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. It boils at 135-'7° C./2 mm., has an in- v 70 beta-chloroethers. In those cases where the ‘sub dex of refraction (ND25) of 1.4489, a molecular stituted ethenones are isolated by distillation, it is ‘_ weight of 234, and carbon and hydrogen, con most convenient to choose a solvent boiling either tents of 76.29% and 11.24%. The calculated considerably below or above the substituted eth molecular weight and carbon and hydrogen con enone, thereby facilitating the separation of tents are 252, 76.2%, and 11.1%, respectively. 76 the product from the solvent. .Such a choice is

1 2,369,919 3 especially bene?cial in preparing and isolating the radicals attached to the amino nitrogen or the lower substituted ethenones when distillation nitrogens are aliphatic in character, or, more is used in the separation. Speci?c suitable sol-_ simply, saturated tertiary aliphatic amines free vents include ligroin, benzene, toluene, xylene, of active hydrogen. This particular terminology chlorobenzene, dichlorobenzene, diethyl ether, di is used to embrace, among others, tertiary amines ' butyl ether, chloroform, carbon tetrachloride, and (1) in whichthe three amino nitrogen valences trichloroethylene. ' are each satis?ed by a saturated open chain alkyl The amount of solvent may be varied within radical; (2) those in which one or more of the wide limits. Using 100-200 parts solvent per nitrogen valences are satis?ed by saturated mon tenth mol of each reactant has been found satis 10 ovalent cycloalkyl radicals, and (3) those in factory. The amount of solvent used should be which one of the valences is satis?ed by a satu su?icient to dissolve the substituted ethenone, rated open chain or cycloalkyl radical and two thus facilitating the separation of the insoluble valences are satis?ed by a single bivalent radi-' tertiary amine hydrochloride by ?ltration. It cal, as in the, piperidine and morpholine rings. is also feasible to use an excess of the tertiary 15 Where the tertiary amine is a polyamine the aliphatic amine as solvent in cases where the nitrogens must be separated by a chain of at substituted, ethenone can be readily separated least two carbon atoms. Saturated tertiary acy from the amine and its hydrochloride. The de clic amines free of active hydrogen are pre hydrohalogenation can be carried out in the ab ferred. Speci?c suitable amines include tri sence of a solvent when the presence of the amine 20 methylamine, triethylamine, tri-n-propylamine, hydrochloride in the product is not objectionable methyldiethylamine, ethylmethylpropylamine. in the use to which the latter is to be vput. benzyl-N,N-dimethylamine, l-ethylpiperidine, l A wide temperature range for the reaction is isopropylpiperidine, l-methyl-hexahydroazepine, also permissible. The process may be carried l-methylpyrrolidine, N,N,N',N'-tetramethyleth out successfully at temperatures rangingfrom‘ 25 ylenediamine, N-methylmorpholine, N-methyl- ' 0° C. to 140° C., and in many instances tem thiomorpholine, cyclohexyl-N,N-diethylamine, - peratures above and. below this range may be >ethyl-N,N-dicyclohexylamine, N,N,N',N'-tetra -used. The process is ordinarily carried out at methylhex'amethylenediamine, . 1,3-di(1-piperi atmospheric pressure (i. e., about 760 mm.), but dyDpIopane and l,4-bis(diethylamino)butane. operation at pressures above or below atmospheric 80 Tertiary amines which have been found not to is feasible. dehydrohalogenate acid halides of the above type As already indicated, the invention is generi- under conditions disclosed herein are pyridine, cally applicable to primary acid halides dimethylaniline, bis (dimethylamino) methane, R—CH2--CO—X and dipiperidinomethane. 35 For complete reaction, equivalent quantities wherein X is any halogen and R is a monovalent of amine and acyl halides are desirable. An organic radical which is chemically inert at tem excess of one of the reactants is not harmful but peratures up to 170° C. towards tertiary amines, may introduce some difficulty inisolating the

