5-Bromo-2,4,6-trimethyl-3-(4-methylphenylsulfinyl)-1-benzofuran

In the title compound, C18H17BrO2S, the dihedral angle between the methylphenyl ring and the mean plane of the benzofuran rung system is 87.0 (2)°. In the crystal, molecules related by inversion are paired into dimers via C—H⋯O and C—H⋯π interactions. These dimers are further linked by C—H⋯O hydrogen bonds and π–π interactions between the benzene and furan rings of neighbouring molecules [centroid–centroid distance = 3.555 (5) Å], resulting in a three-dimensional supramolecular network.

In the title compound, C 18 H 17 BrO 2 S, the dihedral angle between the methylphenyl ring and the mean plane of the benzofuran rung system is 87.0 (2) . In the crystal, molecules related by inversion are paired into dimers via C-HÁ Á ÁO and C-HÁ Á Á interactions. These dimers are further linked by C-HÁ Á ÁO hydrogen bonds andinteractions between the benzene and furan rings of neighbouring molecules [centroidcentroid distance = 3.555 (5) Å ], resulting in a three-dimensional supramolecular network.

Related literature
For background information and the crystal structures of related compounds, see: Choi et al. (2008Choi et al. ( , 2011 Table 1 Hydrogen-bond geometry (Å , ).
Supporting information for this paper is available from the IUCr electronic archives (Reference: XU5773).
In the title molecule ( Fig. 1), the benzofuran unit is essentially planar, with a mean deviation of 0.017 (3) Å from the least-squares plane defined by the nine constituent atoms. The 4-methylphenyl ring is essentially planar, with a mean deviation of 0.007 (4) Å from the least-squares plane defined by the six constituent atoms. The dihedral angle formed by the benzofuran ring system and the 4-methylphenyl ring is 87.0 (2)°. In the crystal structure, Fig. 2, the molecules related by inversion are paired into dimers via C-H···O and C-H···π interactions (Table 1, Cg2 is the centroid of the C1/C2/C7/O1/C8 furan ring). These dimers are further packed by intermolecular C-H···O hydrogen bonds (Table 1) and π···π interactions between the benzene and furan rings of neighbouring molecules, with a Cg1···Cg2 iii distance of 3.555 (5) Å and an interplanar distance of 3.499 (5) Å resulting in a slippage of 0.629 (5) Å (Cg1 is the centroid of the C2-C7 benzene ring), resulting in a three-dimensional network.

Experimental
3-Chloroperoxybenzoic acid (77%, 224 mg, 1.0 mmol) was added in small portions to a stirred solution of 5bromo-2,4,6-trimethyl-3-(4-methylphenylsulfanyl)-1-benzofuran (325 mg, 0.9 mmol) in dichloromethane (30 mL) at 273 K. After being stirred at room temperature for 5h, 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 69%, m.p. 470-471 K; R f = 0.51 (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 and 0.98 Å for methyl H atoms. 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. The highest peak in the difference map is 0.88 Å from BR1 and the deepest hole is 0.95 Å from    where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.001 Δρ max = 1.44 e Å −3 Δρ min = −1.27 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.