5-Cyclohexyl-2-(4-fluorophenyl)-3-methylsulfinyl-1-benzofuran

In the title compound, C21H21FO2S, the cyclohexyl ring adopts a classic chair conformation. The 4-fluorophenyl ring makes a dihedral angle of 31.05 (6)° with the mean plane of the benzofuran fragment. In the crystal, molecules are linked through weak intermolecular C—H⋯O and C—H⋯π interactions.

In the title compound, C 21 H 21 FO 2 S, the cyclohexyl ring adopts a classic chair conformation. The 4-fluorophenyl ring makes a dihedral angle of 31.05 (6) with the mean plane of the benzofuran fragment. In the crystal, molecules are linked through weak intermolecular C-HÁ Á ÁO and C-HÁ Á Á interactions.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: FL2333).

Comment
Many compounds involving a benzofuran ring system have aroused much attention owing to their pharmacological properties such as antifungal, antimicrobial, antitumor and antiviral activities (Aslam et al., 2006;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 part of our ongoing program of the substituent effect on the solid state structures of 2-(4-fluorophenyl)-3-methylsulfinyl-1-benzofuran analogues (Choi et al., 2009(Choi et al., , 2010a, we report herein on the crystal structure of the title compound.
In the title molecule ( Fig. 1), the benzofuran unit is essentially planar, with a mean deviation of 0.017 (1) Å from the least-squares plane defined by the nine constituent atoms. The cyclohexyl ring is in the chair form. The 4-fluorophenyl ring makes a dihedral angle of 31.05 (6)° with the mean plane of the benzofuran ring. The crystal packing (Fig. 2) is stabilized by a weak intermolecular C-H···O interaction between a methyl H atom and the oxygen of the S═O unit (Table   1; C21-H21B···O2 i ). The crystal packing (Fig. 2) is further stabilized by intermolecular C-H···π interactions; the first one between a 4-fluorophenyl H atom and the furan ring (Table 1; C13-H13···Cg1 i , Cg1 is the centroid of the C1/C2/C7/O1/C8 furan ring), and the second one between a cyclohexyl H atom and the 4-fluorophenyl ring (Table 1; Cg2 is the centriod of the C9-C14 4-fluorophenyl ring).

Experimental
77% 3-chloroperoxybenzoic acid (202 mg, 0.9 mmol) was added in small portions to a stirred solution of 5-cyclohexyl-2-(4-fluorophenyl)-3-methylsulfanyl-1-benzofuran (306 mg, 0.9 mmol) in dichloromethane (30 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 76%, m.p. 464-465 K; R f = 0.54 (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 and 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 and methylene, and 1.5U eq (C) for methyl H atoms.
supplementary materials sup-2 Figures Fig. 1. The molecular structure of the title compound with the atom numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are presented as a 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.