acyl halides and ethenones. Alternatively, the product. ' ' ' acid halide may be designated as a primary 40 A most important condition of the process is monoacyl halide of at least three carbon atoms that .both the reaction and the isolation of the and free of reactive groups other than the one product take place under anhydrous conditions. acid halide group. ‘The symbol)! in the formula If these conditions are not ful?lled, the reac just given is preferably chlorine, but may be tion may take quite a different course. ?uorine, bromine, or iodine. R is preferably a 45 On the basis of the reactions they undergo, the , hydrocarbon radical such as aryl, aralkyl, cyclo substituted ethenones have been assigned the alkyl, and open chain aliphatic hydrocarbon (especially alkyl), but may contain inert radicals formula ' . such as carbalkoxy, alkoxy, aryloxy, aralkoxy, ' R-CH2—CO--C’(R)=C=0 halogen attached to aromatic carbon, ketonic car 60 where R is the residue R of the acid halide bonyl, tertiary amide (i. e. having no amido hy RCI-Iz-COX and, as previously indicated, is an drogen), or aliphatic heterocyclic radicals. By organic radical which is unaffected at'tempera the latter is meant radicals not having benzene. tures up to 170? C, by tertiary amines, acid halides, type unsaturation,., which is commonly repre and ethenones. Evidence for the beta-ketonic sented by three alternating double bonds in a 55 structure lies in the fact that the, products on ring structure. The heterocyclic radical may thus hydration are converted to acids which on heat be saturated or unsaturated. Types of radicals ing lose carbon dioxide with formation of a which should not be present are aromatic hetero ketone, a reaction which is characteristic of beta cyclic radicals, amide groups containing amido ketoacids. hydrogen, and acyloxy groups. Speci?c acid 60 Two mechanisms which may account for the halides that are suitable include the following: production of substituted ethenones by the re n-octadecanoyl, 9,10-octadecenoy1 (oleyl), lino action‘ of a primary acid chloride and a tertiary leyl, n-hexadecanoyl, n-tetradecanoyl, n-dodec amine are given in the following series of equa anoyl, n-decanoyl, n-nonanoyl, n-octanoyl, n hexanoyl, n-heptanoyl, 3-,methylbutanoyl, n-bu .65 , tanoyl, n-propanoyl, delta-carbomethoxypenta noyl, 4-(N-dimethylamino) -butanoyl, 4-phenox ybutanoyl, 5- ( 2,3,5-trichlorophenoxy) pentanoyl, S-keto-octanoyl, and 10-furyldecanoyl chlorides, and also the corresponding bromides, iodides and 70

?uorides. , . The invention is generic to the use of tertiary saturated mono- or poly-amines free from active hydrogen (hydrogen bonded to an inorganic ele ment, e. g., 0, 8, Se, Te, N, P,-As), in which all The exact course of this reaction cannot be de 4 . 2,869,919 ?ned on the basis of known facts. In view of utility, are generally obtained in better yields, this, the products are best de?ned as intermolec are more readily crystallized, and are on the ular dehydrohalogenation products of primary whole more stable in being less sensitive to acyl halides of the probable formula given above, moisture and capable of preservation for long which products melt below 100° C. ' periods. In ‘the'latter respect all the products The ‘substituted ethenones of the present in 01' the present invention are markedly di?’erent vention may be used in the preparation of sym from the known aldoethenone, acetylethenone, m‘etrical ketones, substituted beta-keto amides, in that the latter polymerizes and darkens rap anilides, and esters. Many of these derivatives idly. are useful as dye intermediates. The substituted According to the prior art dehydroacetic acid ethenones derived from acyl halides of at least is the only product obtained by the dehydrohalo seven carbon atoms are particularly useful in genation of acetyl chloride with triethylamine in that they have the ability to impart a desirable an inert solvent or pyridine in a sealed tube. It waterproo?ng effect to organic ?brous materials. was’ therefore unexpected and surprising that This is more fully described in copending appli 15 compounds analogous to dehydroacetic acid were cation Serial Number 234,842 filed October 13,. not formed in the dehydrohalogenation of the 1938, by W. E. Hanford. The higher the carbon higher primary acyl halides. The isolation of content or the acid halide, the better the water substituted ethenones of the type ‘ proo?ng. Thus the products from octanoyl, do decanoyl, and octadecanoyl chlorides gave notice 20 able, substantial, and excellent water-proo?ng was also unexpected since the literature teaches effects, respectively. The dehydrohalogenation that pyranones are the reaction products when products from acyl halides having up to about 6 ‘primary acid chlorides '(except acetyl chloride) carbon atoms, however, may also be applied to are dehydrohalogenated. These pyranones are organic ?brous materials, and, while in general 25 not water-sensitive. ' Theproducts of the present no exceptional water-proofing is observed, there invention must be prepared, isolated and handled is obtained favorable alteration of dyeing char under anhydrous conditions. -~ ~ - ' acteristics. The products from acyl halides of The above description and examples are-in comparatively higher carbon content, i. e., those tended to be illustrative only. Any modi?cation having about twelve or more carbons, impart of or variation therefrom which conforms to the both'softening and water-repellent effects to spirit of the invention is intended to be included fabrics. A further use for the products of the within the scope of the claims. present invention is in the treatment of cellulose I claim: " acetate, to which the products from; propanoyi 1. Octadecanoylhexadecylethenone. and octanoyl chlorides, in particular, impart a 2. A process which comprises reacting octa a greater water resistance. decanoyl chloride with triethylamine in an an This invention provides a simple, economical hydrous solvent, and thereafter separating from and convenient method of making new and , the reaction products the so-formed octadeca ‘hitherto unavailable products. Those derived noylhexadecylethenone, the entire process being from acid halides of eight or more carbons are 40 conducted under anhydrous conditions. especially important in that they have a wider JOHN CARL SAUER.