N-acetonylsaccharin

2-(3,4-Dimethyl-5,5-dioxo-2H,4H-pyrazolo-[4,3-c][1,2]benzothia-zin-2-yl)-N'-(3-meth-oxy-benzyl-idene)aceto-hydrazide dimethyl-formamide hemisolvate

In the title compound, C(21)H(21)N(5)O(4)S·0.5C(3)H(7)NO, the heterocyclic thia-zine ring adopts a half-chair conformation, with the S and N atoms displaced by -0.451 (5) and 0.233 (5) Å, respectively, from the plane formed by the remaining ring atoms. The asymmetric unit contains a disordered half-mol-ecule of solvent lying close to inversion centers. The crystal structure is stabilized by weak inter-molecular N-H⋯O and C-H⋯O inter-actions.

N'-(2-Chloro-benzyl-idene)-2-(3,4-dimethyl-5,5-dioxo-2H,4H-pyrazolo-[4,3-c][1,2]benzothia-zin-2-yl)acetohydrazide

The asymmetric unit of the title compound, C(20)H(18)ClN(5)O(3)S, contains two independent mol-ecules with significantly different conformations of the heterocyclic thia-zine rings. In both mol-ecules, the thia-zine rings adopt half-chair conformations, with the S atoms displaced by 0.382 (3) and 0.533 (3) Å and N atoms -0.351 and -0.275 Å, respectively, from the planes formed by the remaining ring atoms. The crystal structure is stabilized by weak inter-molecular N-H⋯O and C-H⋯O inter-actions.

N-Saccharinylmethyl ether

In the title mol-ecule [systematic name: 1,1,1',1'-tetra-oxo-2,2'-(oxydimethyl-ene)bi(1,2-benzothia-zol-3-one)], C(16)H(12)N(2)O(7)S(2), the benzisothia-zole ring systems are individually planar [maximum deviations of 0.0497 (13) and 0.0195 (19) Å] and their mean planes are inclined at a dihedral angle of 62.76 (4)°. The crystal structure is stabilized by weak inter-molecular C-H⋯O inter-actions. Two O atoms bonded to two S atoms and four aryl H atoms belonging to two symmetry-related mol-ecules lying about an inversion center form a hydrogen-bonded 10-membered ring with graph-set notation R(4) (2)(10).

2-[2-(3-Chloro-phen-yl)-2-oxoeth-yl]-1,2-benzisothia-zol-3(2H)-one 1,1-dioxide

In the title compound, C₁₅H₁₀ClNO₄S, the benzothia­zole ring system is essentially planar [maximum deviation = 0.0382 (13) Å for the N atom] and forms a dihedral angle of 74.43 (6)° with the chloro-substituted benzene ring. In the crystal structure, weak inter­molecular C—H⋯O hydrogen bonds form R₂²(10) and R₂²(16) ring motifs

2-(2-Oxo-2-phenyl-ethyl)-1,2-benziso-thia-zol-3(2H)-one 1,1-dioxide

In the title compound, C₁₅H₁₁NO₄S, the benzothia­zole unit is essentially planar [maximum deviation = 0.0644 (14) Å for the N atom] and forms a dihedral angle 54.43 (6)° with the phenyl ring. In the crystal structure, weak bifurcated C—H⋯O hydrogen bonds involving the carbonyl O atoms as acceptors result in R₂²(7) ring motifs.

2-[2-(3-Methoxy-phen-yl)-2-oxoeth-yl]-1,2-benzisothia-zol-3(2H)-one 1,1-dioxide

In the title compound, C(16)H(13)NO(5)S, the benzothia-zole unit is essentially planar [maximum deviation = 0.0501 (10) Å for the S atom] and is oriented at a dihedral angle of 67.85 (5)° with respect to the meth-oxy-substituted benzene ring. The mean plane of the meth-oxy group is oriented at 14.3 (3)° with respect to the benzene ring to which it is attached. In the crystal structure, weak C-H⋯O hydrogen bonds form macrocyclic rings with R(2) (2)(10) and R(2) (2)(12) motifs.