April 5, 1956 THESYNTHESIS OF ALIPHATICNITRO COMPOUNDS 1497
The Reaction of Ethyl Nitroacetate with Sodium Nitrite.- nitrite reaction. The ratio of masses 30 to 44 was found to A 200-1111. flask was equipped with a stirrer, a dropping be 0.303 for the nitroacetate reaction gases and 0.300 for the funnel, a thermometer and a condenser. The condenser nitrous oxide sample. exit was connected to two traps arranged in series and TABLEI cooled to ca. -70". The outlet of the second trap was attached to a 1500-ml. gas buret, filled with 20% aqueous GASEOUSPRODUCTS FORMED ON TREATMENTWITH NaNOz sodium chloride. The system was swept with carbon di- Ty)., oxide for 2 hours then 13.3 g. (0.1 mole) of ethyl nitroacetate Compound Method C. % Cot 5% Nx0 % Na in 51.9 g. of ethanol was placed in the flask and, with stir- OZNCH2COzEt Orsat 28 =!z 5 38.3 33.0 28.7 ring, a solution of 17.8 g. (0.25 mole) of 97% sodium nitrite Mass spec. 29 & 1" . .b 59.3 40.7 in 51.9 g. of water was added dropwise. Addition was in- 02NCH2COtEt terrupted after 30 minutes when about 0.1 mole of the so- OzNCH2CO~EtCOrsat 28 + 1 ..b 64.0 36.0 dium nitrite had been added; the reaction became exother- OzNCH~COzEtc Mass spec. 28 + 1 .b 65.1 34.9 mic with the liberation of much gas and exte;nal cooling BrCHZCOzEt Orsat 29 i 1 28.2 40.5 30.7 was needed to keep the temperature at 28 zk 5 . After 24 hours the evolution of gas had almost ceased; the remainder Except for 10 min. at 78". * Contacted for 24 hours with of the sodium nitrite was added but almost no additional gas 50% aqueous potassium hydroxide before analysis. e These was evolved. Gas evolution ceased altogether after a total two analyses are for the same sample of gas. of 31 hours when 2102 ml. (0.094 mole) had been collected The Lepercq Reaction.l*-In the early stages of this study (after correction to standard conditions). The gas evolved ethyl a-oximinopropionate, butyrate, valerate and caproate was colorless and odorless and no brown fumes were observed were prepared from the corresponding a-bromoesters in 71 when a sample was mixed with air; the cold traps had only to 85% yields by allowing 0.1 mole of the bromoester to re- traces of moisture. Thus hydrogen cyanide, nitrogen di- act with 0.25 mole of sodium nitrite in aqueous ethanol (50- oxide and nitrogen trioxide were absent, or present only in 55 weight per cent. ethanol) for 16 days. traces. Ethyl Nitritoacetate.-Ethyl glycolate (41.6 g., 0.4 mole, Samples of the gas were analyzed in an Orsat apparatus nm~1.4170) was treated with 39.3 g. (0.6 mole) of nitrosyl using absolute ethanol for absorption of the nitrous oxide. chloride in the presence of 50 g. (0.85 mole) of anhydrous Oxygen, carbon monoxide and nitric oxide were absent, or trimethylamine at 0' in a system protected from atmospheric present only in small amount but carbon dioxide (a correc- moisture. Anhydrous ether was added from time to time to tion having been made for the volume of COZinitially pres- keep the solution from becoming too viscous due to the pre- ent), nitrous oxiae and nitrogen (by difference) were present cipitation of trimethylammonium chloride. After the addi- in roughly equal volumes (Table I). In order to obtain a tion was completed, the mixture was stirred for another hour more direct identification of the nitrous oxide and nitrogen, and then filtered rapidly using anhydrous ether to aid in the samples were allowed to stand with 50% aqueous potassium transfer. Most of the ether was removed by distillation at hydroxide for 24 