REACTION OF ARYL- AND HETEROARYL BENZOYL- AND ACETYLHYDRAZONES WITH PHENYLISOCYANATE SYNTHESIS OF SUBSTITUTED-2,3-DIHYDRO-1,3,4- OXADIAZOLES

Abstract

Aryl benzoylhydrazones (1a-c) react readily with phenylisocyanate (2) at room temperature to give the corresponding substituted 2,3-dihydro-1,3,4-oxadiazoles (3a-c). On the other hand, the reaction of benzoylhydrazones of furan, thiophene and pyridine carbaldehydes gave 2,5-dioxo-1,5-diphenyl-1,3,4-triazapentane (4), and that of theiophene acetylhydrazone gave 2,5-dioxo-1-phenyl-1,3,4- triazahexane (5). Structure elucidation of these compounds was based on spectral data including IR, Ms and NMR.