N-[4-(p-Toluenesulfonamido)phenylsulfonyl]acetamide

In the title compound, C15H16N2O5S2, the dihedral between the two aromatic rings is 81.33 (6)°. In the crystal, pairs of N—H⋯O hydrogen bonds link the molecules into centrosymmetric dimers, which are further connected via N—H⋯O hydrogen bonds into a chain running along [01].

In the title compound, C 15 H 16 N 2 O 5 S 2 , the dihedral between the two aromatic rings is 81.33 (6) . In the crystal, pairs of N-HÁ Á ÁO hydrogen bonds link the molecules into centrosymmetric dimers, which are further connected via N-HÁ Á ÁO hydrogen bonds into a chain running along [101].

Experimental
The title compound was prepared using a literature method (Deng & Mani, 2006). Sodium sulphacetamide (2 g, 9.3 mmol) was dissolved in distilled water, and then toluene sulfonyl chloride (1.77 g, 9.3 mmol) was added with stirring at room temperature. The pH was maintained at 8-9, strictly using Na2CO3 (1 M). The completion of reaction was observed by the consumption of the suspended toluene sulfonyl chloride. On completion, pH was adjusted to 2-3 using HCl (2 N). The precipitate formed was filtered, washed with distilled water and recrystalyzed from methanol.

Refinement
The H-atoms bonded to C were positioned geometrically and refined using a riding model with C-H = 0.93 Å, U(H) = 1.2 U eq (C) for aromatic and C-H = 0.96 Å for CH 3 , U(H) = 1.5 U eq (C) for CH 3 . The N-H H atoms were located in difference map and their coordinates were refined with U(H) = 1.2 U eq (N) for N atoms.

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 > 2sigma(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.