July, 1940
PREPARATION OF SOME
ALIPHATIC AMIDES
1309
The contents were rinsed from the bomb with chloro- the tube was passed 170 g. (1.12 moles) of 5-ethyl-2-(2hydroxyethy1)-pyridine a t a rate of one drop per second. form and fractionally distilled under reduced pressure The tFmperature during this time was'maintained a t 400through a 30-cm. Fenske-type columns using a trace of trinitrobenzene to inhibit polymerization. Products were 420'. An equal volume of chloroform was then added to 1137 g. of aldehyde-collidine, b. p. 73-75" (20 mm.), ~ O D the product, the water layer separated, and the organic 1.4970, 314 g. of 5-ethyl-2-vinylpyridine, b. p. 64-65' (3 layer dried over potassium carbonate. Fractional distillamm.), n a o D 1.5383, and 712 g. of 5-ethyl-2-(2-hydroxy- tion, after the addition of a trace of trinitrobenzene as a ethyl)-pyridine, b. p. 103" (1 mm.), 125" (3 mm.), ~ * O D polymerization inhibitor, gave 88 g. (6675, or 71 % accounting for recovery of 12.6 g. of starting material) of 5-ethyl1.5370. Combined yield, accounting for the recovered aldehyde-collidine, was 73%. 2-vinylpyridine, b. p. 95-97' (18 mni.); ~ * O D 1.5380. The picrate of 5-ethyl-2-(2-hydroxyethyl)-pyridine, B. By Dehydration with Potassium Hydroxide.-The apparatus and procedure was that described previously for crystallized from ethanol, melted at 101-102 '. AnaZ.8 Calcd. for CtaHlsN408: C, 47.37; H, 4.24. the preparation of 3 m e t h o ~ y s t y r e n e . ~From 160 g. (1.3z moles) of 5-ethyl-2-(2-hydroxyethyl)-pyridinea t 175 Found: C,47.55; H,4.18. and 17-18 mm. pressure was obtained 116.3 g. of crude disThe chloroplatinate was prepared by adding aqueous tillate. Redistillation through a 30-cm. Fenske-type platinum chloride solution to an alcoholic solution of th; c o l ~ m nusing , ~ a small amount (1: 1000) of trinitrobenzene product. Pink crystals were obtained, m. p. 165-167 as a polymerization inhibitor, gave 88.8 g. (63%) of 5(dec.). Prausnitz7. reported the chloroplatinate to be a cthyl-2-viriylpyridine, b. p. 95-97' (18 mm.); nzoD 1.5383. red crystalline compound, m. p. 159' (dec.). The picrate of the product, crystallized from water, I n the preparation paraformaldehyde (1 mole per mole of aldehyde-collidine is optimal) gives better results than melted a t 129.5-130.5'. Anal. Calcd. for CISHIINIO,: C, 49.72; H, 3.90. formalin. The use of ethanol as a solvent improves the 4 Found: C, 49.73; H, 3.90. yields, and it is most interesting that the addition of a trace of potassium persulfate (1% of the aldehyde-collidine) does so materially. Ammonium acetate, zinc chloSummary ride, sodium hydroxide, silver and potassium ferricyanide In the condensation' of ammonia with paraldeshowed no such catalytic effect. S-Ethyl-2-vinylpyridine.-The conversion of 5-ethyl-2- hyde the use of a large excess of ammonia leads (2-hydroxyethy1)-pyridine to 5-ethyl-2-vinylpyridine was t o 50-70y0 yields of aldehyde-collidine. achieved in good yield by catalytic dehydration, either The presence of a trace of potassium persulfate using alumina a t 400420' or, preferably, molten potasimprove9 the yields of 5-ethyl-2-(2-hydroxysium hydroxide a t 175". A. By Dehydration over Alumina.-A vertical 19-mm. ethyl)-pyridine in the condensation of aldehydePyrex tube heated by an electric furnace for a length of collidine with paraformaldehyde. twelve inches was packed with &mesh activated alumina (9) F r a n k , Adams, Allen, Gander a n d S m i t h , THIS J O U R N A L , 68, (Hydralo) and preheated a t 450' to drive off moisture. 1365 (1916). From a separatory funnel attached directly to the top of (8) hlicroaxialyses were carried o u t by Mr. Howard Clark.
