An efficient route to 5-iodo-1-methylimidazole: synthesis of xestomanzamine A

An efficient and practical route to C-5 functionalized N-methylated imidazo les is reported. 5-Iodo-1-methylimidazole was synthesized in four steps fro m imidazole, with complete regiospecificity, in 73% overall yield. The synt hesis of xestomanzamine A, a marine natural product isolated in 1995 from a n Okinawan sponge of Xestospongia sp., has been achieved using 5-iodo-1-met hylimidazole in a modified Grignard reaction with a beta -carboline ester m oiety, in an overall yield of 59% based upon imidazole and 53% based upon t ryptamine.