Abstract By taking advantage of the N, N-diisopropylcarbamoyl moiety as a versatile ortho- directing lithiation group, the preparation of 4, 6-dichloro-and 4, 6-difluorophthalides, starting from the corresponding 3, 5-dihalo-N, N-diisopropylbenzamides, is described here. The role of the lithiating agent, the formation of kinetically and thermodynamically favored products, and the marked difference between the dichloro and difluoro derivatives are discussed in ...
