PREPARATION OF GAMMA-KETOCARBOXYLIC ACID

PURPOSE:To prepare the titled compound useful as an intermediate of pharmaceuticals, by reacting an aniline derivative with an acid anhydride in the presence of aluminum chloride in a mixed solvent composed of a specific amide and tetrachloroethane. CONSTITUTION:The gamma-ketocarboxylic acid of formula III can be prepared by reacting an aniline derivative of formula I (R is 1-4C alkyl) with an acid anhydride of formula II (R and R are H, methyl or ethyl; dotted line is single or double C-C bond) in the presence of aluminum chloride in a mixture of (A) an amine selected from dimethylformamide, dimethylacetamide and N-methylpyrrolidone and (B) tetrachloroethane. The molar ratio of the aniline derivative to the acid anhydride is preferably 2.0-0.5, and the amount of aluminum chloride is 5-15mol per 1mol of the lesser component in the aniline derivative and the acid anhydride. The reaction temperature is preferably 20-60 deg.C.