Process for producing quinoline-3-carboxylic acid compound

A process for producing quinoline-3-carboxylic acid represented by formula (3)

• 5
• wherein R1, R2, R3, R4 and R5 have the same meanings as defined below, characterized by reacting 2-aminophenyl ketone represented by formula (1)
• 6
• wherein R1 is an aryl group, a C1-12 alkyl group which may be branched, a C2-12 alkenyl group which may be branched, a C2-12 alkynyl group which may be branched or a C3-6 cycloalkyl group, and the aryl, alkyl, alkenyl, alkynyl and cycloalkyl groups may be substituted;
• and
• R2 and R3 are each a hydrogen atom, a halogen atom, a C1-12 alkyl group which may be branched, a C3-6 cycloalkyl group, a C1-12 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)
• R4COCH2CO2R5 (2)
• wherein R4 is a C1-12 alkyl group which may be branched, a C3-6 cycloalkyl group, or an aryl group, and the alkyl, cycloalkyl and aryl groups may be substituted, and R5 is a C1-6 alkyl group which may be branched,
• in the presence of an acid catalyst in an alcohol solvent while distilling off the alcohol.