2-n-Butyl-6-chloro-1-(2,4-dimethyl-phenyl-sulfon-yl)-1H-benzimidazole-2-n-butyl-5-chloro-1-(2,4-dimethyl-phenyl-sulfon-yl)-1H-benzimidazole (0.759/0.241).

The title compound, 0.759C(19)H(21)ClN(2)O(2)S·0.241C(19)H(21)ClN(2)O(2)S, was synthesized by aryl-sulfonyl-ation of 2-n-butyl-5-chloro-1H-benzimidazole in the presence of triethyl-amine. The crystal structure is composed of two mol-ecules, 2-n-butyl-6-chloro-1-(2,4-dimethylphenyl-sulfon-yl)-1H-benzimidazole and 1-(2,4-dimethylphenyl-sulfon-yl)-2-n-butyl-5-chloro-1H-benz-imidazole, in the refined ratio of 0.759 (4):0.241 (4) disordered at the same position in the unit cell. The mol-ecule has three essentially planar fragments viz. benzimidazole, dimethyl-benzene and n-butyl (r.m.s. deviations of 0.009, 0.024 and 0.003 Å, respectively). The angle between the benzimidazole and dimethyl-benzene fragments is 86.0 (1)°. In the crystal, pairs of inter-molecular C-H⋯π inter-actions form centrosymmetrical dimers, which are linked by weak inter-molecular C-H⋯O hydrogen bonds.