Synthesis of 2-Aryl Benzoxazoles from Aldoximes

Abstract

Wide spectrum of biological activities of benzoxazole heterocycles aroused great interest for the development of newer methods for their synthesis. We herein report a copper catalyzed method for the synthesis of 2-aryl benzoxazoles from the reaction of aldoxime and 2-iodobromobenzene using N,N'-dimethyl ethylenediamine (DMEDA) as the ligand. The reaction proceeds with the copper-catalyzed dehydration of aldoxime leading to the nitilium ion which might be undergoing hydrolysis and subsequent C-O bond formation in one-pot to afford 2-aryl benzoxazoles. The pure products were isolated and characterized by 1 H NMR, and 13 C NMR data.