3-Ethylsulfanyl-2,5-diphenyl-1-benzofuran

In the title compound, C22H18OS, the 2-phenyl ring is rotated out of the benzofuran plane, making a dihedral angle of 29.18 (6)°. The dihedral angle between the 5-phenyl ring and the benzofuran plane is 20.42 (5)°. In the crystal structure, molecules are linked by weak intermolecular C—H⋯π interactions.

In the title compound, C 22 H 18 OS, the 2-phenyl ring is rotated out of the benzofuran plane, making a dihedral angle of 29.18 (6) . The dihedral angle between the 5-phenyl ring and the benzofuran plane is 20.42 (5) . In the crystal structure, molecules are linked by weak intermolecular C-HÁ Á Á interactions.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: CS2130).
The title compound crystallizes in the monoclinic space group P2 1 . The benzofuran unit is essentially planar, with a mean deviation of 0.020 (1) Å from the least-squares plane defined by the nine constituent atoms. In the molecule, the benzofuran plane makes dihedral angles of 29.18 (6) and 20.42 (5)° with the 2-phenyl ring and the 5-phenyl ring, respectively. The crystal packing (Fig. 2) is stabilized by weak intermolecular C-H···π interactions; the first one between the 5-phenyl H atom and the 5-phenyl ring of an adjacent molecule, with a C10-H10···Cg1 i , and the second one between the 5-phenyl H atom and the 2-phenyl ring of a neighbouring molecule, with a C14-H14···Cg2 ii , respectively (Table 1, Cg1 and Cg2 are the centroids of the C9-C14 phenyl ring and the C15-C20 phenyl ring, respectively, for symmetry operators see Fig. 2

Experimental
Zinc chloride (300 mg, 2.2 mmol) was added to a stirred solution of 4-phenylphenol (375 mg, 2.2 mmol) and 2-chloro-2-(ethylsulfanyl)acetophenone (472 mg, 2.2 mmol) in dichloromethane (30 mL) at room temperature, and stirring was continued at the same temperature for 1hr. The reaction was quenched by the addition of water and the organic layer separated, dried over magnesium sulfate, filtered and concentrated at reduced pressure. The residue was purified by column chromatography (carbon tetrachloride) to afford the title compound as a colorless solid [yield 46%, m.p. 368-369 K; R f = 0.51 (carbon tetrachloride)]. Single crystals suitable for X-ray diffraction were prepared by evaporation of a solution of the title compound in acetone at room temperature.

Refinement
All H atoms were positioned geometrically and refined using a riding model, with C-H = 0.95 Å for aryl, 0.95 Å for methylene and 0.99 Å for methyl H atoms. U iso (H) = 1.2U eq (C) for aryl and methylene, 1.5U eq (C) for methyl H atoms.

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > 2sigma(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.