SeO2 Mediated Synthesis of Selected Heterocycles by Oxidative C−C Bond Cleavage of AcetophenoneDerivatives

Abstract

An interestingcyclization reactions of aryl ketones with 2-amino aniline derivatives under SeO2 (oxidant) are described for the synthesis of benzoxazole, benzothiazole, benzimidazole and quinazolinone through the C−C cleavage of acetophenone. The reaction likely involves sequential C−N, C−O and C−S bond formation followed by C(CO)−C(alkyl) bond cleavage. Various substituted fused heterocycles are obtained in good to excellent (gram scale) yields in a single step from readily available acetophenones.