A convenient synthesis of 1,4-disubstituted imidazoles

An efficient method for the regioselective protection of 4-alkyl-, 4-iodo, 4-vinylimidazoles has been developed via an alkylation–isomerization sequence with various imidazole-protecting groups. The initially formed mixture of 4/5-alkyl-, 4/5-iodo, and 4/5-vinylimidazoles are isomerized to the corresponding 4-isomers on treatment of a DMF solution with a small amount of RX and heating at 75 °C.