A solution of 1b in acetonitrile in

A solution of 1b in acetonitrile in a microwave glass vial equipped with a stir bar was treated with the amine at room temperature until complete decoloration of the solution. The aldehyde was added, and the vessel with the resulting light-yellow mixture was sealed and heated under microwave irradiationat 150 °C for 20 min. The solvent was evaporated under reduced pressure, and the crude residue was purified by column chromatography to yield the desired imidazole-4-carboxylate.