Cyanomethyl 4-(4-methylbenzenesulfonamido)benzoate

The title molecule, C16H14N2O4S, adopts an L-shaped conformation, with the central C—S—N—C torsion angle being −69.1 (3)°. The two benzene rings form a dihedral angle of 89.94 (15)°. The molecular conformation may be influenced by a weak intramolecular C—H⋯O hydrogen bond which generates an S(6) ring motif. In the crystal, molecules are linked by N—H⋯O and weak C—H⋯O hydrogen bonds, forming chains propagating along the b axis. Weak C—H⋯N hydrogen bonds connect the chains into a two-dimensional network parallel to (011). The crystal studied was an inversion twin, the ratio of components being 0.7 (1):0.3 (1).

The title molecule exhibits an S(6) motif (Bernstein et al., 1995) formed by a weak intramolecular C-H···O hydrogen bond interaction (Table 1). In the crystal, molecules are linked by N-H···O and weak C-H···O hydrogen bonds forming chains propagating along the b axis. Weak intermolecular C-H···N hydrogen bonds connect the chains into a two dimensional netwok (Table 1, Fig. 2).

Experimental
To an aquious solution of p-amino benzoic acid (1.0 g, 7.3 mmol), sodium carbonate (1 N) was added to adjust the pH to 8. Then p-toluenesulfonyl chloride (1.80 g, 9.48 mmol) was added and the mixture was stirred at room temperature keeping the pH of the mixture at 8.0 with occasional addition of sodium carbonate solution. Progress and completion of the reaction was confirmed by TLC and conversion of the suspension into a clear solution. After 2 h, whole mixture was poured into a beaker and the pH was adjusted to 2.0 by 1 N HCl. Pprecipitates were produced which were filtered and washed with distilled water.
The prepared sulfonamide (4-(Toluene-4-sulfonylamino)-benzoic acid) (1.0 g, 3.43 mmol), DMF (10 ml) and n-hexane washed sodium hydride (0.25 g, 10.31 mmol) were stirred at room temperature for 40 min followed by the addition of chloroacetonitrile (0.34 g, 4.46 mmol). The whole reaction mixture was stirred at 353 K till the completion of the reaction and poured into crushed ice in a beaker. The pH of the mixture was adjusted to 4.0 with 1 N HCl. Precipitates were produced, filtered and washed twice with distilled water. Crystals suitable for X-ray diffraction were grown from a chloroform solution of the title compound.

Refinement
All H atoms were positioned with idealized geometry and were refined using a riding model with U iso (H) = 1.2 or 1.5U eq (C) [N-H = 0.86 Å, C-H = 0.93, 0.96 or 0.97 Å]. One reflection (0 0 2) was omitted from the refinement. The crystal studied is an inversion twin with the refined BASF ratio of 0.70 (10)/0.30 (10).

Figure 1
The molecular structure of (I) with displacement ellipsoids for non-H atoms drawn at the 30% probability level.

Figure 2
View of the packing and hydrogen-bonding interactions in (I) The hydrogen atoms not involved in the hydrogen bonds have been omitted.  (10) Special details Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles Refinement. Refinement on F 2 for ALL reflections except those flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses 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 observed criterion of F 2 > σ(F 2 ) is used only for calculating -R-factor-obs 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.