N-(2-Chlorophenyl)-2-nitrobenzenesulfonamide

In the title compound, C12H9ClN2O4S, the N—H bond in the –SO2—NH– segment is syn to both the ortho-nitro group in the sulfonylbenzene ring and the ortho-Cl atom in the aniline ring. The molecule is twisted at the S—N bond with a torsion angle of 75.0 (2)°. The dihedral angle between the sulfonylbenzene and aniline rings is 54.97 (11)°. The amide H atom shows bifurcated hydrogen bonding, generating S(7) and C(4) motifs. In the crystal, N—H⋯O(S) hydrogen bonds link the molecules into chains.

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: SJ5261).
The conformation of the N-H bond in the -SO 2 -NH-segment is syn to both the ortho-nitro group in the sulfonyl benzene ring and ortho-Cl atom in the anilino ring. similar to that observed in N-(2-chlorobenzoyl)-2-nitrobenzenesulfonamide (I) (Suchetan et al., 2012). The molecule is twisted at the S-N bond with the torsional angle of 74.97 (20)°, compared to the value of -59.68 (17)° in (I).
The dihedral angle between the sulfonyl and the anilino rings is 54.97 (11)°, compared to the value of 71.2 (1)° in (I).
The amide H-atom shows bifurcated intramolecular H-bonding with the O-atom of the ortho-nitro group in the sulfonyl benzene ring and the intermolecular H-bonding with the sulfonyl oxygen atom of the other molecule, generating S(7) and C(4) motifs (Adsmond & Grant 2001;Allen et al., 1998;Bernstein et al., 1995;Etter, 1990).
In the crystal, the intermolecular N-H···O (S) hydrogen bonds (Table 1)

Experimental
The title compound was prepared by treating 2-nitrobenzenesulfonylchloride with 2-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 resulting solid N-(2-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 (145° C) from dilute ethanol. The purity of the compound was checked and characterized by its infrared spectra.
Prism like colourless 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.
The amino H atom was freely refined with the N-H distances restrained to 0.86 (2) Å. All H atoms were refined with isotropic displacement parameters set at 1.2 U eq of the parent atom.  (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.