(1,2,4)Triazino(3,4-c)(1,4)benzothiazin-2(1H)-one, 3,5-dihydro-7-methyl- 139605-57-5 3,5-Dihydro-7-methyl-(1,2,4)triazino(3,4-c)(1,4)benzothiazin-2(1H)-one