Efficient Synthesis of 2-Substituted Benzoxazoles via Beckmann Rearrangement of 2-Hydroxyaryl Ketoximes Using Diethyl Chlorophosphate

Abstract

An efficient method for synthesis of 2-substituted benz­oxazoles has been developed using diethyl chlorophosphate. 2-Hydroxyaryl ketoximes are efficiently converted to benzoxazoles by heating in the presence of diethyl chlorophosphate via Beckmann rearrangement of ketoxime in excellent yields. This method avoids the use of strong acids, harsh conditions, and long reaction times.

benzoxazoles - Beckmann rearrangement - cyclization - 2-hydroxyaryl ketoximes - diethyl chlorophosphate

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