An Efficient Synthesis of 2-Substituted Benzoxazoles via RuCl3·3H2O Catalyzed Tandem Reactions in Ionic Liquid

An efficient synthesis of 2-substituted benzoxazoles through RuCl3·3H2O catalyzed, air oxidized tandem reactions of 2-aminophenols and aldehydes in [bmim]BF4 was developed. This synthetic strategy has such advantages as mild reaction conditions, cost-free oxidant, readily available starting materials, and recyclable catalyst and solvent. As an application, it was successfully used in the synthesis of the unreported 5-(benzoxazol-2-yl)-2′-deoxyuridines with potential biological activities.