N-(3,4-Dimethylphenyl)benzenesulfonamide

The structure of the title compound, C14H15NO2S, shows the sulfonamide N atom to be approximately perpendicular to the plane through the S-bound benzene ring [the N—S—C—C torsion angle is −87.4 (3)°] and to lie to the opposide side of this ring to the two sulfonamide O atoms. The N-bound benzene ring is splayed out with respect to the rest of the molecule so that overall, the molecule adopts a twisted conformation. The dihedral angle between the two benzene rings is 64.5 (3)°. In the crystal, supramolecular chains aligned along the b axis are formed via N—H⋯O hydrogen bonds.

The structure of the title compound, C 14 H 15 NO 2 S, shows the sulfonamide N atom to be approximately perpendicular to the plane through the S-bound benzene ring [the N-S-C-C torsion angle is À87.4 (3) ] and to lie to the opposide side of this ring to the two sulfonamide O atoms. The N-bound benzene ring is splayed out with respect to the rest of the molecule so that overall, the molecule adopts a twisted conformation. The dihedral angle between the two benzene rings is 64.5 (3) . In the crystal, supramolecular chains aligned along the b axis are formed via N-HÁ Á ÁO hydrogen bonds.
We are grateful to Mr Munawar Hussain, Engineering Cell GC University, Lahore, for providing support services to the Materials Chemistry Laboratory.

Comment
In continuation of on-going structural studies of sulfonamides (Khan et al., 2010;Sharif et al., 2010), of interest owing to their putative anti-microbial activity (Korolkovas, 1988;Mandell & Sande, 1992), the crystal and molecular structure of the title compound, (I), was investigated.
In (I), both sulfonamido-O atoms lie to one side of the S-bound benzene ring [the O1-S1-C1-C6 and O2-S1-C1-C2 torsion angles are 19.3 (4) and -28.0 (3) °, respectively] and are on the opposite side of this ring to the sulfonamido-N1 atom, Fig. 1. The latter is approximately perpendicular to the benzene ring [N1-S1-C1-C2 is -87.4 (3) °] with the N-bound benzene ring clearly displaced to one side of the molecule; the dihedral angle formed between the two benzene rings is 64.5 (3) °. Although not isomorphous, the overall molecular conformation found in the closely related derivative, with an S-bound tolsyl group, is almost identical (Gowda et al. 2009).
The presence of N1-H···O2 hydrogen bonding, Table 1, leads to the formation of supramolecular chains along the b axis, Fig. 2.

Experimental
To 3,4-dimethyl aniline (484 mg, 4 mmol) in distilled water (10 ml) was added benzene sulfonyl chloride (510 ml, 4 mmol) with stirring at room temperature while maintaining the pH of the reaction mixture at 8 using 3% sodium carbonate. The progress of the reaction was monitored by TLC. The precipitate formed was washed with water, dried and crystallized from a methanol/ethyl acetate mixture (50:50 V/V) to yield colourless prisms of (I); m. pt 414 K.

Refinement
The C-bound H atoms were geometrically placed (C-H = 0.93-0.96 Å) and refined as riding with U iso (H) = 1.2U eq (C). The N-bound H atom was refined with the distance restraint N-H = 0.86±0.01 Å, and with U iso (H) = 1.2U eq (N). High thermal motion was noted for several atoms in the S-bound benzene ring but multiple positions were not resolved. The anisotropic displacement parameters for this ring were refined with the ISOR command to constrain these to be approximately isotropic.
supplementary materials sup-2 Figures   Fig. 1. The molecular structure of (I) showing displacement ellipsoids at the 35% probability level.

Special details
Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The 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 > 2σ(F 2 ) is used only for calculating Rfactors(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.