DIRECTED ORTHO METALATION OF N,N-DIETHYL BENZAMIDES - METHODOLOGY AND REGIOSPECIFIC SYNTHESIS OF USEFUL CONTIGUOUSLY TRI-SUBSTITUTED AND TETRA-SUBSTITUTED OXYGENATED AROMATICS, PHTHALIDES AND PHTHALIC ANHYDRIDES

Full experimental details for the directed ortho metalation approach to a variety of simple ortho-substituted NN-diethyl benzamides (Table 1) and contiguously 1,2,3 - and 1,2,3,4-substituted benzamides (Table 2) are given. The efficient conversion of these benzamides (6, 10, 12, 13, 18, 19) into phthalides (9a-b, 16b-c, 17) and phthalic anhydrides (8, 16a), compounds previously available by demanding, classical methods, is detailed. A short synthesis of iso-ochracinic acid (27) is described.