hours (samples so treated showed no carbon room temperature under reduced pressure; the residual dioxide by Orsat analysis). The carbon dioxide-free samples solution was dried over Drierite at 0 to 5" in the dark and were then dried with potassium hydroxide pellets and with fractionated. There was obtained 13.4 g. (39% yield) of Ascarite. Mass spectrometric measurements showed the ethyl nitritoacetate, b.p. 32-33' at 7 mm. and 118' at 760 significant masses to be 28 (nitrogen), 30 (nitrosyl ion) and mm. (micro-Emich), ZmD 1.4050, dz04 1.1148, d", 1.0947. 41 (nitrous oxide). Small masses were also detected at 29, Anal. Calcd. for C4H7OaiY: C, 36.09; H, 5.30; N, 10.52. 31,32,40,45 and 46; these are thought to have been due to Found: C, 36.07; H, 5.17; h-, 10.62. the natural occurrence of heavy nitrogen atoms and also to Ethyl nitritoacetate proves to be a pale, yellow-green slight contamination by air. In order to establish that the liquid which is water soluble and which hydrolyzes within a mass 30 species was due to the presence of nitrous oxide, few seconds at room temperature to give ethyl glycolate and presumably because of the formation of nitrosyl ion (NO+), nitrous acid. It is soluble in ethanol, acetone, ether, ben- a sample of nitrous oxide (Matheson) was treated with po- zene and petroleum ether. tassium hydroxide solution, dried and analyzed in the same m3nner as gas samples from the ethyl nitroacetate-sodium LAFAYETTE,ISDIANA
[CONTRIBUTIONFROM THE DEPARTMENTOF CHEMISTRY,PURDUE UNIVERSITY] A New Method for the Synthesis of Aliphatic Nitro Compounds',2 BY NATHANKORNBLUM, HAROLD 0. LARSON,ROBERT K. BLACKWOOD,DAVID D. MOOBERRY,EUGENE P. OLIVETOAND GALENE. GRAHAM RECEIVEDSEPTEMBER 8, 1955
A simple new synthesis of primary and secondary nitro compounds which involves treating alkyl halides with sodium nitrite in dimethylformamide is described; 5542% yields of pure nitro compounds are obtained.
To date the principal method of preparing nitro- only for the synthesis of primary nitroparaffins. paraffins has been the reaction of an alkyl halide With secondary halides the yields of nitroparaffins with silver nitrite.a A recent study has demon- are about 15y0 while with tertiary halides they fall strated, however, that this reaction is really useful to 0-5%.* A synthesis developed by Iffland and (1) Paper XI1 in the series, "The Chemistry of Aliphatic and Ali- his co-workers, which involves the conversion of cyclic Nitrocompounds." A preliminary account of this work ap- ketones into secondary nitroparaffins, is extremely peared in Chemistry and Induslry, 443 (1955). valuable in certain instances, e.g., the synthesis of (2) This research was supported, in part, by grants from The Ex- nitrocyclobutane, but it cannot be regarded as a plosives Department of E. I. du Pont de Nemours and Co.. and, in part, by the United States Air Force under Contract No. AF 18(600)- method of general ~tility.~ 310 monitored by the Office of Scientific Research, Air Research and (4) N. Kornblum. B. Taub and H. E. Ungnade, Tars JOURNAL, 76, Development Command. 3209 (1954); N. Kornblum, R. A. Smiley, H. E. Ungnade, A. M. (3) Industrially, of course, the vapor phase nitration process due to White, B. Taub and S. A. Herbert, ibrd., 77, 5528 (1955). Hass is employed on a large scale for the preparation of nitromethane, (5) D. C. Iffland, G. X. Criner, M. Koral, F. J. Lotspeicb, 2. B. nitroethane and the two nitropropanes. But despite its great com- Papanastassiou and S. M. White, ibid., 76, 4044 (1953); D. C. If- mercial importance this cannot be regarded as a laboratory procedure, Band and G. X. Criner, ibid., 71, 4017 (1953); D. C. Iffland and Teh-Fu especially since curnplcs mixtures of products are formed. Yen, ibid., 76, 4083 (1964). .