Nano-CeO2 Catalyzed Efficient Synthesis of Benzoxazole and Benzimidazole by the Reaction Between 2-Amino phenol and 1, 2-Phenyldiamine with Trimethyl orthoformate

Benzoxazoles are the most important heterocyclic compounds that have wide range of pharmacological activities, synthetic and industrial applications [1]. Benzoxazoles have also attracted considerable research attention due to their unique properties and wide applications. Benzimidazoles are very useful intermediates for the development of molecules of pharmaceutical or biological interest [2]. In this work we wish to report efficient synthesis of benzoxazole from the reaction of 2-aminophenol and trimethylortho formate in the presence of nano cerium oxide (IV) as a catalyst in DMF under reflux condition for specified time at a certain temperature (Scheme 1). Benzimidazole also was synthesized from the reaction of 1,2-phenyldiamine with trimethylortho formate in the presence of nano cerium oxide (IV) as a catalyst (Scheme 2). Nano cerium oxide (IV) is not soluble in the solvent and can separate very simple from the reaction. Another benefit of this method can be referred to high yield and easy work-up.