1-((4,4-Dimethyl-4H-1,3-benzothiazin-2-yl)methyl)-2-pyrrolidinone hydrochloride 2-(2'-Oxopyrrolidino)methyl-4,4-dimethyl-4H-1,3-benzothiazine hydrochloride 2-Pyrrolidinone, 1-((4,4-dimethyl-4H-1,3-benzothiazin-2-yl)methyl)-, hydrochloride 81735-49-1