Solid-phase synthesis of substituted benzimidazoles

A solid-phase synthesis of benzimidazoles, substituted on the aromatic ring by a variety of groups or atoms, is described. Intermediate 3, derived fro m the acylation of a resin-bound secondary amine with Fmoc-glycine, was ela borated via nucleophilic displacement with substituted o-halonitroarenes to give 4. Careful optimization of the subsequent nitro-group reduction and c yclization with aldehydes, followed by acidolysis gave the title compounds 7 in good yields and purities. (C) 1999 Elsevier Science Ltd. All rights re served.