1-Arylimidazol-2 (1 H)-ones are shown to be readily lithiated, using 2 mol equiv. of n- butyllithium, on the benzene ring, ortho to the heterocycle. 1-Aryl-4, 5-dihydroimidazol-2 (1 H)-ones also undergo metalation on the aromatic substitutuent ortho to the heterocycle, but less efficiently. 1-Aryl-3-methylimidazol-2 (1 H)-ones are lithiated on the heterocyclic ring and then on the benzene ring ortho to the heterocycle. No ortho-directing effect was found ...
