N-(3-Chlorophenyl)benzenesulfonamide

In the crystal structure of the title compound, C12H10ClNO2S, the N—H bond is trans to one of the S=O bonds. The two aromatic rings form a dihedral angle of 65.4 (1)°, compared with a value of 49.1 (1)° in N-(2-chlorophenyl)-benzenesulfonamide. The molecules are connected by intermolecular N—H⋯O hydrogen bonds into chains running along the b axis.

In the crystal structure of the title compound, C 12 H 10 ClNO 2 S, the N-H bond is trans to one of the S O bonds. The two aromatic rings form a dihedral angle of 65.4 (1) , compared with a value of 49.1 (1) in N-(2-chlorophenyl)-benzenesulfonamide. The molecules are connected by intermolecular N-HÁ Á ÁO hydrogen bonds into chains running along the b axis.
The packing diagram of N3CPBSA showing the N-H···O hydrogen bonds (Table 1) is shown in Fig. 2.

Experimental
The solution of benzene (10 cc) in chloroform (40 cc) was treated dropwise with chlorosulfonic acid (25 cc) at 273 K.
After the initial evolution of hydrogen chloride subsided, the reaction mixture was brought to room temperature and poured into crushed ice in a beaker. The chloroform layer was separated, washed with cold water and allowed to evaporate slowly.
The residual benzenesulfonylchloride was treated with m-chloroaniline in the stoichiometric ratio and boiled for 10 min.
The reaction mixture was then cooled to room temperature and added to ice cold water (100 cc). The resultant solid N-(3chlorophenyl)-benzenesulfonamide was filtered under suction and washed thoroughly with cold water. It was then recrystallized to constant melting point from dilute ethanol. The purity of the compound was checked and characterized by recording its infrared and NMR spectra (Gowda et al., 2005). Single crystals used in X-ray diffraction studies were grown in an ethanolic solution by evaporating it at room temperature.

Refinement
The H atom of the NH group was located in a difference map and was refined with a N-H distance restraint of 0.90 (1) Å.
The other H atoms were positioned with idealized geometry (C-H = 0.93 Å) and refined using a riding model with U iso (H) = 1.2U eq (C). The U ij components of C4, C5 and C6 were restrained to approximate isotropic behaviour.