3-Cyclohexylsulfonyl-5-isopropyl-2-methyl-1-benzofuran

In the title compound, C18H24O3S, the cyclohexyl ring adopts a chair conformation. In the crystal, molecules are linked through weak non-classical intermolecular C—H⋯O hydrogen bonds and C—H⋯π interactions.

In the title compound, C 18 H 24 O 3 S, the cyclohexyl ring adopts a chair conformation. In the crystal, molecules are linked through weak non-classical intermolecular C-HÁ Á ÁO hydrogen bonds and C-HÁ Á Á interactions.

D-HÁ
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: RK2267).

Comment
Many compounds having a benzofuran skeleton exhibit diverse 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-arylsulfonyl-5-isopropyl-2-methyl-1-benzofuran analogues (Choi et al., 2008(Choi et al., , 2010, we report herein the molecular and crystal structures of the title compound. In the title molecule ( Fig. 1), the benzofuran unit is essentially planar, with a mean deviation of 0.009 (1) Å from the least-squares plane defined by the nine constituent atoms. The cyclohexyl ring is in the chair form. The molecular packing ( Fig. 2) is stabilized by weak non-classical intermolecular C-H···O hydrogen bonds; the first one between a cyclohexyl H atom and the oxygen of the O═S═O unit (Table 1; C13-H13···O2 i ), the second one between a cyclohexyl H atom and the oxygen of the O═S═O unit (Table 1; C14-H14A···O3 ii ). The crystal packing (Fig. 2) is further stabilized by intermolecular C-H···π interactions between a methyl H atom of the isopropyl group and the benzene ring.

Experimental
The 3-chloroperoxybenzoic acid (77%, 560 mg, 2.5 mmol) was added in small portions to a stirred solution of 3-cyclohexylsulfanyl-5-isopropyl-2-methyl-1-benzofuran (346 mg, 1.2 mmol) in dichloromethane (40 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, 4:1 v/v) to afford the title compound as a colourless solid [yield 78%, m.p. 467-468 K; R f = 0.66 (hexane-ethyl acetate, 4:1 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 = 0.95Å for aryl, 1.00Å for methine, 0.99Å for methylene and 0.98Å 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.  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 > 2σ(F 2 ) is used only for calculating Rfactors(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.