Liquid-Phase combinatorial synthesis of aminobenzimidazoles

Liquid-phase synthesis of 2-arylaminobenzimidazoles using soluble polymer support strategy is first described. The key step to benzimidazole skeleton is achieved in the presence of diisopropylcarbodimide (DICDI) and isothiocyanates. A mechanism study for one-pot cyclodesulfurization is also investigated on the support. A wide range of benzimidazole derivatives is synthesized in excellent yield and purity just by simple wash and precipitation.