Propyl 2-(4-methylbenzenesulfonamido)benzoate

In the title compound, C17H19NO4S, the terminal ethyl group is disordered over two sets of sites, with refined site occupancies of 0.536 (7) and 0.464 (7). The dihedral angle between the two aromatic rings is 81.92 (12)°. The molecular conformation is stabilized by intramolecular N—H⋯O and C—H⋯O hydrogen bonds, which generate S(6) motifs. In the crystal, molecules are linked by C—H⋯O hydrogen bonds, forming chains along the b axis.

In the title compound, C 17 H 19 NO 4 S, the terminal ethyl group is disordered over two sets of sites, with refined site occupancies of 0.536 (7) and 0.464 (7). The dihedral angle between the two aromatic rings is 81.92 (12) . The molecular conformation is stabilized by intramolecular N-HÁ Á ÁO and C-HÁ Á ÁO hydrogen bonds, which generate S(6) motifs. In the crystal, molecules are linked by C-HÁ Á ÁO hydrogen bonds, forming chains along the b axis.
The molecular conformation of (I) is stabilized by intramolecular N-H···O and C-H···O hydrogen-bond interactions, generating S(6) motifs (Table 1). The crystal structure is stabilized by C-H···O hydrogen bonds, forming chains along the b axis (Table 1, Fig. 2).

Experimental
To an aqueous solution of o-amino benzoic acid (1.0 g, 7.3 mmol), sodium carbonate (1 N) was added to adjust the pH 8.
Then p-toluenesulfonyl chloride (1.80 g, 9.48 mmol) was added and the mixture stirred at room temperature keeping the pH of the mixture up to 8.0 with occasional addition of sodium carbonate solution. Progress and completion of the reaction was confirmed by TLC and conversion of suspension into clear solution. After 2 h, whole mixture was poured into a beaker and the pH was adjusted to 2.0 by 1 N HCl. Precipitates were produced which were filtered and washed with distilled water.
The prepared sulfonamide (2-(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 propyl iodide (0.76 g, 4.56 mmol). The whole reaction mixture was stirred 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, washed twice with distilled water and crystallized in chloroform.

Figure 1
The molecular structure of (I) with the atom numbering scheme. Displacement ellipsoids for non-H atoms are drawn at the 30% probability level. Only the atoms of major disorder component are shown.  View of the hydrogen-bonding interactions of (I) along the c axis in the unit cell. Only the hydrogen atoms involved in hydrogen bonds (dotted lines) are drawn, for clarity. where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.41 e Å −3 Δρ min = −0.37 e Å −3 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.