4-(3-Methylbenzenesulfonamido)phenyl 3-methylbenzenesulfonate

The complete molecule of the title compound, C20H19NO5S2, is generated by a crystallographic twofold axis and the O atom and N—H group attached to the central benzene ring are statistically disordered. The dihedral angle between the central and terminal benzene rings is 56.91 (5)° and that between the terminal benzene rings is 29.80 (5)°. In the crystal, N—H⋯O hydrogen bonding links the molecules into sheets lying parallel to the ab plane.

The complete molecule of the title compound, C 20 H 19 NO 5 S 2 , is generated by a crystallographic twofold axis and the O atom and N-H group attached to the central benzene ring are statistically disordered. The dihedral angle between the central and terminal benzene rings is 56.91 (5) and that between the terminal benzene rings is 29.80 (5) . In the crystal, N-HÁ Á ÁO hydrogen bonding links the molecules into sheets lying parallel to the ab plane.

Related literature
For the biological properties of sulfonyl derivatives, see: Supuran et al. (2003). For a related structure, see: Sinha et al. (2011). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 Table 1 Hydrogen-bond geometry (Å , ).

Comment
Sulfonyl compounds have attracted our interest and many others, due to their varied biological activities (Sinha et al., 2011).
Sulfonyl derivatives are found to be active against inflammation, various viral infections as well as cancer (Supuran et al., 2003).
The asymmetric unit of the title compound consists of half the molecule with the other half of the molecule being generated by a twofold axis. The crystal structure is disordered with the O1 and the N1 atoms attached at the same position with half occupancies each to the central phenyl ring (Fig 1 and Fig 2). All parameters in (I) are within normal ranges. The dihedral angle between C1/C6 and C8-C12/C8a-C12a is 56.91 (5)° whereas the dihedral angle between C1-C6 and C1a-C6a is 29.80 (5)°. In the crystal structure, (Fig. 3), N1-H1···O3 i hydrogen bonds (Table 1) link the molecules into infinite layers parallel to ab-plane.
Experimental 0.02 mole of m-toluenesulfonyl chloride was added to 0.01 mole of p-aminophenol dissolved in pyridine. The reaction mixture was then neutralized by adding hydrochloric acid. The precipitate formed was dissolved in 5% aqueous sodium hydroxide and the sulfonamide recovered by adding 1:1 hydrochloric acid slowly. Re-crystallization of the product by ethanol gave colourless blocks of the title compound.

Refinement
N bound H atom is located from a difference Fourier maps and refined using a riding model. The remaining H atoms were positioned geometrically and refined using a riding model with C-H = 0.93-0.96Å and U iso (H) = 1.2 or 1.5 U eq (C-methyl). A rotating group model was applied to the methyl groups. The crystal structure is disordered with N1 and O1 occupying the same phenyl position with refined site of occupancies closed to 0.5. In the final refinement, the ratio was fixed at half occupancy. Fig. 1. A disorder component of the structure with 50% probability displacement ellipsoids. Hydrogen atoms are shown as spheres of arbitrary radius.

Special details
Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K. as those based on F, and R-factors based on ALL data will be even larger.