Method of producing keto acids

摘要

In a method of producing a keto acid having the general formula <IMAGE> wherein R1 and R2 independently represent an alkyl of 1-6 carbons or a cycloalkyl of 4-8 carbons, by reacting an m-aminophenol having the general formula <IMAGE> wherein R1 and R2 are the same as above, with phthalic anhydride, in an organic solvent, the improvement comprising effecting the reaction in an amount of the organic solvent which is insufficient to dissolve the keto acid produced in the reaction, so that at least a portion of the resultant keto acid crystallizes out of the solvent and allowing the reaction to proceed in a heterogeneous system.