Patented Feb. 20, 1945 2,369,919 U NITED STATES PATENT OFFICE j _ 2,369,919 KETOETHENONES AND rnoonss 'rnnanroa John Carl Sauer, Wilmington, Del., assignor to E. I. du Pont de Nemours & Company, Wilming ton, Del.. a corporation of Delaware No Drawing. Application October 13, 1938, Serial No. 234,843 ' 2 Claims. (Cl. 260-550) This invention relates to organic compounds ployed or in 30 minutes when the reaction is car ried out in re?uxing benzene or xylene with a and more particularly to certain disubstituted trialkylamine such as triethylamine. Higher ethenones, i. e., ketoethenones. Numerous investigations into the dehydrohalo - temperatures promote a more rapid reaction. A genation of primary acid halides,3i. e., those in test which may be applied to determine the end which .the acid halide group ' point is to withdraw a sample of t ev reaction mixture, ?lter it, add a small amount of amine to the ?ltrate, and boil- If no precipitate forms, (H) . -o-x the reaction is substantially complete. The higher substituted ethenones are conveniently (X being a halogen) is attached to a methylene puri?ed by recrystallization, and distillation is group, have been made, but there is no record usually unnecessary. - of the preparation of low melting dehydrohalo The lower acyl halides such as propanoyl chlo= genation products of monosubstituted ethanoyl ride are very reactive towards tertiary aliphatic halides. ' ‘ I 15 amines and are best dehydrohalogenated under This invention has as an object the prepara re?ux by adding the amine to the acyl halide tion of low melting intermolecular dehydrohalo solution (or vice versa) just fast enough to keep genation products of primary acid halides. A the solvent gently re?uxing when low boiling further object is the provision of a process there solvents such as diethyl ether are employed. for. Another object is the preparation of inter 20 With high boiling solvents such as dichloroben mediates for dyes and other useful organic chem zene, any suitable and convenient rate of addi icals. Qther objects will appear hereinafter. tion of the one reactant to the other may be These objects are accomplished by the follow employed. The lower acyl halides as a rule are ing invention which comprises reacting a tertiary completely dehydrohalogenated with trimethyl aliphatic amine free from active hydrogen under 25 amine within a few minutes at room tempera anhydrous conditions with a primary monoacyl tures. ' halide R—CH2—CO—X, where X is a halogen The more detailed practice of the invention is and R is a monovalent organic radical‘which, illustrated by the following examples, wherein at temperatures up‘to 170° C., is chemically inert parts given are by weight unless otherwise stated. to tertiary amines, acyl halides, and ethenones, 30 There are of course many forms of the invention and isolating, also under anhydrous conditions, other than these speci?c embodiments. the resulting intermolecular dehydrohalogena tion product, i. e., the disubstituted ethenone.v EXAMPLE ,I v The nature of the suitable amines and acid hal Dodecdnoyldecylethenone ides is more precisely explained hereinafter. 35 The reaction is carried out in the case of the C11H2sCOC(C1aH21)=@Q higher acid halides, i. e. of at least eight carbon To n-dodecanoyl chloride (43.6 parts) in an atoms (octanoyl and higher‘ halides) by dissolv hydrous ether (350 parts) is added triethylamine ing the acyl halide in an inert solvent and add ‘(20.6 :parts). These materials are thoroughly ing a chemically equivalent amount of the ter 40 mixed out of contact with air, then left at room _' tiary aliphatic amine with exclusion of moisture, temperature for 3 days. Filtration yields tri 1. e., under anhydrous conditions. The acyl hal ethylamine hydrochloride (28 parts or the theo ide may also be added to the amine in‘ an inert retical am'ount) melting at 251-4° C. When the solvent. The reaction mixture is agitated and solvent is evaporated from the filtrate in vacuo if necessary cooled to abstract the heat of reac 45 and the residue crystallized from ‘acetone, do tion. At 0°~25° C., the time required for com decanoyldecylethenone, a compound of the above plete reaction varies from 1-16 hours, depending .' probable formula and melting at 41-42’ C. is ob on the acyl halide and-amine used. Dehyd'ro tained in 90% yield. This compound was found halogenation is usually complete in an hour at on analysis to contain 78.78% carbon and 12.19% room temperature when trimethylamine is em 50 hydrogen. and to have a molecular weight of 2 ' 2,869,919 351. The calculated values are 79.10%, 12.09%, Exmrta IV and 364, respectively. The following table lists the proportions of 3-methylbutanolllisopfomllethenone reactants used and the yields of dodecanoyldecyl CHa-CH(CH3) CHzCOC(CH(CH3) 2) =C=O ethenone obtained from dodecanoyl chloride in 5 To 3-methylbutanoyl chloride (216 parts) in similar experiments. anhydrous ether (715 parts) is added gaseous an Pms Amine Solvent Reaction Per n‘dodecan- ' cent oyl chlonde Nature Parts Nature Parts Time Temp. yield Hours ‘’ C. 6 Ethyl ether. 