URBANA, ILLINOIS
[ C O N ' I R I R U T I O S FROM 'I'IIE STERLING-M/'INl"ROP
RECEIVED MARCH 7, 1946
RESEARCH INSTITUTE]
Studies on the Willgerodt Reaction. 111. The Use of Simple Aliphatic Compounds BY JOHN A. KINGAND FREEMAN H. MCMILLAN Previous communications from these laboratories have shown that the Willgerodt reaction is by no means restricted to aryl alkyl ketones1 and have suggested a mechanism2 for the reaction. Although Willgerodt3 reported, in 1888, that if oenanthol were heated "a long time" a t 300" with yellow ammonium sulfide the product was oenanthylamide, no other successful application of the reaction t o an aliphatic compound had been published prior to last October. A t that time it was demonstrated by Cavalieri, Pattison and Carmack' that the reaction can be carried out successfully on purely aliphatic ketones. Experiments conducted in these laboratories similarly have shown that the reaction is applicable t o aliphatic ketones, alcohols, thiols and olefins. The present paper describes some of our results and indicates how all data thus far ( I ) King and McMillan, THIS JOURNAL, 68, 525 (1946). (2) King and McMillan, i b i d . , 68, 632 (1946). (3) Willgerodt, Bcr., 11, 534 (1888). (4) Cavalieri, Pattison and Carmack, (1846).
THISJOURNAL, 67, 1783
obtained are in accord with our previously proposed reaction mechanism. It seemed desirable t o select as a typical aliphatic ketone one which contained no tertiary alkyl group, in order that the similarity to an aromatic aliphatic ketone would be lessened. Methyl isobutyl ketone, to which we first applied the reaction, gave an 88% yield of isocaproamide. In order to determine whether the reaction would proceed satisfactorily when neither of the alkyl groups of the ketone contained a branched chain, the reaction was applied to methyl nonyl ketone. The product was undecanoamide. Willgerodt,s in his initial paper on the treatment of carbonyl compounds with yellow ammonium sulfide, found that a t room temperature acetone and ammonium polysulfide formed "duplodithioacetone," of unknown constitution. It was easily verified that when acetone and ammonium polysulfide were sealed in a pressure tube the separation of a heavy red oil occurred; ( 5 ) Willgerodt, Rrr
L
90, 2467 (1887).
however, when the rnixture was heated for four hours a t 210’ it yielded propionamide. By following Willgerodt’s direct ions, a pure sample of “duplodithioacetone” was prepared and when this was heated with ammonium polysulfide i t sirnilwly yielded propionamide. It was then of interest to extend the reaction to hi;lthiuroI;i.lit thc soltition at 20-2,i0 teii to twelve moles per hour nium brornide mas converted iiito t ~ i ~ ~ r o ~ ~ y l c a r l ~ i ~ t y l t l i i i i r o l i f hydrogeii s i i l t i d t . :oul(l he absorbed easily. When the nirim picrate which ineltc.d, after t w o rccry~t:illizniioris cii:irgc. of aintiioitia ~ ~ sa.turatctl 3 2 the solutioii was drained from aqueous alcohol, at 157". Oiic-half iiiolc of +In-(mioo u t : mid \veiglictl. tlieii otic-tciith its \\.eight of sulfur was heptaiie gave 1%; g. ( ( 2 ', yivltl: oi I)itriiiL(1 i)ici i f ( added and stirred irito solution. The reproducibility A n d Caletl. for C,Hl,S,S~CbH3S,,0::S, 7 . : )F l ' i ~ i i i ~ ~ l of the final solutioii is iiitlirated h v the three following S, 7.71. !Scminiicro Parr bonil) analysis i>y R I r . I' ;1 rcprcsent at ix.e aiid (coiiwcutive 1latches : one contained Deilerick (if t h r v !.a\mratories.! The tl~iut~~~iiiiiiii ;iic5.72 rnolcs r kilo of soliitioii of the complex ( SH4)2.&l.so, rate \vas decomposed hy steam distillatioii rrollt tlic. sccotid coiitai:!ed ,5.75 moles per kilo of solutiou of the of 10'; caustic. Tkii7ene rrtraction of the di.1 ill coniple\ C X I ~ 4 ~ ~ . n ,and S . 5 sthe third contained 5.65 moles tlic ptire mrrcnpt:m ivhich, a f t c r t x o fractio:i:;i I)er k i l o of i o l u t i o r l of t h e complex (KH4i.~.&.6~.Ap- tioils, \)oiled at 10' (7 n i i i i . ~and ~ {vcighed 10 g . i 11:' , \ it.lc! proxititately otic galloii of aninioniuin sulfide can be pre- froni the thitirotiium picrate, 2%'-; over-all yieiri fro, I IIC p i r e d in the toner i n a period of two to three hotirs. hroniidei. A n a l . Calcct. for C-HIGS: S, 24 2.h. I ' ~ u i i ~ 1 : S , 2t.O. (Semimicro Parr bomb niialysis b y l t r , 1'. I ; the experiments described were merely intended to s h o w %hether or not the reaction would proceed with t h e particular comiioui~d being tested. (10) Bentley and Perkin, 1.Chem. Soc., 7 3 , 6 5 (1808); h1:rrckwald (12) Robertson, J . Chrr". SOC.,115, 1220 (1919), gave 99" as the m. p. of undecanoamide. and Noldn. Bcr., 42, 1589 (1900). The latter authors reported the (13) Semimicro Kjeldahl analysis by Mr. H. E. Bauer of these m. p. as 119"; our material melted a t 115-117". J.aboratorh. (11) Obtained from Aromatic-s Division, Grneral Drug Co.
