Chemoenzymatic synthesis of stannylated metomidate as a precursor for electrophilic radiohalogenations - Regioselective alkylation of methyl 1H-imidazole-5-carboxylate [1]

Abstract

Metomidate (ee 99%) substituted with iodine in the phenyl ring was prepared from (S)-1-(4-iodophenyl)ethanol (ee >98%) obtained by lipase-catalysed resolution and methyl 1H-imidazole-5-carboxylate. The two fragments were joined highly regioselectively (alkylation only at N-1 of substituted imidazole) with inversion of configuration using the Mitsunobu reaction. Finally, p-iodometomidate was transformed into the p-trimethylstannyl derivative. © Springer-Verlag 2004.