FACILE SYNTHESIS OF ISONIAZID DERIVATIVES – 1-[2-(3-ARYL(HETARYL)-1-PHENYL-1H-PYRAZOL-4-YL)-5-(PYRIDIN-4-YL)-1,3,4-OXADIAZOL-3(2H)-YL]ETHANONES

Abstract

A facile and efficient ultrasound-aided approach has afforded cyclization of isoniazid hydrazones into 2,5-bishetaryloxadiazolines at ambient temperature. Acetic anhydride helped in intramolecular oxidative cyclization along with N-acylation of oxadiazoline. The synthesized 1-[2-(1-phenyl-1H-pyrazol-4-yl)-5-(pyridin-4-yl)-1,3,4-oxadiazol-3(2H)-yl]ethanones were isolated in good yields, spectral data supported the proposed structures.