CARBOXYLATION OF PHENOLS AND HYDROXYAROMATIC CARBOXYLIC ACIDS PRODUCED THEREBY

1,219,205. Carboxylation of phenols and hydroxyaromatic carboxylic acids produced thereby. FERRO CORP. 5 April, 1968 [7 April, 1967; 14 March, 1968], No. 16453/68. Heading C2C. Hydroxyaromatic carboxylic acids are prepared by carboxylating a phenol in the presence of a solvent at least 15% by weight of which is an aliphatic N,N-dimethylamide having 3 to 10 carbon atoms. The process is preferably carried out in the presence of an uncarbonated metalalk oxide. The invention also comprises carboxylic acids of formula wherein n is 0 or 1; R1 and R11 which may be the same or different, are hydrogen, halogen, amino, mono-alkyl or dialkyl amino, hydroxyl, an alkoxy radical having 1 to 15 carbon atoms, an alkyl radical having 1 to 15 carbon atoms, or an aromatic radical having 5 to 20 carbon atoms; and X is a bivalent alkylidene radical having at least 3 carbon atoms, and of the formula wherein R1 and R11 which may be the same or different are halogen, amino, mono-alkyl or dialkyl amino, hydroxyl, an alkoxy radical having 1 to 15 carbon atoms, an alkyl radical having 1 to 15 carbon atoms or an aromatic radical having 5 to 20 carbon atoms and wherein one of R1 and R11 may be hydrogen. Specified compounds are 2-(4-hydroxy-3-carboxyphenyl) - 2 - (4 - hydroxyphenyl) propane; 2,2- bis (4 - hydroxy - 3 - carboxyphenyl) propane and 7-carboxy-8-hydroxyquinaldine.