Soluble polymer-supported synthesis of 2-(arylamino)benzimidazoles

A novel liquid-phase method for the construction of biologically important benzimidazoles has been developed. A library of N-substituted 2-aminobenzimidazoles was readily assembled utilizing SNAr reactions, reduction of the nitro group and a one-pot cyclization with isothiocyanate as the key step in the synthesis. The crude benzimidazoles were obtained in 80–99% yields with 78–95% HPLC purity.