Abstract An improved, 3-step synthesis of 3, 4-dihydro-1-methyl-1H-2, 1-benzothiazin-4-one 2, 2-dioxide has been developed. This general method offers a more facile entrance into the 2, 1-benzothiazine 2, 2-dioxide heterocyclic system than was heretofore available. Preparation of several 3-carbox-anilides was accomplished by interaction of this ring system with various isocyanates. The resulting carboxanilides are moderately strong, enolic acids.
