An N-methylketimine has been found to be an effective reagent in the Erlenmeyer azlactone synthesis. 2-Phenyl-4-diphenylmethylene-5 (4H)-oxazolone (1) has been synthesized by the reaction of 2-phenyl-5 (4H)-oxazolone (A) with N-methyl-diphenylmethanimine (B), contrary