5-Bromo-2-(4-fluorophenyl)-3-phenylsulfinyl-1-benzofuran

In the title compound, C20H12BrFO2S, the 4-fluorophenyl ring makes a dihedral angle of 2.63 (6)° with the mean plane of the benzofuran fragment. The dihedral angle between the phenyl ring and the mean plane of the benzofuran fragment is 84.60 (6)°. In the crystal, molecules are linked by weak intermolecular C—H⋯O hydrogen bonds, and slipped π–π interactions between the benzene rings of neighbouring molecules [centroid–centroid distance = 3.719 (3) Å, interplanar distance = 3.000 (3) Å and slippage = 1.520 (3) Å].

In the title compound, C 20 H 12 BrFO 2 S, the 4-fluorophenyl ring makes a dihedral angle of 2.63 (6) with the mean plane of the benzofuran fragment. The dihedral angle between the phenyl ring and the mean plane of the benzofuran fragment is 84.60 (6) . In the crystal, molecules are linked by weak intermolecular C-HÁ Á ÁO hydrogen bonds, and slippedinteractions between the benzene rings of neighbouring molecules [centroid-centroid distance = 3.719 (3) Å , interplanar distance = 3.000 (3) Å and slippage = 1.520 (3) Å ].
of 5-halo-2-(4-halophenyl)-3-phenylsulfinyl-1-benzofuran analogues (Choi et al., 2010(Choi et al., , 2011, we report herein the crystal structure of the title compound. In the title molecule ( Fig. 1), the benzofuran unit is essentially planar, with a mean deviation of 0.008 (2) Å from the least-squares plane defined by the nine constituent atoms. The dihedral angle formed by the 4-fluorophenyl ring and the mean plane of the benzofuran fragment is 2.63 (6)°, and the dihedral angle between the phenyl ring and the mean plane of the benzofuran fragment is 84.60 (6)°. The crystal packing (Fig. 2) is stabilized by weak intermolecular C-H···O hydrogen bonds; the first one between a 4-fluorophenyl H atom and the O atom of the sulfinyl group (Table 1; C13-H13···O2 i ), and the second one between a phenyl H atom and the O atom of the sulfinyl group (Table 1; C19-H19···O2 ii ). The crystal packing ( Fig. 2) is further stabilized by weak slipped π-π interactions between the benzene rings of adjacent molecules, with Cg···Cg iii distance of 3.719 (3) Å and an interplanar distance of 3.000 (3) Å resulting in a slippage of 1.520 (3) Å (Cg is the centroids of the C2-C7 benzene ring).

Experimental
77% 3-chloroperoxybenzoic acid (202 mg, 0.9 mmol) was added in small portions to a stirred solution of 5-bromo-2-(4fluorophenyl)-3-phenylsulfanyl-1-benzofuran (319 mg, 0.8 mmol) in dichloromethane (30 mL) at 273 K. After being stirred at room temperature for 4h, the mixture was washed with saturated sodium bicarbonate solution and the organic layer was separated, dried over magnesium sulfate, filtered and concentrated at reduced pressure. The residue was purified by column chromatography (hexane-ethyl acetate, 2:1 v/v) to afford the title compound as a colorless solid [yield 67%, m.p. 473-474 K; Rf = 0.70 (hexane-ethyl acetate, 2:1 v/v)]. Single crystals suitable for X-ray diffraction were prepared by slow evaporation of a solution of the title compound in benzene at room temperature.

Refinement
All H atoms were positioned geometrically and refined using a riding model, with C-H = 0.95 Å for aryl H atoms. U iso (H) = 1.2U eq (C) for aryl H atoms.
supplementary materials sup-2 Figures Fig. 1. The molecular structure of the title compound with the atom numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are presented as small spheres of arbitrary radius.

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.