5-Bromo-3-cyclohexylsulfinyl-2,4,6-trimethyl-1-benzofuran

In the title compound, C17H21BrO2S, the cyclohexyl ring adopts a chair conformation and the arylsulfinyl unit is positioned equatorially relative to the cyclohexyl group. The benzofuran unit is essentially planar, with an r.m.s. deviation of 0.016 (2) Å. In the crystal, molecules are linked by weak C—H⋯O, C—H⋯π and Br⋯π [3.663 (2) Å] interactions, resulting in a three-dimensional network. A Br⋯Br [3.6838 (6) Å] contact is observed. The O atom of the sulfinyl group is disordered over two orientations with an occupancy ratio of 0.863 (5):0.137 (5).

In the title compound, C 17 H 21 BrO 2 S, the cyclohexyl ring adopts a chair conformation and the arylsulfinyl unit is positioned equatorially relative to the cyclohexyl group. The benzofuran unit is essentially planar, with an r.m.s. deviation of 0.016 (2) Å . In the crystal, molecules are linked by weak C-HÁ Á ÁO, C-HÁ Á Á and BrÁ Á Á [3.663 (2) Å ] interactions, resulting in a three-dimensional network. A BrÁ Á ÁBr [3.6838 (6) Å ] contact is observed. The O atom of the sulfinyl group is disordered over two orientations with an occupancy ratio of 0.863 (5):0.137 (5).

Related literature
For background information and the crystal structures of related compounds, see: Choi et al. (2011a,b Table 1 Hydrogen-bond geometry (Å , ).

Comment
As a part of our ongoing study of 5-bromo-3-cyclohexylsulfinyl-1-benzofuran derivatives containing a methyl group in 2position (Choi et al. , 2011a) and methyl substituents in the 2,7-positions (Choi et al. , 2011b), 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 0.016 (2) Å from the least-squares plane defined by the nine constituent atoms. The cyclohexyl ring is in the chair form and the arylsulfinyl moiety is positioned equatorial relative to the cyclohexyl group. The O atom of the sulfinyl group is disordered over two positions with site-occupancy factors, from refinement, of 0.863 (5) (part A) and 0.137 (5) (part B). In the crystal structure ( Fig. 2), molecules are connected by weak C-H···O and C-H···π hydrogen bonds (Table 1; Cg1 is the centroid of the C2-C7 benzene ring), and by C4-Br1···π interactions between the bromine atom and the furan ring of a neighbouring molecule with a Br1···Cg2 i = 3.663 (2) Å (Cg2 is the centroid of the C1/C2/C7/O1/C8 furan ring). The crystal packing (Fig. 2) also exhibits a Br1···Br1 iii contact at 3.6838 (6) Å.

Experimental
3-Chloroperoxybenzoic acid (77%, 224 mg, 1.0 mmol) was added in small portions to a stirred solution of 5-bromo-3cyclohexylsulfanyl-2,4,6-trimethyl-1-benzofuran (282 mg, 0.9 mmol) in dichloromethane (30 mL) at 273 K. After being stirred at room temperature for 6h, 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 71%, m.p. 450-451 K; R f = 0.46 (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 acetone at room temperature.

Refinement
All H atoms were positioned geometrically and refined using a riding model, with C-H = 0.95 Å for aryl, 1.0 Å for methine, 0.99 Å for methylene and 0.98 Å for methyl H atoms, respectively. U iso = 1.2U eq (C) for aryl, methine and methylene, and 1.5U eq for methyl H atoms. The positions of methyl hydrogens were optimized rotationally. The O atom of sulfinyl group is disordered over two positions with site-ccupancy factors, from refinement of 0.863 (5) (part A) and 0.137 (5) (part B). The distance of S-O sets was restrained to 0.001 Å using command SADI and DELU.   where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.001 Δρ max = 1.28 e Å −3 Δρ min = −0.88 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.