2-Methyl-N-(4-methylbenzoyl)benzenesulfonamide

The asymmetric unit of the title compound, C15H15NO3S, contains two independent molecules. The conformations of the N—C bonds in the C—SO2—NH—C(O) segments have gauche torsions with respect to the SO bonds. Further, the molecules are twisted at the S atoms with torsion angles of −53.1 (2) and 61.2 (2)° in the two molecules. The dihedral angles between the sulfonyl benzene rings and the —SO2—NH—C—O segments are 86.0 (1) and 87.9 (1)°. Furthermore, the dihedral angles between the sulfonyl and the benzoyl benzene rings are 88.1 (1) and 83.5 (1)° in the two molecules. In the crystal, molecules are linked by N—H⋯O(S) hydrogen bonds.

The asymmetric unit of the title compound, C 15 H 15 NO 3 S, contains two independent molecules. The conformations of the N-C bonds in the C-SO 2 -NH-C(O) segments have gauche torsions with respect to the SO bonds. Further, the molecules are twisted at the S atoms with torsion angles of À53.1 (2) and 61.2 (2) in the two molecules. The dihedral angles between the sulfonyl benzene rings and the -SO 2 -NH-C-O segments are 86.0 (1) and 87.9 (1) . Furthermore, the dihedral angles between the sulfonyl and the benzoyl benzene rings are 88.1 (1) and 83.5 (1) in the two molecules. In the crystal, molecules are linked by N-HÁ Á ÁO(S) hydrogen bonds.

Comment
Diaryl acylsulfonamides are known as potent antitumor agents against a broad spectrum of human tumor xenografts in nude mice. As a part of studying the effect of ring and the side chain substituents on the crystal structures of N-aromatic sulfonamides (Gowda et al., 2009;2010;Suchetan et al., 2010), the structure of 2-methyl-N-(4-methylbenzoyl)benzenesulfonamide (I) has been determined. The asymmetric unit of the structure contains two independent molecules (Fig. 1). The conforma-  (Table 1) is shown in Fig. 2.

Experimental
The title compound was prepared by refluxing a mixture of 4-methylbenzoic acid, 2-methylbenzenesulfonamide and phosphorous oxy chloride for 5 h on a water bath. The resultant mixture was cooled and poured into ice cold water. The solid, 2methyl-N-(4-methylbenzoyl)benzenesulfonamide obtained was filtered, washed thoroughly with water and then dissolved in sodium bicarbonate solution. The compound was later reprecipitated by acidifying the filtered solution with dilute HCl. The filtered and dried compound was recrystallized to the constant melting point. Plate like colorless single crystals of the title compound used in X-ray diffraction studies were grown from a slow evaporation of its toluene solution at room temperature.

Refinement
The H atoms of the NH groups were located in a difference map and later restrained to N-H = 0.86 (2) %A. The other H atoms were positioned with idealized geometry using a riding model with C-H = 0.93-0.96 Å All H atoms were refined with isotropic displacement parameters (set to 1.2 times of the U eq of the parent atom). Fig. 1. Molecular structure of the title compound, showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level.

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
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 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.