one-pot synthesis of benzimidazole derivatives under microwave irradiation and solvent-free condition

a simple, fast, efficient and environmentally friendly method for synthesis of benzimidazole and its 2-alkyl, aryl and heteroaryl substituted derivatives was developed using zeolite hy. two component cyclolcondensation of 1,2-phenylenediamine (o-phenylenediamine) and commercially available carboxylic acids catalyzed by zeolite hy without any solvent, under microwave irradiation led to formation of 1h-benzimidazole and 2-substituted derivatives in high yields and purity. the similar reaction was not applicable to the preparation of benzimidazole and its 2-alkyl, aryl and heteroaryl substituted derivatives. all the synthesized compounds were characterized by 1h-nmr, ir, mass and chns analysis.