1-((4,4-Dimethyl-4H-1,3-benzothiazin-2-yl)methyl)-3-phenyl-2-piperazinone oxalate 2-(2'-Oxo-3'-phenylpiperazino)methyl-4,4-dimethyl-4H-1,3-benzothiazine oxalate 2-Piperazinone, 1-((4,4-dimethyl-4H-1,3-benzothiazin-2-yl)methyl)-3-phenyl-, oxalate 81735-48-0