4,4′-Bis(dimethylamino)benzhydryl phenyl sulfone

In the title compound, C23H26N2O2S, the sulfur-bound phenyl group is aligned approximately parallel to one of the two rings of the benzhydryl group, making a dihedral angle of 1.15 (9)°. The other forms a dihedral angle of 59.20 (9)° with the phenyl group bound to the S atom. In the crystal, molecules are linked into strands along [100] by weak C—H⋯O contacts. Weak C–H⋯π interactions are also observed.

In the title compound, C 23 H 26 N 2 O 2 S, the sulfur-bound phenyl group is aligned approximately parallel to one of the two rings of the benzhydryl group, making a dihedral angle of 1.15 (9) . The other forms a dihedral angle of 59.20 (9) with the phenyl group bound to the S atom. In the crystal, molecules are linked into strands along [100] by weak C-HÁ Á ÁO contacts. Weak C-HÁ Á Á interactions are also observed.
The molecules are linked to strands along [100] by weak contacts of the type C-H···O (Fig. 2). Contacts of this type have been described for a structure of a related sulfone [Li et al. (2005)]. In terms of graph-set analysis [Bernstein et al. (1995), Etter et al. (1990)], the descriptor on the unitary level is C 1 1 (6). Weak C-H···π interactions are also formed (see Table 1 for more details; Cg1 is the centre of gravity of the ring C2 to C7, Cg2 is the centre of gravity of the ring C10 to C15).
Parallel stacking of adjacent phenyl rings is not observed (Fig. 3). The dihedral angles exceed 46° in any cases.

Experimental
The title compound was obtained by mixing sodium benzenesulfinate (36 mg, 0.22 mmol) and 4,4'bis(dimethylamino)benzhydrylium tetrafluoroborate (74 mg, 0.22 mmol) in DMSO (8 ml) at room temperature. After 20 min of stirring, water (10 ml) was added, and the mixture was extracted with ethyl acetate. The organic layer was washed several times with brine and dried (MgSO 4 ). After evaporation of volatile solvents under reduced pressure, 4,4'bis(dimethylamino)benzhydryl phenyl sulfone (42 mg, 48%) was obtained as a colorless solid. A small amount of the solid was dissolved in ethyl acetate. The solvent was allowed to evaporate slowly at room temperature. After 2 days, crystals had formed that were suitable for X-ray analysis. mp 197 °C (mp 204 °C [Hinsberg (1897), Hinsberg (1917)].

Refinement
All H atoms were found in difference maps. C-bound H atoms were positioned geometrically and treated as riding on their parent atoms [U iso (H) = 1.2U eq (C) for CH and U iso (H) = 1.5U eq (C) for CH 3 ].
supplementary materials sup-2 Figures Fig. 1. The molecular structure of the title compound, with atom labels and anisotropic displacement ellipsoids (drawn at 50% probability level) for non-H atoms.