Patent GB-507204-A (GB)
Title: Improvements in the manufacture and production of high molecular weight aldehydes, ketones and alcohols
IPC: C07C45/84
Filed: 1937-12-07
Abstract: 507,204. Aldehydes ; ketones ; alcohols. JOHNSON G. W. (I. G. Farbenindustrie Akt.-Ges.) Dec. 7, 1937, No. 33881. Samples furnished. [Class 2 (iii)] Aldehydes or ketones of high-molecular weight are obtained by the condensing action of a secondary amine or a salt thereof on (a) an aldehyde containing a, reactive methylene or methyl group, or a mixture of such aldehydes with one another or with other aldehydes, or (b) a mixture containing an aldehyde of any kind and a ketone containing a reactive methylene or methyl group, the reaction being effected under such conditions that the water formed is continuously removed. A "reactive" methylene or methyl group is defined as a methylene or methyl group adjacent to a carbonyl group or an olefinic linkage. The aldehydes containing a reactive methylene or methyl group may be of the type RCH2(CR<1> : CH)nCHO, where R is hydrogen or an aliphatic, cycloaliphatic, aliphatic-aromatic, or aromatic radicle, n is zero or an integer, and R<1> is hydrogen or an aliphatic or carbocyclic radicle; specified aldehydes of this type are acetaldehyde, n-butyraldehyde, crotonaldehyde, 3-methylbutene - 2 - al @1, stearic aldehyde, oleic aldehyde, citral, #-ionylidene acetaldehyde and phenylacetaldehyde. Specified ketones containing a reactive methylene or methyl group are acetone, methylethyl ketone and ionone. Specified aldehydes which do not contain a reactive methylene or methyl group, and which may be condensed in association with aldehydes or ketones containing such a group, are glyoxal benzaldehyde, cinnamic - aldehyde, o- and p-dihydrotoluylaldehydes, furfurol and quinolinealdehydes. The aldehydes and ketones may contain substituents, such as halogen atoms or hydroxy groups; thus, acetaldol and #-chlorbutyraldehyde may be treated. Suitable secondary amines for effecting the condensation are dimethylamine, diethylamine, dibutylamine, dicyclohexylamine, piperidine, piperazine, hydroquinoline, morpholine and hydrothiazines; salts of these amines with formic, acetic, crotonic, palmitic, oxalic, succinic, lactic, chloracetic, phosphoric or boric acid or with malonic acid monomethyl ester may also be used. The removal of water during the reaction may be effected (a) by simple distillation, optionally under reduced pressure and/or with passage of an inert gas through the mixture, or (b) by addition of a water-binding agent, such as sodium acetate, or (c) by azeotropic distillation, for which purpose the auxiliary liquid used may be a hydrocarbon such as heptylene, isooctane, cyclohexane, benzine, benzene, toluene or xylene, or a chlorinated hydrocarbon such as methylene chloride, trichlorethylene or carbon tetrachloride, or an alcohol such as methanol, ethanol or butanol, or an ether such as diethyl or dipropyl ether or dioxane, or the carbonyl compound undergoing condensation. The condensation may be effected at 30-80‹ C. and any convenient pressure, and the condensing agent and/or the material to be condensed may be added to the mixture in a single batch or in stages. The products may be converted into unsaturated alcohols by reduction, or they may be hydrogenated to yield saturated aldehydes, ketones and alcohols. In the examples, (1) crotonaldehyde is condensed in the presence of morpholine acetate, and the water formed is removed by azeotropic distillation with the aid of benzene ; a mixture of unsaturated aldehydes containing eight carbon atoms or more is obtained, and is hydrogenated in n-octyl alcohol in the presence of a nickel catalyst; the products include dodecyl and cetyl alcohols; (2) a mixture of cyclohexanone and benzaldehyde is condensed in the presence of piperidine acetate, and the water formed is removed by azeotropic distillation with the aid of toluene; 2 : 6-dibenzylidenecyclohexanone is obtained; (3) crotonaldehyde is condensed in the presence of morpholine acetate and chloracetate as in example 1, and the product is hydrogenated as in example 1. Samples have been furnished under Sect. 2 (5), of products prepared as follows:-(1) citronellal is condensed in the presence of morpholine acetate to yield a mixture of aldehydes from which citronellidene citronellal (formula given) is obtained by fractional distillation; (2) citral is condensed in the presence of morpholine acetate, and the product is hydrogenated in the presence of a nickel catalyst to yield a mixture of alcohols containing 20, 30, 40 or more carbon atoms; (3) phenylacetaldehyde is condensed and the product is hydrogenated, as described for sample 2; a mixture of alcohols containing 16, 24 or more carbon atoms is obtained ; (4) an impure aldol is condensed and the product is hydrogenated, as described for sample 2 ; a mixture of alcohols containing 12 or more carbon atoms is obtained ; (5) acetaldehyde is condensed in the presence of morpholine acetate and chloracetate, and the product is hydrogenated, as described for sample 2 ; a mixture of alcohols containing 12, 14, 16, 18 -or more carbon atoms is obtained ; in each case, the water formed during the condensation is removed by azeotropic distillation.