AN IMPROVED PROCESS FOR THE PREPARATION OF 3,4-DIHYDRO-1,4-BENZOTHIAZINE

摘要

A process for the preparation of 3,4-dihydro-1,4-benozthiazine of the formula (1) which comprises, condensing of 2-aminothiophenol with dihaloethane of formula (11) wherein X represents halogen atom in presence of organic base and relatively non polar solvent at a temperature in the range of 40-80 DEG C followed by cyclization and formation of organic salt as by product and isolating the compound of formula (1) by conventional methods.