Synthesis of Benzoxazoles from 2-Aminophenols and β-Diketones Using a Combined Catalyst of Brønsted Acid and Copper Iodide

Cyclization reactions of 2-aminophenols with β-diketones catalyzed by a combination of Brønsted acid and CuI are presented. Various 2-substituted benzoxazoles were obtained through these reactions. Different substituents such as methyl, chloro, bromo, nitro, and methoxy on 2-aminophenol are tolerated under the optimized reaction conditions.