5-Cyclohexyl-2-methyl-3-phenylsulfonyl-1-benzofuran

In the title compound, C21H22O3S, the cyclohexyl ring adopts a chair conformation. The phenyl ring makes a dihedral angle of 78.07 (5)° with the mean plane of the benzofuran fragment. In the crystal, molecules are linked through weak intermolecular C—H⋯O hydrogen bonds and C—H⋯π interactions.

In the title compound, C 21 H 22 O 3 S, the cyclohexyl ring adopts a chair conformation. The phenyl ring makes a dihedral angle of 78.07 (5) with the mean plane of the benzofuran fragment. In the crystal, molecules are linked through weak intermolecular C-HÁ Á ÁO hydrogen bonds and C-HÁ Á Á interactions.

Comment
Recently, compounds involving a benzofuran moiety have attracted much attention owing to their valuable pharmacological properties such as antibacterial, antifungal, antitumor, antiviral, and antimicrobial activities (Aslam et al., 2009, Galal et al., 2009, Khan et al., 2005. These compounds occur in a wide range of natural products (Akgul & Anil, 2003;Soekamto et al., 2003). As a part of our ongoing program of stydying substituent effect on solid state structures of analogues of 3-arylsulfonyl-5-cyclohexyl-2-methyl-1-benzofuran (Choi et al., 2011a,b ), we report herein crystal structure of the title compound.
In the title molecule ( Fig. 1), the benzofuran unit is essentially planar, with a mean deviation of 0.005 (1) Å from the least-squares plane defined by the nine constituent atoms. The cyclohexyl ring is in the chair form. The phenyl ring makes a dihedral angle of 78.07 (5)° with the mean plane of the benzofuran ring. The crystal packing (Fig. 2) is stabilized by weak intermolecular C-H···O hydrogen bonds between a phenyl H atom and the O atom of the sulfonyl group (Table; C21-H21···O3 i ). The crystal packing (Fig. 2) is further stabilized by intermolecular C-H···π interactions between a cyclohexyl H atom and the furan ring (Table 1; C11-H11B···Cg ii , Cg is the centroid of the C1/C2/C7/O1/C8 furan ring), Experimental 77% 3-chloroperoxybenzoic acid (493 mg, 2.2 mmol) was added in small portions to a stirred solution of 5-cyclohexyl-2methyl-3-phenylsulfanyl-1-benzofuran (354 mg, 1.1 mmol) in dichloromethane (40 mL) at 273 K. After being stirred at room temperature for 8h, 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, 4:1 v/v) to afford the title compound as a colorless solid [yield 71%, m.p. 430-431 K; R f = 0.48 (hexane-ethyl acetate, 4:1 v/v)]. Single crystals suitable for X-ray diffraction were prepared by slow evaporation of benzene solution of the title compound at room temperature.

Refinement
All H atoms were placed geometrically and refined using a riding model, with C-H = 0.95 Å for aryl, 1.00 Å for methine, 0.99 Å for methylene and 0.98 Å for methyl H atoms, respectively. U iso (H) = 1.2U eq (C) for aryl, methine, methylene, and 1.5U eq (C) for methyl H atoms. Positions of H atoms of the methyl group were optimized rotationally using AFIX 137 instruction.
supplementary materials sup-2 Figures Fig. 1. The molecular structure of the title compound with atom numbering scheme. Displacement ellipsoids are drawn at 50% probability level. H atoms are represented 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.
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.