2,5-Dichloro-N-(2,3-dimethylphenyl)benzenesulfonamide

In the title compound, C14H13Cl2NO2S, the dihedral angle between the aromatic rings is 62.21 (7)° and the C—S—N—C group adopts a gauche conformation [torsion angle = 60.22 (17)°]. In the crystal, N—H⋯O hydrogen bonds link the molecules into C(4) chains propagating in [010]. A short intermolecular Cl⋯O contact of 3.1115 (17) Å is seen.

In the title compound, C 14 H 13 Cl 2 NO 2 S, the dihedral angle between the aromatic rings is 62.21 (7) and the C-S-N-C group adopts a gauche conformation [torsion angle = 60.22 (17) ]. In the crystal, N-HÁ Á ÁO hydrogen bonds link the molecules into C(4) chains propagating in [010]. A short intermolecular ClÁ Á ÁO contact of 3.1115 (17) Å is seen.
Experimental 0.1 g of 2,3 dimethyl aniline was dissolved in 15 ml dichloromethane and 0.2 g of 2,5-dichloro benzene sulfonylchloride was added: the mixture was stirred at room temperature overnight with the pH maintained at 8-9 with triethyamine. On completion of reaction (after TLC) the mixture was poured into a separating flask and 1 M HCl solution added. The lower DCM layer was separated and the solvent was allowed to evaporate at room temperature. Brown blocks of (I) were recrystallized from acetonitrile solution at room temperature in 96% yield.

Refinement
The N-bond H atom was located in a difference map and its position was freely refined. The C-bound H atoms were placed in calculated positions (C-H = 0.93-0.97 Å) and refined as riding. The constraint U iso (H) = 1.2U eq (C,N) or 1.5U eq (methyl C) was applied. The methyl groups were allowed to rotate, but not to tip, to best fit the electron density.

Figure 1
The molecular structure of (I), showing displacement ellipsoids at the 50% probability level.

Figure 2
Fragment of a C(4) chain in the crystal of (I), with N-H···O hydrogen bonds shown as double-dashed lines. All C-bound H atoms omitted for clarity. Symmetry code: (i) 1/2 -x, y + 1/2, z. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.