Studies on a New Nonsteroidal Antiinflammatory Agent. II. A New Synthetic Method of 2-Substituted-5-benzothiazoleacetic Acids and Their Derivatives

Inhibitors of Adhesion Molecules Expression; The Synthesis and Pharmacological Properties of 10H-Pyrazino[2,3-b][1,4]benzothiazine Derivatives.

“…Compound 2 was synthesized from 4-chloro-3-nitrobenzoic acid 1 by displacement of chloride with sodium disulfide (Na 2 S 2 ), reduction of the nitro group and esterification. 41,42) These intermediates, including aminothiophenol 2, were unstable to purification. The 10H-pyrazino [2,3-b] [1,4]benzothiazine ring was constructed by condensation of 2 with 2,3-dichloropyrazine.…”