% rather obvious way of synthesizing nitroparaf- X second reason for using DMF is that the reac- fins would appear to be the reaction of an alkyl hal- tion of alkali nitrites with alkyl halides is exception- ide with sodium nitrite ally fast in this inediuiri.",'? This great speed of R--S + SaSO. --+ R-SO: + SaS reaction in DXF inzil;es it 1)imihle to ininimize a Howi-er, it is widely acceptctl that the reaction of side reaction (l), whnse esistciice 1r:is lxcn estab- dkyl halides with alkali metal nitrites produces ni- lished recentlyI3 trite esters rather than nitro cotnpounds.6 R' R' To add to the confusion, there is an old and well known preparatiim of nitromethane (35-3STh yield) in which the sodium salt of chloroacetic acid is treated with sntlitini nitrite after which the un- R' stable a-nitroncetic acid is tlecarbo~ylated.~IVhat is not so well known, however, is that this method, which is clue to Kolbe,is worthless for the prepara- s0 tion of higher nitroparatlins.3 Firinlly, the reaction R = alkyl; I<' = :ilkyl or Iiytlrogcii of sulfonate esters with alkali metal nitritcs has been reported, tiine and again, to be without merit Even in DlIF socliuiri nitrite has ;I ixtlier liiiiitetl :IS :L means of synthesizing nitro par nil in^.^ solubility arid this pr rits realization of the rc;ic- The present investigation shows that, contrary tion of nitrite ion with :in xIIiy1 h:iIitIc :it r:itrb to general opinion, the reactioti of sotliuni nitrite which would fx, Liirticil):i.te(l fro111 the kixetics ill with alkyl halides is a simple and effective way of dilute solution. I1 Solietheless, the reaction of :L obtaining nitro coilipountls. The usefulness of primary broinidc or iotlitle Jvith so:liulil nitrite at this reaction can be gauged from the yields of pure room teinperatttre is so much faster than the coni- alip1i:itic and alicyclic nitro compounds given in peting process that merely working up the re:iction 'rLlbiert niisture proiiiptly prevents ititrusioii b!. the reac- TAIILEI tion of eq. 1. 117th sccontlan- broinic!es :itid iotliclcs the rex- 12r.~c11o:. ,4I.KTL. ASD CYCLOALKTI,HALIIIES IVITII or tion of eq. 1 ~voultlbecome a svrious coinpetitor in Son~carSITKI.I.E Yield, 7 the absence of se.,-eral siiiiplc tlevices. The atltli- Halide Sitro comp
II. Vrll I, John nile>- and Sons, Inc.,
1: KauFier and C. Pumeronz,
(10, .~L)I)I.DIY mooP.-lIr. D. E. Hardirs of this laboratory has noti ioiin As will be seen from Table I, alkyl bromides and if it is added, the only effect is to halve the reaction time. The following procedure is typical of that used with all pri- iodides are equally useful for the preparation of pri- mary halides except benzyl bromide (see below). mary and secondary nitroparaffins. In contrast, The Preparation of 1-Nitrooctane from 1-Bromooctane.