Reaction of 4-substituted aminomethylene-2-phenyl-2-oxazolin-5-ones with primary amines

Abstract

The regioselective reactions of 4-(N,N-dimethyIaminbmethylene)-2-phenyl-2-oxa2olin-5-one 2b and 4-anilinomethylene-2-phenyl-2-oxazolin-5-one 2c with primary alkyl amines in acetonitrile afford the corresponding 4-alkylaminomethylene-2-oxazolin-5-ones 4 in excellent yields. Oxazolones 2b and 2c are resistant to aminolysis with primary aryl amines. However, compound 2c gives 3-anilino-2-benzoylaminoacrylanilide 9 with aniline in acetonitrile containing catalytic amount of acetic acid, via 1, 5-bond cleavage. The regioselectivity is explained by the hard-soft acid-base (HSAB) principle.