PURPOSE: To produce an arom. carboxylic acid in a high yield at a high selectivity by an easier and more economical process than conventional processes by directly oxidizing a methyl-substd. arom. compd.
CONSTITUTION: A compd. of the formula: Ar(CH3)n (wherein Ar is an iso- or heteroarom. group optionally having inert substituents) is oxidized with a nitrogen/oxygen compd. having an oxidizing action (e.g. nitric acid, dinitrogen pentaoxide, or nitrogen dioxide) in a liq. phase in the presence of sulfuric acid and a vanadium compd. (e.g. vanadium pentaoxide) in an amt. thereof of 20-100 mol.% (based on the raw material compd.) at 120-180°C, pref. 130-170°C, to give an arom. carboxylic acid of the formula: Ar(COOH)n. This process is effective in producing a heteroarom. carboxylic acid, esp. quinolinecarboxylic acid.
ANDOREASU GURUDONAA