p-N(CH.1hC6H4 m-N02C6H4 78 C29 H26 Nx06 59.79 4.46 19.24 (59.73) (4.43) ( 19.2) 6o C6Hs p-N(CH.1hC6H4 p-CIC6H4 OIL C21 H2, N60 4CI 6p m-N02C6H4 p-N(CH .1)2Col-14 p-CIC6H4 75 C29 H26 N104CI 60.89 4.54 17.14 (60.84) (4.5) ( 17.1 ) 6q C6Hs p-N(CH.1hC6H4 p-N(CH3)2C6H4 122 C31 H33 N10 2 69.53 6.16 18.3 1 (69.5) (6.15) ( 18.29) 6r III-N02C6H4 p-N(CH3h CoH4 p-N(CH.1hCoH4 80 C.11 H.12 Ns04 64.13 5.51 19.31 (64. I) (5.49) ( 19.28) 6s C6Hs m-N02C6H4 m-N02CoH4 142 C21 H2,N106 60.11 3.89 18. 18 (60.09) (3.85) ( 18.16) 6t m-N02C6H4 m-N02C6H4 m-N02C6H4 69 C21 H2o NsOx 55.47 3.42 19.17 (55.44) (3.4) ( 19.14) 6u CoH5 m-N02C6H4 p-CICoH4 167 C21 H2,N60 4CI 61.3 3.97 15. 89 (6 1. 28) (:_).94) (15.84) 6v m-N02C6 H4 m-N02C6 H4 p-CIC6H4 87 C21 Hzo N706CI 56.49 3.48 17.08 56.43 3.47 (17.05) 6w C6Hs m-N02CoH4 p-N(CH3)2C6 H4 96 C29 H21 N10 4 64.8 5.02 18.24 (64.74) (4.98) ( 18.2) 6x m-N02CoH4 111 -N02CoH4 p-N(CH3)2C6H4 77 C29 H26 Ns06 59.79 4.46 19.24 (59.73) (4.43) ( 19.2 1) PADHY et a/.: SYNTHESIS OF PYRIMIDINE DERIVATIVES 915

References 6. Ni zamuddin, Mishra Madhulika, Srivastava Manoj Kumar & I. Joule J & Smith G in Heterocyclic Chemistry (ELBS Low Kh an Mukhtar Hussain, Indian J Chem, 40B, 2001, 49. Price Ed itio'n, London), 1979, 126. 7. Atwal K S, Swanson B N, Unger S E, Floyd D M, Moreland 2. Wi erzehowski K L, Lifonskao E & Surger D, J Am Chem Soc, S, Hedberg A, O'reilly B C & Corrie J E T, J Med Ch em, 34, 87, 1965, 462. 1991, 806. 3. Garg H G & Prakash C, J Med Chem, 4, 1971, 175 . 8. Girardet J L, Gunii E, Ester C, Cieslak D, Pi etrzkowki Z & 4. Upadhaya D N & Ram Vi shnu J, Indian J Chem, 38B, 1999, Wang G, J Med Chem, 43, 2000, 3704. 173. 9. Cohen J S in Oligonucleotide-Antisense Inhibitors of Gene­ 5. Machon Z & Krystyna U, Acta Pol Chem, 42(b), 1985, 516; Expression (Mcmillan Press Ltd. London), 1989. Chem Abstr, I 06, 1986, 138388; Sarangan S & Somshekara S, 10. Beaucage S L & Iyer R P, Tetrahedron, 49, 1993, 6 123. J Indian Chem Soc, 4, 1976, 53; Shishoo C J, Path ak US, Ra­ II . Pharmacopoeia of India; Vol II ; 3'd Edn (Government of In ­ thod I S & Jain K S, Indian J Chem, 38B, 1999, 684. dia, Ministry of Health & Family Welfare) , 1985 A-90.