Reaction of Oximes of α-Diketones with Diphosphorous Tetraiodide for Preparation of Oxadiazoles and Nitriles

Abstract

The utility of diphosphorous tetraiodide as a new, mild, condensing agent for synthesis of oxadiazole is described. These data indicate the simple dehydration of oximes to 1,2,5-oxadiazole as well as the rearrangements of oximes to normal Beckmann product 1,2,4-oxadiazole. However, mono-oxime of benzil undergoes abnormal Beckman rearrangement to benzaldehyde as major product. The described method is simple and important for the synthesis of the oxadiazoles as well as for nitriles.

GRAPHICAL ABSTRACT

Keywords:

• Benzildioxime
• benzonitrile
• diphosphorus tetraiodide
• oxadiazole

ACKNOWLEDGMENT

V. N. T. is grateful to the Department of Science and Technology, India, for financial support under SERC Fast Track Young Scientists Scheme.

Notes

^a Reaction conditions: Substrate (1 mol) and P₂I₄ (0.5 mol) in dichloromethane at room temperature.

^b Isolated yields after column chromatography and structures were confirmed by comparison of IR and ¹H NMR with authentic materials.