foerfarande foer framstaellning of pharmaceutical anvaendbar 2 - methyl - 4 - hydroxy - 2h - 1,2 - bensotiazin 1,1-dioxide - 3 - (n - 2-pyridyl) n-methyl-2-pyridone-5-carboxamide

摘要

This invention relates to a method for the preparation of a pharmaceutically usable 2-methyl-4-hydroxy-2H-1,2-benzothiazine-1,1-dioxide with formula I IMG I In accordance with the invention 2-methyl-4-mesyloxy-2H,1,2-benzothiazine-1,1-dioxide-3-carboxylic acid with formula II IMG II is reacted with 2-aminopyridine in the presence of thionyl chloride in an inert solvent. The invention relates also to the intermediate with formula II which can be used in the method.