- alkyl chlorides react too slowly to be useful. I-Bromooctane (58 g., 0.30 molc) was poured into a stirred The reactions employing 1- and 2-bromooctane mixture of 600 ml. of DMF and 36 g. of sodium nitrite (0.52 mole) immersed in a water-bath maintained at room have been found to be first order in halide and first temperature?'; stirring was continued for 0 hours Tlie order in nitrite ion." It is not surprising, then, reaction mixture was then poured into 1.5 1. of ice-water that this bimolecular displacement process fails layered over with 100 ml. of petroleum ether (b.p. 35-37'). with t-butyl bromide, t-butyl chloride, cyclohexyl The aqueous phase was extracted four more times with 100- bromide and cyclohexyl iodide. Instead of nitro ml. portions of petroleum ether after which the extracts were washed with four 75-ml. portions of kiter and dried compounds, isobutylene and cyclohexene are ob- over anhydrous magnesium sulfate. The petroleum ether tained. l6 was removed by distillation under reduced pressure through Sulfonate esters may also be employed; n-octyl the columnso; heat was supplied by a bath whose tcmpera- tosylate, for example, gives 1-nitrooctane in 43- ture was gradually raised to ca. 65". Rectificationznof the residue yielded 13.6 g. (29Tc) of 1-octyl nitrite (b.p. 37" 4G7, yield." The use of sulfonates would, of (2 mm.), ffzo~1.4127; lit. values'.' b.p. 56" (9 mm.), nzOD course, be advantageous when dealing with alcohols 1.4127), 2.8 g. of interfractions, and 28.2 g. (GO'%) of 1- which arc subject to rearrangement on conversion nitrooctane (h.p. 60" (1 mm.), ~:OD 1.4321; cf. T:ible 11). in to halides. \Vith the iodides, the proc~durewas modiiied slightly iii that the petroleum ether extracts were washcd with two 75- Finally it should be pointed out that the reaction ml. portions of lOy0 aqueous sodium thiosulfate (to remove of alkyl halides with sodium nitrite in DMF is car- small amounts of free iodine) and then with two 75-ml. ried out under very mild conditions. The reaction portions of water. temperature is niaintained at or close to 25' except The Preparation of Phenylnitromethane from Benzyl Bromide.-In the special case of benzyl bromide it was for a few instances in which it is lowered to -20 to necessary to operate at -20 to -15" and to add urea. At - 15' (cf. Experimental). room temperature no phenylnitromethane was obtained, The only product isolated, benzoic acid (25% yield), was. Experimental '8 presumably, formed oia the nitrolic acid. Reagents.-Dimethylformamide, du Pont technical grade, Benzyl bromide (51.3 g., 0.30 mole) was poured into a is essentially anhydrous and in a number of experiments stirred mixture of 600 ml. of DMF, 36 g. of sodium nitrite was used directly. In a number of instances the DbIF was (0.52 mole) and 40 g. of ureamaintainedat -20 to -15°.zc dried by allowing it to stand over calcium hydride. Al- After five hours the reaction mixture was worked up as in though no attempt W:IS made to study the influence of water the I-nitrooctane preparation except that 700 ml. of diethyl on the reaction, it does not appear that rigorously anhy- ether was used for extraction. Rectificationznyielded 13.1 drous conditions are necessary. Analytical grade sodium g. (33%) of crude benzyl nitrite (b.p. 44' (5 mm.), n7'D nitrite, dried at 115', was used. The urea was dried at 1.5010-1.5024), 1.7 g. of interfractions and 22.1 g. (MG)of 105' for several hours. Ringwood Technical Grade phloro- phenylnitromethnne (b.p. 76" (2 niin.), tzsO~1.531ii; 6. glucinol dihydrate was rendered anhydrous by heating for Table TI). three hours at llOo.l9 (b) Secondary Nitro Compounds.-In reactions employ- The alkyl halides were carefully rectifiedz0and only middle ing open-chain secondary iodides, addition of urea is sulli- cuts of constant 12% and b.p. were used. Except in the cient to prevent the side reaction of cq. 1. If urei is not case of cycloheptyl bromide the ~?ODvalues were identical added there is a ca. 5yc drop in yield, presumably because with those in the literature. Our cycloheptyl bromide was the reaction must then be run ca. 2.5 times longer. ohtained from the alcohol in 87% yield, b.p. 50" (3 mm.), With secondary open-chain and alicyclic bromides, and n?"