Search

Palladiumcatalyzed amination of 7bromo4methyl2,1,3benzothiadiazole 7 with benzophenone imine as an ammonia equivalent is described as a new, safe and practical alternative to nitration for the synthesis of 7amino4methyl2,1,3benzothiadiazole 1 in high yield. This methodology was successfully scaledup in the pilot plant on 14.0kg scale of 7and was also utilized for the synthesis of 7amino4,6dimethyl2,1,3benzothiadiazole 12 by the amination of 7bromo4,6dimethyl2,1,3benzothiadiazole 10.

Lithiation of Nprotected2,3dihydro1,4benzoxazines is described. Lithiation of Ntertbutoxycarbonyl2,3dihydro1,4benzoxazine 1 with BuLiTMEDA occurred in the αposition to nitrogen on the heterocyclic ring, leading to the unexpected ringopened product 3. On the other hand, lithiation of Nmethyl2,3dihydro1,4benzoxazine 4 took place at the oxygenadjacent orthoposition of the aromatic ring.