The intermediate 2-methyl-4-mesyloxy-2H-1,2-benzothiazine- 1,1-dioxide-3-carboxylic acid, or a solvate thereof with dimethylacetamide, for use in preparing a pharmaceutically utilizable benzothiazine dioxide

摘要

The present invention relates to an intermediate for preparing a pharmaceutically utilizable 2-methyl-4- hydroxy-2H-1,2-benzothiazine-1,1-dioxin of the formula I The intermediate consists of 2-methyl-4-mesyloxy-2H-1,2- benzothiazine-1,1-dioxide-3-carboxylic acid of the formula II