A one-step synthesis of 2,3-dihydro-1,4-benzothiazines and phenothiazines from 1,3-thiazolidine derivatives of cyclohexanones R. Caputo; C. Ferreri; L. Longobardo; D. Mastroianni; G. Palumbo; S. Pedatella

N-Acetyl-1,3-thiazolidine derivatives of cyclohexanones, when treated with a threefold excess N-bromosuccinimide in anhydrous chloroform at room temperature, smoothly afford N-acetyl-2,3-dihydro-1,4-benzothiazines. This represents the first general route to such heterocyclic system in one step from aliphatic precursors. The synthesis of optically active N-acetyl-2,3-dihydro-1,4-benzothiazines is also reporte