GB790908A - Improvements in or relating to preparation of diaryl ketone polycarboxylic acids - Google Patents

Abstract

Diaryl ketone polycarboxylic acids are prepared by contacting a gas containing molecular oxygen with a substituted diaryl compound having the formula R-X-R1, wherein X is a <FORM:0790908/IV (b)/1> radical and R and R1 are aryl radicals, preferably phenyl or naphthyl, carrying respectively as nuclear substituents at least one alkyl radical containing 1 to 3 carbon atoms and at least one radical selected from alkyl radicals containing 1 to 3 carbon atoms and carboxyl radicals, in the presence of an oxidation catalyst at a temperature of 60 DEG to 200 DEG C. Other substituents inert to the oxidation such as chlorine atoms and alkoxy groups may be present. Specified oxidation catalysts are cobalt acetate, propionate, oleate and naphthenate. The catalyst is preferably dissolved in a solvent such as acetic, propionic or butyric acid or a mixture thereof with methyl ethyl ketone. In examples: (1) a mixture of ditolyl ketone isomers was oxidized with oxygen in the presence of cobaltous acetate, glacial acetic acid and methyl ethyl ketone and 2 : 41 - and 4 : 41 - benzophenone - dicarboxylic acids separated from the product; (2) a mixture of ditolyl methane isomers was oxidized with oxygen in the presence of a mixture of cobaltous acetate, glacial acetic acid and methyl ethyl ketone which had been pretreated with oxygen and 4 : 41- and 2 : 41-benzophenone-dicarboxylic were separated from the product; (3) as in (1) but o-(p-toluyl) benzoic acid oxidized to 2 : 41-benzophenone-dicarboxylic acid. Further specified oxidations are 4 : 41-dimethyl- or diethyl- or diisopropyl-benzophenone to 4 : 41-benzophenone-dicarboxylic acid, 3 : 31-dichloro-4 : 41-dimethyl-diphenylmethane to 3 : 31-dichlorobenzophenone - 4 : 41 - dicarboxylic acid, di-p-xylyl-methane to 2 : 5 : 21 : 51-benzophenone-tetracarboxylic acid and 1 : 11-dimethyl-2 : 21-dinaphthyl-methane to di-beta-naphthyl-ketone-1 : 11-dicarboxylic acid.