Synthesis of 2-methylbenzoxazoles directly from N-phenylacetamides catalyzed by palladium acetate

Abstract

A method to synthesize 2-methylbenzoxazoles directly from N-phenylacetamides catalyzed by Pd(OAc)₂ in the presence of K₂S₂O₈ and TfOH has been developed. The desired products were obtained in moderate to excellent yields. This approach provides a facile procedure to prepare benzoxazoles with available substrates. It is found that TfOH is the key factor for this cyclization reaction. A plausible mechanism of the reaction is proposed according to the control reactions and the literature.