~1.5049; Vogelzl reports ?z?OD 1.4991 and Zelinsky22 also cyclopentyl and cycloheptyl iodides, it becomes de- nzo~1.49%. ilnal. Calcd. for C:FIl:,Br: C, 47.49; H, sirable to add a nitrite ester scavenger such as phloroglucinol. 7.40. Found: C, 17.30,47.48; H, 7.39, 7.48. For example, when 2-octyl bromide reacts with sodiutn nitrite The only iic\v intlide is l-iodo-~-~~licnylpropane(73Tc in DMF-urea, the yield rises to a maximum in the range 13- yield), b.p. 98' (.'$ niin.), nznD 1.5SX). .3trnl. C:ilcd. for 16 hours and then falls; but even after 25 hmrs uiireacted CsHinI: C, 43.92; II, 4.51. Fourid: C, 43.04; H, 4.58. 2-octyl bromide remains. By addiiig phloroglucinol, how- n-Octyl tosylate was preparctl from n-octyl alcohol and tosyl ever, the yield of 2-nitroGctane, after a 45-hour reaction chloride hy the inetliod of I)r:iiion.zal and K1:imannz3: time, is 587,. The other product, instead of being 2-octyl b.p. 170" (0.8 mm.), U?OD 1.494Ci; lit.23 b.p. 167-168" nitrite, is 2-octano!, presuniably a by-product of the nitro- (0.6 mm.), n% 1.4946. sation of phloroglucinol. (a) Primary Nitro Compounds.-IVhen priin:irv bromides IVhen a nitrite ester scavenger is added to these systems, are used a readon time of sis hours is needed; ivith primary excessive reaction time is no longer critical The only re- iodides the reaction time is '7.5 hours. Urea is not needed; quirement is that sufficient time he given for the halide to react completely. Urea is employed onl!' for the convenience (16) In a recent paper, de la Mare, Hughes, Ingold and Pocker [J. of reducing the reaction time. Chem. Soc., 2930 (19,74)l claim that the reaction of I-butyl bromide with The Preparation of 4-Nitroheptane from 4-1odoheptane.- nitrite ions (supplied as either tetraethyl- or tetrametliyl-ammonium This was identical to the preparation of 1-nitroijctane from nitrite) gave f-nitrobutane and I-hutyl nitrite. Since it is reported I-bromoC-tane, except that (a) 40 g. of urea (0.67 mole) was that nitromethnne is used as the solvent, and since it is admitted that added to the sodium nitrite-DhlF mixture before atltlition dehydrohnlogenation ucciirs, it would, among other things, be of rnme of the 4-iodoheptane (,fj7.8 g., 0.30 mole), (11) the reaction than passing interest to know how these nutliors isolated I-nitrobutane time mas 5.6 hr. and (c) the petroleum ether extract5 were [rum such ail untidy iitiiiition-or e\-en managed to detect it. washed with aqueous lOyc sodium thiosulfate arid then (17) Conceivxbly the iise of ~,hluroglucinul will prrxluce a sig- water. RectificationZ5,*0yie!ded 10.9 g. (25%) of 4-heptyl nificnnt incre~sein the yield. nitrite (b.p. 44'' (18 mm.), ?Z?OD 1.4039) and 26.4 g. ((317;) of (IS) .4nalyses are by ChILraith Ilicroaniilytical Laboratories, Knoxville, Tenn., and by Dr. C. S. Yeh and 111s. S. L. Margerum, (24) This reaction is mildly eyuthermic. Also. since :ilkyl nitrites Purdue Unii ersity. are photochemically unstable 'tiorswell and Silk crmiin, Inf. Eiic (10) IVe are indebted to thP Rinpvood Chemical Co., Ringwood, Ill,, Chem., Anal. Ed., 13, .%5 (lg! ; in this, and subsequent oi~cratiuns, for a generous gift of phloroglucinol. exposure to strong light is avo) !r 4-nitroheptane (b.p. 59" (8 mm.), nZo~1.4219; cf. Table a",nND 1.4463) gave 2.0 g. (64%) of the derivative, m.p. 11). 