Simple, mild, and highly efficient synthesis of 2-substituted benzimidazoles and bis-benzimidazoles

[摘要] A new convenient method for preparation of 2-substituted benzimidazoles and bis-benzimidazoles is presented. In this method, o-phenylenediamines were condensed with bisulfite adducts of various aldehydes and di-aldehydes under neat conditions by microwave heating. The results were also compared with results of synthesis by conventional heating under reflux. Structures of the products were confirmed by infrared, 1H- and 13C-NMR spectroscopy. Short reaction times, good yields, easy purification of products, and mild reaction conditions are the main advantages of this method.

[学科分类] 化学（综合）

[关键词] benzimidazole;microwave heating;synthesis.