N,N′-Bis[(2-methylphenyl)sulfonyl]adipamide

The asymmetric unit of the title compound, C20H24N2O6S2, comprises one half-molecule, the remaining portion being generated via an inversion centre. The dihedral angle between the plane of the benzene ring and the SO2—NH—C(O)—C—C segment is 89.9 (1)°. In the crystal, intermolecular N—H⋯O(S) hydrogen bonds link the molecules into infinite chains in [101].

VZR thanks the University Grants Commission, Government of India, New Delhi, for the award of a research fellowship.

Comment
The sulfonamide moiety is an important constituent of many biologically important compounds. As a part of studying the substituent effects on the structures of this class of compounds (Gowda et al., 2007(Gowda et al., , 2010a, in the present work, the structure of N,N-bis(2-methylphenylsulfonyl)-adipamide has been determined (Fig.1). The asymmetric unit comprises half of a molecule, the remaining portion being generated via an inversion centre. The conformation of the N-H and C=O bonds in the C-SO 2 -NH-C(O)-C-C segment is anti to each other and the amide O atom is also anti to the H atoms attached to the adjacent C atom. Further, the conformation of the N-H bond in the amide fragment is syn to the ortho-methyl group in the adjacent benzene ring. The molecule is bent at the S atom with the C-SO 2 -NH-C(O) torsion angle of -63.7 (4)°.
The dihedral angle between the planes of the benzene ring and the SO 2 -NH-C(O)-C-C segment is 89.9 (1)°. (Table 1)  Experimental N,N-Bis(2-methylphenylsulfonyl)-adipamide was prepared by refluxing a mixture of adipic acid (0.01 mol) with o-toluenesulfonamide (0.02 mol) and POCl 3 for 1 hr on a water bath. The reaction mixture was allowed to cool and added ether to it. The solid product obtained was filtered, washed thoroughly with ether and hot ethanol. The compound was recrystallized to the constant melting point and was characterized by its infrared and NMR spectra.

N-H···O1(S) H-bond formation results in an S=O1 bond longer than the S=O2 bond. A series of N-H···O(S) intermolecular hydrogen bonds
Needle like colorless single crystals used in the X-ray diffraction studies were grown by a slow evaporation of a solution of the compound in ethanol at room temperature.

Refinement
The H atom of the NH group was located in a difference map and later restrained to the distance N-H = 0.86 (2) Å. The other H atoms were positioned with idealized geometry using a riding model with ring C-H distance = 0.93 Å, methylene C-H = 0.97 Å and methyl C-H = 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). as those based on F, and R-factors based on ALL data will be even larger.