Synthesis of 1,2,4-oxadiazolidine derivatives from 1,3-cycloaddition reaction of nitrones onto Schiff bases

421- (3a-l) (31) (1a,b) (2a-f) . . A series of new heterocyclic compounds of 1,2,4-oxadiazolidines (3a-l) were synthesized by 1,3-dipolar cycloaddition reaction of different nitrones (1a,b) with different Schiff bases (2a-f) under reflux condition in good yields.The structures of all synthesized compounds were confirmed by physical and spectral data.