Patent GB-506850-A (GB)
Title: Improvements in the manufacture and production of high molecular weight aldehydes, keytones and alcohols
IPC: C07C29/141
Filed: 1938-02-02
Abstract: 506,850. Aldehydes, ketones, and alcohols. I. G. FARBENINDUSTRIE AKT.- GES. Feb. 2, 1938, No. 3275. Convention date, Feb. 6, 1937. [Class 2 (iii)] Aldehydes and ketones of high molecular weight are made by condensation of acetaldehyde or aldehydes obtainable therefrom containing hydroxy groups or double bonds, or mixtures of such aldehydes with other aldehydes or. ketones containing at least one - reactive methyl or methylene group, the condensation being effected by means of small amounts of salts of amines in the presence of an excess of weak inorganic acids or an excess of at least 8 molecular proportions of monobasic organic acid (calculated on the amount of amine) and if desired, hydrogenating the products to obtain alcohols. As initial materials there may be used acetaldehyde, aldol and crotonaldehyde, which may be used in admixture with other aldehydes or ketones such as propionaldehyde, butyraldehyde, allyl aldehyde, palmitic aldehyde, oleyl aldehyde, acetone, methyl ethyl ketone, acetophenone, hexahydroacetophenone or substitution products thereof such as aldehydes or ketones containing halogen atoms, e.g: halogen butyraldehyde. Suitable aminesalts are the salts of ethylamine, ethanolamine, dimethylamine, diethylamine, dibutylamine, diamylamine, dicyclohexylamine, piperidine, pyrrole, pyrrolidine, decahydroquinoline, hydrogenated naphthoquinolines, #-#<1>-dichlordiethylamine, di- and tri-ethanolamine, and diethylbutanolamine. Suitable acids are formic, acetic, palmitic, lactic, crotonic, benzoic, hippuric, phosphoric, boric, and carbonic acids. The excess acids may be in the form of their anhydrides. 'Solvents or diluents such as dioxane, cyclohexane and ethyl alcohol may be employed. The condensation may be effected under reduced or increased pressure, which in the case of carbon dioxide may be 10-150 atmospheres. The products are unsaturated aldehydes or ketones and may be separated by fractional vacuum distillation. They may be converted into the corresponding unsaturated alcohols by reduction with sodium and alcohol or by' aluminium isopropylate,. or into the corresponding saturated aldehydes, ketones or alcohols by catalytic hydrogenation, if desired after separation of the amine salt and excess acid. Alternatively the hydrogenation may be effected so as to obtain partially unsaturated aldehydes, ketones or alcohols. In examples : (1) crotonaldehyde is heated in the water bath with piperidine and glacial acetic acid and the product after cooling is heated under reduced pressure to remove crotonaldehyde and some acetic acid, and is then distilled fractionally under high vacuum yielding three oily fractions consisting of unsaturated aldehydes which may be reduced to the corresponding unsaturated alcohols by aluminium isopropylate or to saturated aldehydes or alcohols by catalytic hydrogenation; (2) crotonaldehyde is heated with a solution of decahydroquinoline in ethyl alcohol and carbon dioxide is admitted at 20 atmospheres pressure; the mixture is cooled, nickel is added and hydrogenation is effected at 150 atmospheres the temperature not being allowed to exceed 60‹ C., yielding a mixture of saturated aldehydes; or the hydrogenation may be effected at 130‹ C. yielding an alcohol mixture boiling above 100‹ C. at 60 mm. pressure; (3) crude aldol is heated with piperidine and carbon dioxide is admitted at 25 atmospheres ; after cooling, nickel is added and hydrogenation is effected at 150 atmospheres yielding an alcohol mixture as in the preceding example. The Specification as open to inspection under Sect. 91 includes the use as starting materials of' any lower molecular weight saturated or unsaturated aldehydes or mixtures of aldehydes and, ketones and substitution products of aldehydes and ketones such as those containing hydroxy groups or halogens the process being effected in the presence of excess acid, mentions salts of morpholines as suitable amine salts and as suitable acids oxalic, malonic, succinic, fumaric, and mouochloracetic acids. This subject-matter does not appear in the Specification as accepted.