REACTION OF 4-SUBSTITUTED AMINOMETHYLENE-2-PHENYL-2-OXAZOLIN-5-ONES WITH PRIMARY AMINES

The regioselective reactions of -dimethylaminomethylene)-2-phenyl-2-ox azolin-5-one 2b and 4-anilinomethylene-2-phenyl-2-oxazolin-5-one 2c wi th primary alkyl amines in acetonitrile afford the corresponding 4-alk ylaminomethylene-2-oxazolin-5-ones 4 in excellent yields.' Oxazolones 2b and 2c are resistant to aminolysis with primary aryl amines. Howeve r, compound 2c gives 3-anilino-2-benzoylaminoacrylanilide 9 with anili ne in acetonitrile containing catalytic amount of acetic acid, via 1, 5-bond cleavage. The regioselectivity is explained by the hard-soft ac id-base (HSAB) principle.