Crystallographic investigations of 1,4-benzothiazin-2(1H)one and 3-methyl-1,4-benzothiazin-2(1H)one

The crystal structures of 1,4-benzothiazin-2(1H)one (C 8 H 7 SNO) ( I ) and 3-methyl-1,4-benzothiazin-2(1H)one (C 9 H 9 SNO) ( II ) have been determined by X-ray diffraction methods. I crystallizes in the monoclinic system with space group P 2 1 / n , while II crystallizes in triclinic with space group P 1̅ . The molecular features in both the structures are almost similar; however, there exists an intermolecular interaction in ( II ) that could be due to the methyl group.