N-(4-Chlorophenyl)-2-nitrobenzenesulfonamide

In the title compound, C12H9ClN2O4S, the dihedral angle between the aromatic rings is 70.27 (8)°. In the crystal, molecules are linked by pairs of N—H⋯O(S) hydrogen bonds, forming 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: BT5983).
The conformation of the N-H bond in the -SO 2 -NH-segment is syn to the ortho-nitro group in the sulfonyl benzene ring, similar to that observed in N-(phenyl)-2-nitrobenzenesulfonamide (I) (Chaithanya et al., 2012). The molecule is twisted at the S-N bond with the torsional angle of 79.17 (18)°, compared to the value of -72.83 (15)° in (I).
The dihedral angle between the sulfonyl and the anilino rings is 70.27 (8)°, compared to the value of 59.55 (7)° in (I).
In the crystal, the pairs of intermolecular N-H···O (S) hydrogen bonds (Table 1) link the molecules into inversion dimers. Part of the crystal structure is shown in Fig. 2.

Experimental
The title compound was prepared by treating 2-nitrobenzenesulfonylchloride with 4-chloroaniline 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-(4-chlorophenyl)-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 yellow 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 C-H = 0.93 Å. The coordinates of the amino H atom were refined with the N-H distance restrained to 0.86 (1) Å. All H atoms were refined with isotropic displacement parameters set to 1.2 U eq of the parent atom. The (0 1 2 and 0 3 3) reflections were probably affected by the beamstop and were omitted from the refinement.

Computing details
Data collection: CrysAlis CCD (Oxford Diffraction, 2009); cell refinement: CrysAlis CCD (Oxford Diffraction, 2009); data reduction: CrysAlis RED (Oxford Diffraction, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).   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.