Process for preparing 4-hydroxy-2-methyl-2H-1,2-benzothiazine-3- N-(2- pyridinyl)carboxamide!-1,1-dioxide, and its phosphoric ester

摘要

The present invention refers to a new process for preparing 4- hydroxy- 2-methyl-2H-1,2-benzothiazine-3- N-(2-pyridinyl)carboxamide!-1,1- dioxide, its phosphoric ester and the obtained phosphoric ester.