TRANSFORMATION OF N-ACYLAMINOACETANILIDES AND N-BENZOYLGLYCINE HYDRAZIDES INTO N-DIMETHYLAMINOMETHYLENE)-2-ARYL-2-OXAZOLIN-5-ONES USING VILSMEIER-HAACK REAGENT AND THEIR REACTIONS WITH NUCLEOPHILES

A convenient one-pot synthesis of N-dimethylaminomethylene)-2-aryl-2-o xazolin-5-ones (5a-e) has been reported from the reaction of N-acylami noacetanilides (3a-1) and N-benzoylglycine hydrazides (4a,b) with Vils meier-Haack reagent. Compound 5a undergoes facile hydrolysis and base catalyzed alcoholysis but it is resistant to aminolysis with primary ( aliphatic/aromatic) amines. However, 5a on reaction with hydrazine hyd rate, undergoes facile hydrazinolysis to give 4-benzamido-3-pyrazolin- 5-one (8a) which is also obtained from 5a in a step-wise fashion. The plausible mechanism has been discussed.