24683-26-9 2H-1,2-Benzothiazine-3-carboxylic acid, 4-hydroxy-2-methyl-, ethyl ester, 1,1-dioxide EINECS 246-403-7 Ethyl 4-hydroxy-2-methyl-2H-1,2-benzothiazine-3-carboxylate 1,1-dioxide