Yttrium (III) chloride: A mild and efficient catalyst for the synthesis of benzimidazoles.

A simple and efficient synthesis of benzimidazole derivatives from orthophenylene diamine and aldehydes by using a Lewis acid catalyst yttrium (III) chloride has been described. Compared with classical benzimidazole synthesis, this method has advantage of excellent yields and short reaction times. All the reactions were carried out using the catalyst in 10 mol %, in acetonitrile at room temperature.