5-Bromo-3-ethylsulfinyl-2-(4-fluorophenyl)-7-methyl-1-benzofuran

In the title compound, C17H14BrFO2S, the 4-fluorophenyl ring is rotated slightly out of the benzofuran plane, making a dihedral angle of 7.60 (4)°. The crystal structure is stabilized by a Br⋯O halogen-bonding interaction [3.048 (1) Å].

In the title compound, C 17 H 14 BrFO 2 S, the 4-fluorophenyl ring is rotated slightly out of the benzofuran plane, making a dihedral angle of 7.60 (4) . The crystal structure is stabilized by a BrÁ Á ÁO halogen-bonding interaction [3.048 (1) Å ].

Experimental
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: NG2754).
The benzofuran unit is essentially planar, with a mean deviation of 0.013 (1) Å from the least-squares plane defined by the nine constituent atoms. The dihedral angle formed by the benzofuran plane and the 4-fluorophenyl ring is 7.60 (4)°.
Experimental 77% 3-Chloroperoxybenzoic acid (224 mg, 1.0 mmol) was added in small portions to a stirred solution of 5-bromo-3-ethylsulfanyl-2-(4-fluorophenyl)-7-methyl-1-benzofuran (329 mg, 0.9 mmol) in dichloromethane (40 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, 1:1 v/v) to afford the title compound as a colorless solid [yield 81%, m.p. 436-437 K; R f = 0.65 (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.

Refinement
All H atoms were positioned geometrically and refined using a riding model, with C-H = 0.95 Å for aryl, 0.98 Å for methylene and methyl H atoms. U iso (H)=1.2U eq (C) for aryl and methylene H atoms, and 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.  (17)