5-Chloro-3-cyclohexylsulfinyl-2-methyl-1-benzofuran

There are two independent molecules in the asymmetric unit of the title compound, C15H17ClO2S, in each of which the cyclohexyl rings adopt chair conformations. In the crystal, molecules are linked by weak intermolecular C—H⋯O hydrogen bonds.

There are two independent molecules in the asymmetric unit of the title compound, C 15 H 17 ClO 2 S, in each of which the cyclohexyl rings adopt chair conformations. In the crystal, molecules are linked by weak intermolecular C-HÁ Á ÁO hydrogen bonds.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: HG5004).

Comment
Many compounds containing a benzofuran ring exhibit interesting pharmacological properties such as antifungal, antitumor and antiviral, and antimicrobial 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 study of the substituent effect on the solid state structures of 3-cyclohexylsulfinyl-5-halo-2-methyl-1-benzofuran analogues (Choi et al., 2011), we report herein on the crystal structure of the title compound.
The title compound crystallizes as the non-centrosymmetric space group P2 1 in spite of having no asymmetric C atoms.
The asymmetric unit of the title compound is shown in Fig. 1. There are two independent unique molecules [ A & B] in which the benzofuran unit is essentially planar, with a mean deviation of 0.007 (1) Å for A and 0.009 (1) Å for B, respectively, from the least-squares plane defined by the nine constituent atoms. The cyclohexyl rings are in the chair form. The molecular packing is stabilized by weak intermolecular C-H···O hydrogen bonds between a benzene H atom and the O atom of the sulfinyl group (Table 1; C5-H5···O2 i ).

Experimental
77% 3-chloroperoxybenzoic acid (269 mg, 1.2 mmol) was added in small portions to a stirred solution of 5-chloro-3-cyclohexylsulfanyl-2-methyl-1-benzofuran (309 mg, 1.1 mmol) in dichloromethane (40 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. 382-383 K; R f = 0.47 (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 aectone at room temperature.

Refinement
All H atoms were positioned geometrically and refined using a riding model, with C-H = 0.95 Å for aryl, 1.00 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 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.