5-Fluoro-3-methylsulfinyl-2-phenyl-1-benzofuran

In the title compound, C15H11FO2S, the O atom and the methyl group of the methylsulfinyl substituent lie on opposite sides of the plane of the benzofuran fragment. The 2-phenyl ring is rotated out of the benzofuran plane, making a dihedral angle of 32.1 (2)°. The crystal structure is stabilized by aromatic π–π interactions between the benzene rings of neighbouring molecules [centroid–centroid distance = 3.690 (5) Å]. In addition, the crystal structure exhibits intermolecular C—H⋯O and C—H⋯F interactions.

In the title compound, C 15 H 11 FO 2 S, the O atom and the methyl group of the methylsulfinyl substituent lie on opposite sides of the plane of the benzofuran fragment. The 2-phenyl ring is rotated out of the benzofuran plane, making a dihedral angle of 32.1 (2) . The crystal structure is stabilized by aromaticinteractions between the benzene rings of neighbouring molecules [centroid-centroid distance = 3.690 (5) Å ]. In addition, the crystal structure exhibits intermolecular C-HÁ Á ÁO and C-HÁ Á ÁF interactions.
The benzofuran unit is essentially planar, with a mean deviation of 0.011 (3) Å from the least-squares plane defined by the nine constituent atoms. The dihedral angle formed by the planes of the benzofuran and the phenyl rings is 3.690 (5)°.
The crystal packing ( Fig. 2) is stabilized by aromatic π-π interactions between the benzene rings of the adjacent molecules, with a Cg···Cg distance of 3.690 (5) Å (Cg is the centroid of the C2-C7 benzene ring). The crystal packing ( Fig. 2) exhibits four C-H···O and an C-H···F intermolecular interactions (Table 1 and Fig. 2).

Experimental
The 77% 3-chloroperoxybenzoic acid (291 mg, 1.3 mmol) was added in small portions to a stirred solution of 5-fluoro-3methylsulfanyl-2-phenyl-1-benzofuran (310 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 83%, m.p. 462-463 K; R f = 0.47 (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 tetrahydrofuran 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.
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.