117"; mixed m.p. 117'. In additiori, 5.8 g. (9%) of cyclo- 2-Nitrooctane was prepared from 2-iodooctane by the hexyl iodide was recovered. There was no detcctahlc same procedure, except that the reaction time was 4 hr. amount of nitrocyclohexane. The Preparation of 2-NitroSctane from 2-Bmo6ctane .- (b) The reaction of cyclohexyl bromide was coriducted The procedure used to prepare 1-nitrooctane from l-bromo- as for cyclohexyl iodide. After 21 days it \vas only 807, octane was followed except that (a) 40 g. of urea and 40 g. complete and on working up the dark red solution a 127, of anhydrous phloroglucinol (0.3 mole) were added to the yield of cyclohesene (b.p. 83", ~z*OD 1.4458-1.4462) VVL~ stirred DMF-sodium nitrite mixture and (bf-the reaction isolated. In addition a 15y0 recovery of cyclohexyl bromide time was 45 hr. RectificationM yielded 15.0 g. (38%) of 2- was made. octanol (b.p. 45' (1 mm.), Z~D1.4262; m.p. of the phthal- The Reaction of t-Butyl Bromide (and Chloride) with ate half-ester 55", mixed m.p. with known phthalate half- Sodium Nitrite.--ja) /-But\-] bromide (41 E., 0.3 molc, ester 55") and 27.6 g. (58%) of 2-nitrooctane (b.p. 67" (3 was treated with sodium nitrlte in DhIF as described for 4- mm.), Z~D1.4280; cf Table 11). iodoheptane, provision being made to trap isobutylene. 4-Nitroheptane was obtained from 4-bromoheptane hy After 24 hours at room temperature there was obtainwl this procedure (reaction time 60 hours). The urea-phloro- 12.3 g. (737,) of a liquid having b.p. -5"; lit. value for is(>- glucinol procedu-e was also used to prepare nitrocyclopen- butylene b.p. -;'.*: \\'hen allowed to evaporate into :I tane and nitrocycloheptane from the bromides, the reaction solution of bromine in carbon tetrachloride it decolorizctl times being 42 and 54 hours, respectively. Finally, even the solution. Ii'hen the esperiment was repeated at 0" fiir though this urea-phloroglucinol procedure was employed 18 hours, 11.5 g. (i'Oyoyield) of isobutylene, b.p. -(i5 to convert iodocyclopentane and iodocycloheptane to the was isolated. It decolorizcd bromine. nitro compounds, the reaction times were those required (b) The reaction of I-butyl chloride (38 g., 0.3 rn(~le) for secondary iodides, 5 and 6 hours, respectively (cf. Tables was carried out at 0' for six days. The only pruduct is)- I and 11). lated was isobutylene (10.8 g., 65yo yicld). It hnd b.p. Relevant data for the nitroparafins obtained in this study - 4.5', and decolorized bromine. are listed in Table 11. All dissolve completel!., but not at The Effect of the Solvent on the Reaction of I-Iodooctane once, in 10% aqueous alkali. In the case of 4-nitroheptanc with Alkali Nitrites.-The reactions were cc~nducted by shaking for ca. 2 hours is required to effect complete si~lu- adding 0.01) mole of the nitrite (4.6 g of LiSO?, 6.2 g. nf tloll. SaS02, 7.6 g. of KS02) and 0.05 mole (12 g.) of I-imIo- octane to about 90 ml. of the anhydrous solvent. The niis- TABLEI1 tures were allowed to stand, stoppered, in the da-k at rami PHYSICALCOXSTANTS OF SITROCo~~orsns temperature for 36 hours. At 8-hr. interval>a5-ml. sample I.iterati!re was withdrawn and tested for nitrite ion, iodide ion and B.P., BP. nitroparaffin. Compound OC. Llm. n20~ OC. llrn 112~~ The test for nitrite consisted in adding a crystal of potas- I-Sitroheptane 08 2 1 4284 04 3' 1 .4?83' sium iodide to about 2 ml. of the solution and acidifying with 1-Sitrooctane GO 1 1 4324 72 3p I 132Y 10% nitric acid. A positive test was indicated by the libera- I -Titrodecanen 1Oi 2 1 4391 tion of iodine and was taken to mean the alkali nitrite vas 1 -SItro-3-phenyl- soluble. I-Xitrooctane was detected by use of the Ilavidson propaneb 123 4 I ,5222 test . I'hrnylnitrornethane it7 2 1 531n 78 1' 1 5315'' All three nitrites are soluble in DLlF and ethylene glycol 2 Sitrouctnne I:; R 1 BO cili ?c I mne and in each nitroparaffin formitiori occurs. In etliand, .l-Sitri,hept,ine ,ill s 1 -1219 90 ?.io 1.i200'~Q methanol, acetone, 1,2-dimetliosyetliane, and pyridine lith- Titrocyclopentnoe .5'3 10 1.1530 RO .IOa I. 1516-',0 ium nitrite is soluble and a reaction occurs with the formatirlii Titrnci.cl,ltieptaoe 70 1 j I 1723 11-1 200 I 4729 of nitro compound; sodium and potassium nitrite are iit- soluble in these solvents and no reaction occurs. All three a .4?102 C:\lcd. for ClnH?ISO:: C, 64.12: H, 11.81; nitrites are insoluble in diethyl ether, acctonitrile, dioxanc~, S, 7.48. Fnund: C, 64.42; tr. 11.24; S, 7.66. ' .-lnui. and tetrahydrofuran and no reaction occurs. \Vith iv.it(.r Calcd. fnr CsH1:SO:: C, 65.43; H, 6.71; S,8 4S. Found: C, 63.3s; 6.88; 8.76. Ref. 4a. S. Fornblum, as a solvent the nitrites are soluble hut the halitli i- ill- H, S, soluble and again no reaction occurs. R. A. Smile?;, R. 6.Blackwood and D. C. Iffland, THIS The foregoing d.it:i were cnnfirmctl :inti e\tcniIi (1 1)). pre- TOVRSAL, 77, 6269 (1955'1. e Ref. 4b. ' nZ5~.Q Ref. 5. 11. Stone, Ph.D. Thesis, Ohio State University, l'J5il. TABLE111 Nitrite Esters.-T\ro new esters were produced as by- EFFECTOF SOI.VEUTos riir KI .\c IIUS OF l-Ior:nijcr.~s~ products of this synthesis of nitroparaffins: (1 i 11-decyl \\'I1 I1 A1.K \1.1 SIrRITES" nitrite, b.p. 9.5' (4 mm.j, 12'10~1 4747. R77nl. Gilcd. for CinH?iNO?: 7.48. Found: 7.40. (2) r-Phenyl-71- Unreacted S, S, Reaction Sitro, Sitrite, halide, I.iSO? propyl nitrite, b.p. 56' (1 mm.), ~I?"D 1.4979. Anal. Solvent time, hr Fc c, c-,c c Calcd. for C~HIINO?:N, 8.48. Found: S,8.62. LiSOz Use of Sulfonate Esters.-In the case of u-octyl tosylate, n-butyl tosylate and n-butyl methanesulfonate the procedure Dm 2;i 5; 2ti .. was identical to that for 1-bromooctnne, except th:it 40 g. of l (20) N. Kharasch, H. I.. R'ehrmeister and H. Tigerman, THIS JOCHSAI., 69, lF12 :l917]. April 5, 1956 ALIPHATIC NITRO COMPOUNDS WIT11 NITRITE ESTERS 1501 parative scale experiments. A mixture of 48 g. (0.20 mole) TABLEIV of 1-iodooctane, 24.2 g. (0.35 mole) of sodium nitrite (or 18.6 g. of lithium nitrite), and 250 ml. of the solvent mas “SOLUBILITY” OF NITRITES 1!4 DMF stirred at room temperature (or higher if noted). The Composition of undissolved solid was isolated by filtration, washed, dried, “solvent” Grams of and weighed. The filtrate was dried and rectified. In this Kitrite DlIF, ml. Urea, g. nitrite dissolved way the data of Table I11 were obtained. SaKOz 100 ... 1.88 The Influence of Urea on the “Solubility” of Alkali SaS02 100 4.35 4.41 Nitrites in DMF.-The “solubility” of sodium and potas- sium nitrite in DMF-urea solutions was determined by SaSO2 100 8.7 7.6 placing 10 g. of the alkali nitrite in 100 ml. of DMF contain- SaS02 100 19.4 7.27 ing varying amounts of urea. The mixtures were sealed, KSO? 100 .. 