Halogenated (acylamino) imidazoles and benzimidazoles for directed halogen-metal exchange-based functionalization

Regioselective syntheses of 4- and 5-(acylamino)-1-alkylimidazoles bearing an ortho-halogen atom have been developed. Suitable for use in ortho-direct ed halogen-metal exchange-mediated ring functionalizations, these compounds are valuable precursors to ortho-functionalized versions of biologically a ctive 4- and 5-aminoimidazoles. To widen the scope of this approach to cove r similarly-substituted benzimidazoles and their potentially bioactive nucl eosides, the synthesis of halogenated 5- and 6-(acylamino)-benzimidazoles a nd their ribosides was also explored.