5-Cyclohexyl-3-(4-fluorophenylsulfonyl)-2-methyl-1-benzofuran

In the title compound, C21H21FO3S, the cyclohexyl ring adopts a chair conformation. The 4-fluorophenyl ring makes a dihedral angle of 77.71 (4)° with the mean plane of the benzofuran fragment. In the crystal, molecules are linked through intermolecular C—H⋯O hydrogen bonds and aromatic π–π interactions between the furan rings of neighbouring molecules [centroid–centroid distance = 3.578 (2) Å].

In the title compound, C 21 H 21 FO 3 S, the cyclohexyl ring adopts a chair conformation. The 4-fluorophenyl ring makes a dihedral angle of 77.71 (4) with the mean plane of the benzofuran fragment. In the crystal, molecules are linked through intermolecular C-HÁ Á ÁO hydrogen bonds and aromaticinteractions between the furan rings of neighbouring molecules [centroid-centroid distance = 3.578 (2) Å ].
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: KP2311). 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 a part of our ongoing program of the substituent effect on the solid state structures of 3-(4-fluorophenylsulfonyl)-2-methyl-1-benzofuran analogues (Choiet al., 2010a,b), we report herein on the crystal structure of the title compound.

5-Cyclohexyl
In the title molecule ( Fig. 1), the benzofuran unit is essentially planar, with a mean deviation of 0.013 (1) Å from the leastsquares plane defined by the nine constituent atoms. The cyclohexyl ring is in the chair conformation. The 4-fluorophenyl ring makes a dihedral angle of 77.71 (4)° with the mean plane of the benzofuran ring. The crystal packing (Fig. 2, Table 1) is stabilised by intermolecular C-H···O hydrogen bonds; the first one between a 4-fluorophenyl H atom and the oxygen of the O═S═O unit (Table 1; C17-H17···O3 i ), the second one between a 4-fluorophenyl H atom and the furan O atom (Table 1; C20-H20···O1 i ), the third one between a 4-fluorophenyl H atom and the oxygen of the O═S═O unit (Table 1; C21-H21···O2 iii ). The crystal packing (Fig. 3) is also stabilised by an aromatic π-π interaction between the furan rings of adjacent molecules, with a Cg···Cg i distance of 3.578 (2) Å (Cg is the centroid of the C1/C2/C7/O1/C8 furan ring).
Experimental 3-Chloroperoxybenzoic acid, 77% (426 mg, 1.9 mmol) was added in small portions to a stirred solution of 5-cyclohexyl-3-(4-fluorophenylsulfanyl)-2-methyl-1-benzofuran (306 mg, 0.9 mmol) in dichloromethane (40 mL) at 273 K. After being stirred at room temperature for 6 h, 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 colourless solid [yield 73%, m.p. 426-427 K; R f = 0.68 (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 benzene at room temperature.

Refinement
All H atoms were positioned geometrically and refined using a riding model, with C-H = 0.93 Å for aryl, 0.98 Å for methine, 0.97 Å for methylene and 0.96 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.