Synthesis of structurally diverse benzimidazolyl benzimidazolones by application of soluble polymer support

Chemical stability and reactivity of a bifunctional polymer conjugate containing an ortho-amino arylamide linkage have been successfully exploited to achieve a parallel synthesis of methoxycarbonylated head–tail bis-benzimidazoles. Regioselective alkylation of the two nitrogens in the benzimidazolone moiety has been carried out by ipso-fluoro displacement, and N-alkylation to generate two diversities. Cleavage of the polymer support has resulted in two libraries of di- and tri-substituted benzimidazolyl benzimidazolones in high purity and high yield. All reaction steps have been monitored by 1H NMR on the support directly.