N,N′-Bis(4-chlorophenylsulfonyl)suberamide

The asymmetric unit of the title compound, C20H22Cl2N2O6S2, contains one half-molecule with a center of symmetry at the mid-point of the central C—C bond. The conformations of all the N—H, C=O and C—H bonds in the central amide and aliphatic segments are anti to their adjacent bonds. The molecule is bent at the S atom with a C—SO2—NH—C(O) torsion angle of −80.6 (4)°. The dihedral angle between the benzene ring and the SO2—NH—C(O)—CH2—CH2—CH2 segment is 79.5 (2)°. In the crystal, intermolecular N—H⋯O(C) and N—H⋯O(S) hydrogen bonds link the molecules into chains along the b axis.

VZR thanks the University Grants Commission, Government of India, New Delhi, for the award of a research fellowship.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: SJ6195).
The dihedral angle between the benzene ring and the SO 2 -NH-C(O)-CH 2 -CH 2 -CH 2 segment in the two halves of the molecule is 79.5 (2)°, compared to the values of 77.5 (1)° in (II) and 89.6 (2)° in (III).
The structure shows simultaneous of N-H···O(C) and N-H···O(S) intermolecular hydrogen bonds (Table 1), which link the molecules into infinite chains along the b-axis.
Experimental N,N-Bis(4-chlorophenylsulfonyl)-suberamide was prepared by refluxing a mixture of suberic acid (octanedioic acid) (0.01 mol) with 4-chlorobenzenesulfonamide (0.02 mol) and POCl 3 for 1 hr on a water bath. The reaction mixture was allowed to cool and ether added to it. The solid product was filtered and washed thoroughly with ether and hot ethanol. The compound was recrystallized to the constant melting point and characterized by its infrared and NMR spectra.
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.