Trichloroisocyanuric Acid–Mediated One-Pot Synthesis of Unsymmetrical 2,5-Disubstituted 1,3,4-Oxadiazoles at Ambient Temperature

Abstract

An efficient method for the one-pot synthesis of unsymmetrical 2,5-disubstituted 1,3,4-oxadiazoles has been developed using trichloroisocyanuric acid (TCCA) at ambient temperature. A wide variety of aromatic as well as heterocyclic aldehydes exhibit condensation with a variety of acylhydrazines followed by oxidative cyclization to yield corresponding unsymmetrical 2,5-disubstituted 1,3,4-oxadiazoles. The mild nature of the synthesis and short reaction time are notable advantages of the developed protocol.

Keywords:

• Acylhydrazines
• acylhydrazones
• oxidative cyclization
• 1,3,4-oxadiazoles
• trichloroisocyanuric acid

ACKNOWLEDGMENT

Authors (D.M.P., U.V.D.) thank University Grants Commission, New Delhi, for financial assistance [F.33–260/2007(SR)].

Notes

^a Yields refer to pure isolated products.

^a Yields refer to pure isolated products.

^b All products gave satisfactory spectroscopic (IR, ¹H NMR and ¹³C NMR) analysis.