0.64 shaken for 24 hours at room temperature, the undissolved KS02 100 7.1 3.49 nitrite isolated by filtration, washed with anhydrous ether, dried and then weighed. LAPAYETTE,ISDIANA [cUSTRItjU?IOS FROM THE DEPARTMENT OF CHEMISI’RV, PURDUE UNIVBRSITYj The Reaction of Aliphatic Nitro Compounds with Nitrite Esters1r2 BY NATHAN RORNBLUhI, ROBERTK. BLACKWOOD ’\SD DAVIDD. bfOOBERRY RECEIVEDSEPTEMBER 9, 1955 Although primary nitroparaffins, secondary nitroparaffins and a-nitroesters are incrt toward nitrite esters, the joint action of a nitrite ester and sodium nitrite destroys the nitro compound. Primary nitro compounds give the carboxylic acid, secondary nitroparaffins yield ketones and a-nitroesters are converted to a-oxirninoesters. The course of these reactions is described. In the preceding paper of this series3it was found ate in 22 hours, ethyl a-oximinopropionate being that if a nitroparaffin, an alky1,nitrite and sodium formed. nitrite are allowed to stand at room temperature, Thus, for reaction to occur, all three reagents- the nitro compound is destroyed. The nature of the nitro compound, the alkyl nitrite and sodium the destructive process is the subject of the present nitrite-are needed. It is also necessary to have a communication. hydrogen atom on the carbon holding the nitro AS shown in Table I, when 1-nitrooctane is group as is shown by the failure of ethyl a-nitro- treated with sodium nitrite it is quantitatively re- isobutyrate (I) to react. From these facts, and the covered (expt. 1 to 3). Nor is there any reaction CH, when 1-nitrooctane is exposed to nitrite esters I (expt. 4 and 5). In contrast, when 1-nitrooctane CH3-C-COOCyH5 is exposed to the combined influence of sodium ni- I trite and an alkyl nitrite it is converted into ca- SO2 I prylic acid (expt. 6 to 9). data which follow, it is apparent that the reaction Table IB summarizes a series of experiments us- proceeds first to give nitrosated nitro compounds ing %nitrooctane. Here again the nitro compound (111) which, being unstable, break down to form is completely stable toward either sodium nitrite or the products isolated. As will be seen, the nitrite alkyl nitrites but is destroyed by their joint influ- ion simply functions as a base.j ence, Zoctanone being produced. In Table IC are recorded the data of experiments R’ in\.ol\ring ethyl a-nitropropionate. After 24 hours contact with sodiutn nitrite the cr-nitroester is re- covered in 93% yield4 (expt. 17). And after 45 flours there is no reaction between the a-nitroester Llnci n-propyl nitrite (expt. 19). But treatment \\-ith both sodium nitrite and n-propyl nitrite results ill colnplete destruction of the ethyl cr-nitropropion- , P.li,cr x-11 in the Series “The Chemistry of Aliphatic and Ali- c?clic Sstro Compounds.” 2) This research was supported, in part, by grants from The I P;\plusives Department of E. I. du Pout de Nemours and Co., and, in SO part, by the United States Air Force under Contract KO.AF 18 (600)- 111 310.~ monitored by the Oflice of Scientific Research, Air Research and Development Command. R”0- + HXO: +R”OH + SO?- (3) (3) N. Kornblum. H. 0. Larson, R. K. Blackwood, D. D. Mooberry, E. P. Oliveto and G. E. Graham, THISJOURNAL, 78, 1497 (1956). The reactions of I11 vary with the nature of tlic (4) Given 168 hours in which to act, sodium nitrite alone is able to substituents. When R = alkyl and R’ = hydro- destrvy a perceptible arnottnt of the a-nitroester (expt. IS). This is (5) Although nitrosation of nitroparallins by nitrite esters has under.;tandalile since n tiitrirr5trrs are distinctly more acidic than nitro- y:,r.r11ii,4, ~t is iritere.;ting to tli.rt the cctnver4on of an a-nitro- apparently not heen reported Ijrevioii.;l) (~iiewcruld Il;ive aiitir~l)atcd that, in the presence of a \trc,rig Iuse, c.R., etilmidc ion. iillroutl<~i) c.trr in,tllr a-o~ittiit~i~~~t~rIIY the agency of vi