Reinvestigation of the reaction between aromatic aldehydes, 3-phenyl-5-isoxazolone and sarcosine: stabilized azomethine ylides as a synthetic equivalent of the methylaminomethyl anion

Abstract The reaction of aromatic aldehydes, 3-phenyl-5-isoxazolone and sarcosine proceeds smoothly at reflux in methanol to give (Z)-4-arylidene-3-phenylisoxazol-5(4H)-ones, whereas the addition of isatin to the reaction mixture changes the result, providing oximes of 4-aryl-3-benzoyl-1-methylpyrrolidin-2-ones in 38–72% yield.