3-(4-Fluorophenylsulfinyl)-2,5-dimethyl-1-benzofuran

In the title compound, C16H13FO2S, the O atom and the 4-fluorophenyl group of the 4-fluorophenylsulfinyl substituent are located on opposite sides of the plane through the benzofuran fragment; the 4-fluorophenyl ring is nearly perpendicular to this plane, making a dihedral angle of 87.41 (3). The crystal structure exhibits a weak intermolecular C—H⋯O hydrogen bond.

In the title compound, C 16 H 13 FO 2 S, the O atom and the 4fluorophenyl group of the 4-fluorophenylsulfinyl substituent are located on opposite sides of the plane through the benzofuran fragment; the 4-fluorophenyl ring is nearly perpendicular to this plane, making a dihedral angle of 87.41 (3). The crystal structure exhibits a weak intermolecular C-HÁ Á ÁO hydrogen bond.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: FK2012).
The benzofuran unit is essentially planar, with a mean deviation of 0.009 (1) ° from the least-squares plane defined by the nine constituent atoms. The 4-fluorophenyl ring is almost perpendicular to the plane of the benzofuran fragment [87.41 (3)°] and is tilted slightly towards it. The crystal packing ( Fig. 2) is stabilized by a weak intermolecular C-H···O hydrogen bond between the methyl H atom and the oxygen of the S═O unit, with a C10-H10B···O2 i (Table 1).
Experimental 77% 3-Chloroperoxybenzoic acid (291 mg, 1.3 mmol) was added in small portions to a stirred solution of 3-(4-fluorophenylsulfanyl)-2,5-dimethyl-1-benzofuran (326 mg, 1.2 mmol) in dichloromethane (30 mL) at 273 K. After being stirred at room temperature for 3h, the mixture was washed with saturated sodium bicarbonate solution and the organic layer was separated, dried over magnesium sulfate, filtered and concentrated in vacuum. The residue was purified by column chromatography (hexane-ethyl acetate, 1:1 v/v) to afford the title compound as a colorless solid [yield 80%, m.p. 420-421 K; R f = 0.69 (hexane-ethyl acetate, 1:1 v/v)]. Single crystals suitable for X-ray diffraction were prepared by slow evaporation of a solution of the title compound in ethyl acetate at room temperature.

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.