Patent ID: 6852862

Claim:
A process for producing quinoline-3-carboxylic acid represented by formula (3) wherein R 1 , R 2 , R 3 , R 4 and R 5 have the same meanings as defined below, characterized by reacting 2-aminophenyl ketone represented by formula (1) wherein R 1 is an aryl group, a C 1-12 alkyl group which may be branched, a C 2-12 alkenyl group which may be branched, a C 2-12 alkynyl group which may be branched or a C 3-6 cycloalkyl group, and the aryl, alkyl, alkenyl, alkynyl and cycloalkyl groups may be substituted; and R 2 and R 3 are each a hydrogen atom, a halogen atom, a C 1-12 alkyl group which may be branched, a C 3-6 cycloalkyl group, a C 1-12 alkyloxy group which may be branched, or an aryl group, and the alkyl, cycloalkyl, alkyloxy and aryl groups may be substituted, with a keto ester represented by formula (2) R 4 COCH 2 CO 2 R 5 (2) wherein R 4 is a C 1-12 alkyl group which may be branched, a C 3-6 cycloalkyl group, or an aryl group, and the alkyl, cycloalkyl and aryl groups may be substituted, and R 5 is a C 1-6 alkyl group which may be branched, in the presence of an acid catalyst in an alcohol solvent and distilling off the alcohol during the reaction of the 2-aminophenyl ketone with the keto ester.