160 25 78 6 Benzene"... 160 25 78 e Ethyl ether. 160 25 ‘7s 6. 9 Benzene“... 100 l 78 92 8 Xylene ____ -_ 110 l 135 100 Exmu: II hydrous trimethylamine with stirring until all 0ctadecanoylhewadecylethenone and its deriva evidence of reaction ceases. The resulting mix 20 ture is allowed to stand at room temperature for tives CI7H3SCOC(C16H33) =C=O 16 hours, the trimethylamine hydrochloride ?l To n-octadecanoyl chloride (15 parts) in an tered off, and the solvent evaporated from the hydrous benzene (180 parts) is added triethyl ?ltrate. The residue, amounting to 28 parts or a amine (6 parts) .- Dehydrohalogenation com 60% yield, is 3amethylbutanoylisopropylethenone mences almost immediately, and the reaction of the above probable formula. It boils at mixture is permitted to stand at room tempera 108-,110n C./35 mm., has an index of refraction, ture for 16 hours. After ?ltering out 6.9 parts ND25, of 1.4343, and a molecular weight of 163 of triethylamine hydrochloride (the theoretical ‘ (calculated value 168). This substituted ethenone ~ yield), the ?ltrate is concentrated on a steam may readily be converted into alpha-isovaleryl bath in vacuo, and the residue is taken up in pe isovaleranilide (M. P. 105-6° C.) by reaction with troleum ether (32 parts). Upon cooling, 12 parts aniline and into ethyl alpha-isovalerylisovalerate or a 97% yield of octadecanoylhexadecyleth (B. P. 135° C./32 mm.) by reaction with ethyl al enone, a compound of the above probable formula cohol. The former compound had a nitrogen and melting at 62-3° C., is obtained. It was content of 5.7%. and the latter a saponi?cation found to have a molecular weight of 494 and car number of 265, values which check closely with bon and hydrogen contents of 80.4% and 12.3%.. the theoretical. The identity of these derivatives The calculated values are 532, 81.1% and 12.7%, further characterizes the substituted ethenone. respectively. In the preparation of many chem EXAMPLE V ical derivatives, e. g., from amines and hy droxylated compounds, it is not necessary to iso 40 Propanoylmethylethenone late the substituted ethenone from’ the solvent. CH3CH2C0C(CH3) =C'=O Thus, to a, portion of the ?ltrate containing the Triethylamine (200 parts) is added slowly and octadecanoylhexadecylethenone is added a with agitation over a period of 2 to 3 hours to a chemically equivalent amount of aniline. The mixture of anhydrous ether. (980 parts) and compound alpha-octadecanoylstearanilide pre propanoyl chloride (179 parts) contained in a re cipitates from the solution and melts at 77-8“ C. action vessel ?tted with a re?ux condenser, a after recrystallization from alcohol. It has a ni stirrer, and a means for slowly adding the amine. trogen content of 2.6%, which checks the theo After the mixture has stood at room temperature retical within experimental error. for 20 hours, ?ltration by the “inverted method” In Example II above, octadecanoyl bromide described in Organic Syntheses, vol. XVI, p. 82, may be substituted for octadecanoyl chloride, and is employed, and the theoretical amount of tri the same compound obtained in yields of around ethylamine hydrochloride is separated. On 80%. Ether or benzene may be used as the sol evaporating the "solvent from the ?ltrate, there vent. _ I is obtained 75 parts or a 74% yield of alpha EXAMPLE III propanoylmethylethenone, a compound of the Octanwlhexillethenone above probable formula, 13. P. 57-8° C./12 mm. C1H15COC'(C'aH13) =C=O and ND25 1.4280. It was found to have a molecu lar weight of 114, and carbon and hydrogen con To n-octanoyl chloride (53 parts) in 355 parts tents of 63.88% and 7.61%. The calculated values of anhydrous ether is added triethylamine (34 are 112, 64.29%, and.'1.15%, respectively. parts). The reaction mixture is agitated out of Any solvent which dissolves and is inert toward contact with air and cooled in ice for 20 minutes acyl halides, tertiary amines, and ethenones is to offset the heat of reaction. The mixture is operable. Thus, a wide variety of solvents, in set aside for 2 days at room temperature, and cluding ethers, aromatic or aliphatic hydrocar the triethylamine hydrochloride then ?ltered off, bons, aromatic or aliphatic chlorinated hydrocar 96% of the theoretical amount being obtained. ' hons containing inactive halogen atoms, such as The solvent is evaporated from the ?ltrate. The trichlorethylene or carbon tetrachloride, are suit . residue (15 parts, or 75% yield) .is octanoyl-' able, Chlorinated hydrocarbons not suitable as hexylethenone, a compound of the above probable solvents include benzyl chloride and alpha- or formula.