3-(2-Bromophenylsulfinyl)-2,5,7-trimethyl-1-benzofuran

In the title compound, C17H15BrO2S, both the benzofuran and 2-bromophenyl rings are virtually planar, with r.m.s. deviations of 0.009 (2) and 0.006 (2) Å, respectively. The dihedral angle between these mean planes is 89.31 (7)°. In the crystal, molecules are linked via pairs of C—H⋯π interactions into inversion dimers. These dimers are further linked by C—H⋯π interactions into supramolecular chains running along the b axis. In addition, C—S⋯π interactions, with an S-to-ring-centroid distance of 3.50 (2) Å, are observed between inversion-related dimers.

In the title compound, C 17 H 15 BrO 2 S, both the benzofuran and 2-bromophenyl rings are virtually planar, with r.m.s. deviations of 0.009 (2) and 0.006 (2) Å , respectively. The dihedral angle between these mean planes is 89.31 (7) . In the crystal, molecules are linked via pairs of C-HÁ Á Á interactions into inversion dimers. These dimers are further linked by C-HÁ Á Á interactions into supramolecular chains running along the b axis. In addition, C-SÁ Á Á interactions, with an S-toring-centroid distance of 3.50 (2) Å , are observed between inversion-related dimers.

Related literature
For background information and the crystal structures of related compounds, see: Choi et al. (2010Choi et al. ( , 2012 Table 1 Hydrogen-bond geometry (Å , ).
Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012) and DIAMOND (Brandenburg, 1998); software used to prepare material for publication: SHELXL97. In the title molecule ( Fig. 1), the benzofuran unit is essentially planar, with a mean deviation of 0.009 (2) Å from the least-squares plane defined by the nine constituent atoms. The 2-bromophenyl ring is essentially planar, with a mean deviation of 0.006 (2) Å from the least-squares plane defined by the six constituent atoms. The dihedral angle formed by the mean plane of the benzofuran ring system and the mean plane of the 2-bromophenyl ring is 89.31 (7)°. In the crystal packing ( Fig. 2), molecules are linked via pairs of C-H···π interactions (Table 1, Cg1 is the centroid of the C2-C7 benzene ring) into inversion dimers. These dimers are further linked by C-H···π interactions (Table 1, Cg2 is the centroid of C1/C2/C7/O1/C8 furan ring) into supramolecular chains running along the b-axis direction. In addition, there are weak intermolecular S···π interactions between the sulfur atom and the centroid of the 2-bromophenyl ring (C12-C17) of an adjacent molecule, with a S1···Cg3 iii being 3.508 (2) Å, resulting in inversion-related dimers.

Experimental
3-Chloroperoxybenzoic acid (77%, 224 mg, 1.0 mmol) was added in small portions to a stirred solution of 3-(2-bromophenylsulfanyl)-2,5,7-trimethyl-1-benzofuran (312 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, 2:1 v/v) to afford the title compound as a colorless solid [yield 68%, m.p. 457-458 K; R f = 0.53 (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 ethyl acetate at room temperature.

Refinement
All H atoms were positioned geometrically and refined using a riding model, with C-H = 0.95 Å for aryl, 0.99 Å for methyl H atoms, respectively. U iso (H) = 1.2U eq (C) for aryl and 1.5U eq (C) for methyl H atoms. The positions of methyl hydrogens were optimized rotationally.   (iii) -x + 1, -y + 1, -z; (iv) x, y -1, z.] where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.001 Δρ max = 0.29 e Å −3 Δρ min = −0.54 e Å −3 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.