OLEFINICESTERS TO MALEIC ANHYDRIDES
July, 1946
The four Willgerodt reactions described above in detail may be considered as representative and typical of all those carried out. Therefore the remaining experiments are presented in tabular form, Table I1 consisting of the data on the various and diverse substances discussed in the text of this paper, and Table 111 consisting of the data on the series of simple mercaptans therein mentioned.
Summary A series of interrelated experiments has shown
1373
that not only aliphatic ketones, but also the corresponding a~coho~s, thiols and olefins undergo the Willgerodt to produce acid amides. The results of these experiments have further elucidated the course of the reaction additional support for the mechanism and previously proposed. RENSSELAER, NEWYORK RECEIVED FEBRUARY 13,1946
The Addition of Olefinic Esters to Maleic Anhydride BY JOHN ROSS, ARTHURI. GEBHART AND J. FRED GERECHT
There have been several reports in the patent and technical literature' where it is claimed that maleic anhydride reacts with mono-olefinic and non-conjugated poly-olefinic acids or esters a t temperatures of 200-250' to give addition compounds. The structure of the products obtained and the nature of addition reaction involved have not been established. We have examined the conditions under which maleic anhydride will unite with long chain mono-olefinic acids and esters and have determined the constitution of the major addition products of undecylenic and oleic esters. Mono-olefinic esters and maleic anhydride react a t temperatures of about 200-250' t o give good yields of the simple addition compound of one molecule of ester with one molecule of maleic anhydride and under these conditions only negligible amounts of higher molecular weight or polymeric material is formed. With undecylenic ester, maleic anhydride gives a product which consists mainly of stereomeric forms of structure I. The crude condensation
were obtained a solid acid m. p. 98.5' and a liquid acid fraction. Di-hydroxylation of the solid acid from the less soluble potassium salt gave a mixture of isomeric lactones of 4,5-dihydroxydodecane 1,2,12-tricarboxylic acid 111. The lactone form of I11 could not be oxidized with periodic acid in acid media. CHzCH (OH)C H ( 0 H ) (CHz)7COOH
I I
.--,
CHCOOH CHiCOOH
I11 CHzCOOH
I CHCOOH I
+ HOOC(CH&COOH
CHzCOOH
However, periodate oxidation of an alkaline solution of this lactone i. e., a solution of the trisodium salt of the dihydroxy tricarboxylic acid 111, proceeded quantitatively and by oxidation of the resulting aldehydes there was obtained azelaic and tricarballylic acids which demonstrated the structure of the addition product. CHFCHCHZ( CH2)rCOOCHa The solid acid ni. p. 98.5' which was thus shown to correspond to the ester 11, upon hydrogenation took up two atoms of hydrogen to give dodecane 1,2,12-tricarboxylic acid. The liquid tricarboxylic acid fraction remaining after removal of the less soluble potassium salt gave no dodecane 1,2,12-tricarboxylic acid after CHpC m o reduction and consequently could not have this I skeletal structure. This material therefore could CHzCH=CH (CHZ)+~OOCH, not be the geometrical stereomer of the solid acid I m. p. 98.5" although it had the same approximate CHCOOCH, analysis. It is therefore concluded that this kH2COOCHS fraction is probably an impure mixture of position I1 isomers of the solid acid and was not further product was converted to the trimethyl ester I1 examined. With methyl oleate a t a temperature of 200' which was distilled. The acids corresponding to this ester were separated into two fractions by maleic anhydride gives rise to an isomeric mixcrystallization of the potassium salts, from which ture of addition products formed by attachment of the maleic residue to COor C ~and O the remain(1) E. A. Bevan, Oil and Colour C h e w Assoc., 94, 1939 (1940); ing double bond shifting to the Cl&ll or c9-C~ C. A . , 94, 5960 (1940); E. T. Clocker, U. S. Patent 218,882-90 positions, respectively, of the octadecenoic acid (1940): C. A . , 94, 3846 (1940); W.G. Bickford, P. Krauczunasand chain. D . H.Wheeler, Oil attd Soa9, 19, 23 (1042).
