N,N′-Bis(3-methylbut-2-enyl)-N,N′-(1,4-phenylene)dibenzenesulfonamide

The complete molecule of the title compound, C28H32N2O4S2, is generated by a crystallographic inversion centre. The dihedral angle between the central and pendant aromatic rings is 46.78 (7)°. The Car—S—N—Car (ar = aromatic) torsion angle is 73.64 (15)° and the bond-angle sum for the N atom is 350.4°. In the crystal, weak C—H⋯O interactions link the molecules, forming a two-dimensional network lying parallel to the bc plane.

The complete molecule of the title compound, C 28 H 32 N 2 O 4 S 2 , is generated by a crystallographic inversion centre. The dihedral angle between the central and pendant aromatic rings is 46.78 (7) . The C ar -S-N-C ar (ar = aromatic) torsion angle is 73.64 (15) and the bond-angle sum for the N atom is 350.4 . In the crystal, weak C-HÁ Á ÁO interactions link the molecules, forming a two-dimensional network lying parallel to the bc plane.   Table 1 Hydrogen-bond geometry (Å , ).
IUK thanks the Higher Education Commission of Pakistan for its financial support under the project to strengthen the Materials Chemistry Laboratory at GCUL.

Comment
As part of our ongoing studies of symmetrical aryl sulfonamides (Ejaz et al., 2011a,b), the synthesis and structure of the title compound are described herein.
The complete molecule of the title compound is generated by a crystallographic inversion centre (Fig. 1). The dihedral angles between the central benzene ring (C12-C17) and the pendant (C1-C6) ring is 46.78 (7)°. Overall, an approximante H-shaped conformation arises. The C1-S1-N1-C12 torsion angle is 73.64 (15)°, indicating a gauche conformation for the sulfonamide bridge between the aromatic rings. The bond angle sum of 350.4° for the nitrogen atom, N1, is similar to the situation found for two related structures, N, N'-(benzene-1,3-diyldimethanediyl) In the crystal, weak C-H···O interactions link the molecules to form a two-dimensional network lieing parallel to the bc plane (Table 1). There is no aromatic π-π stacking in the crystal.

Experimental
A mixture of N,N'-benzene-1,4-diyldibenzenesulfonamide (0.194 g, 0.5 mmol), sodium hydride (0.24 g; 1.0 mmol) and N,N-dimethylformamide (10.0 ml) was stirred in a 100-ml round-bottom flask at room temperature for half an hour followed by the addition of 3,3-dimethylallyl bromide (0.116 ml; 1.0 mmol). The reaction mixture was stirred for five hours; reaction progress was monitored by TLC. After completion, the contents were poured over crushed ice. The precipitated product was isolated, washed and crystallized from methanol to yield brown block-like crystals of the title compound.