GB699556A - Process for the production of aliphatic carboxylic acids and esters of the same - Google Patents

Abstract

Aliphatic carboxylic acids and their esters are produced by the reaction of saturated alcohols with carbon monoxide at elevated temperature and superatmospheric pressure in the presence of catalysts consisting of metal carbonyls and a halogen or a halogen compound while having present during the whole course of the reaction an appreciable amount of an organic liquid solvent inert under reaction conditions and having a critical temperature above the reaction temperature. The preferred temperature range for the process is 250-320 DEG C. and the preferred pressure range is 200-300 atmospheres. Suitable inert solvents are the aliphatic carboxylic acids which are formed in the reaction, carboxylic acid esters, higher paraffinic hydrocarbons, cyclohexane homologues and benzene and its next higher homologues. Non-aromatic saturated ketones or higher boiling tertiary amines, such as pyridine or dimethylaniline may also be used. The catalyst should be either a metal carbonyl or capable of forming a metal carbonyl under the reaction conditions. Halogen either in the form of a halogen compound, e.g. a halogenated hydrocarbon or free halogen, is also essential. Iodine is the preferred halogen. Bismuth may be used as an additional activator. In the examples methyl alcohol is reacted with carbon monoxide in the presence of (a) nickel acetate and iodine; (b) nickel metal and iodine; (c) nickel carbonyl and iodine, and (3) nickel carbonyl, iodine and bismuth in the presence of various solvents to give acetic acid and methyl acetate.