N-(2,5-Dimethylphenyl)-2-nitrobenzenesulfonamide

In the crystal structure of the title compound, C14H14N2O4S, the N—H bond is syn to the ortho-nitro group in the sulfonyl benzene ring and anti to the ortho- and syn to the meta-methyl groups in the aniline ring. The molecule is twisted at the S—N bond with a torsion angle of 71.41 (18)°. The dihedral angle between the planes of the benzene rings is 51.07 (8)°. In the crystal, pairs of N—H⋯Osulfonamide hydrogen bonds link the molecules into inversion dimers.

In the crystal structure of the title compound, C 14 H 14 N 2 O 4 S, the N-H bond is syn to the ortho-nitro group in the sulfonyl benzene ring and anti to the ortho-and syn to the meta-methyl groups in the aniline ring. The molecule is twisted at the S-N bond with a torsion angle of 71.41 (18) . The dihedral angle between the planes of the benzene rings is 51.07 (8) . In the crystal, pairs of N-HÁ Á ÁO sulfonamide hydrogen bonds link the molecules into inversion dimers.
BTG thanks the University Grants Commission, Government of India, New Delhi, for a special grant under the UGC-BSR one-time grant to faculty.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: RZ5026). As a part of studying the effect of substituents on the structures and other aspects of N-arylsulfonamides (Chaithanya et al., 2012;Gowda et al., 2002) and N-chloroarylsulfonamides , in the present work, the crystal structure of N-(2,5-dimethylphenyl)-2-nitrobenzene-sulfonamide (I) has been determined ( Fig.   1). The conformation of the N-H bond is syn to the ortho-nitro group in the sulfonyl benzene ring and anti to the orthomethyl and syn to the meta-methyl groups in the anilino ring, compared to the anti conformation observed between the N -H bond and both the ortho-and meta-methyl groups in the anilino ring observed in N-(2,3-dimethylphenyl)-2-nitrobenzene-sulfonamide (II) (Chaithanya et al., 2012).
The molecules in (I) are twisted at the S-N bond with the torsional angle of 71.41 (18)°, compared to the values of -60.37 (30) and 58.81 (34)° in the two independent molecules of (II).
The dihedral angle between the sulfonyl and the anilino rings is 51.07 (8)°, compared to the values of 53.67 (8) and 56.99 (9)° in the two molecules of (II).
The amide H-atom showed the intermolecular H-bonding with the sulfonyl oxygen atom of the other molecule, generating inversion dimers (Table 1, Fig. 2

Experimental
The title compound was prepared by treating 2-nitrobenzenesulfonyl-chloride with 2,5-dimethylaniline in the stoichiometric ratio and boiling the reaction mixture for 15 minutes. The reaction mixture was then cooled to room temperature and added to ice cold water (100 ml). The resultant solid N-(2,5-dimethylphenyl)-2-nitrobenzenesulfonamide was filtered under suction and washed thoroughly with cold water and dilute HCl to remove the excess sulfonylchloride and aniline, respectively. It was then recrystallized to constant melting point from dilute ethanol. The purity of the compound was checked and characterized by its infrared spectra.
Prism like light brown single crystals of the title compound used in X-ray diffraction studies were grown in ethanolic solution by slow evaporation of the solvent at room temperature.

Refinement
H atoms bonded to C were positioned with idealized geometry using a riding model with the aromatic C-H = 0.93 Å, methyl C-H = 0.96 Å. The amino H atoms were freely refined with the N-H distance restrained to 0.86 (2) Å. All H atoms were refined with isotropic displacement parameters set at 1.2 U eq (C-aromatic, N) and 1.5 U eq (C-methyl) of the parent atom. The (0 1 1) reflection is probably affected by the beamstop and was omitted from the refinement.

N-(2,5-Dimethylphenyl)-2-nitrobenzenesulfonamide
Crystal data C 14 H 14 N 2 O 4 S M r = 306.33 Triclinic, P1 Hall symbol: -P 1 a = 8.1987 (7) Å b = 9.6729 (9) Å c = 9.9328 (9) Å α = 84.386 (9)  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.