5-Ethyl-3-(3-fluorophenylsulfonyl)-2-methyl-1-benzofuran

In the title compound, C17H15FO3S, the fluorophenyl ring makes a dihedral angle of 76.11 (5)° with the mean plane of the benzofuran fragment. In the crystal, molecules are linked by weak intermolecular C—H⋯O hydrogen bonds and C—H⋯π interactions.

In the title compound, C 17 H 15 FO 3 S, the fluorophenyl ring makes a dihedral angle of 76.11 (5) with the mean plane of the benzofuran fragment. In the crystal, molecules are linked by weak intermolecular C-HÁ Á ÁO hydrogen bonds and C-HÁ Á Á interactions.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: BH2350).

Comment
Many compounds having a benzofuran skeleton exhibit interesting biological properties such as antibacterial and antifungal, antitumor and 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 study of the substituent effect on the solid state structures of 5-alkyl-3-(4-fluorophenylsulfonyl)-2-methyl-1-benzofuran analogues (Choi et al., 2010a,b,c), we report herein on the molecular and crystal structures of the title compound.
The title compound crystallizes in the non-centrosymmetric space group P2 1 2 1 2 1 in spite of having no asymmetric C atoms.
In the title compound ( 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 3-fluorophenyl ring makes a dihedral angle of 76.11 (5)°w ith the mean plane of the benzofuran fragment. The crystal packing (Fig. 2) is stabilized by weak intermolecular C-H···O hydrogen bonds; the first one between a benzene H atom and the O atom of the sulfonyl group (Table 1; C6-H6···O2 i ), and the second one between a 3-fluorophenyl H atom and the O atom of the sulfonyl (Table 1; C13-H13···O3 ii ). The crystal packing ( Fig. 3) is further stabilized by intermolecular C-H···π interactions between a methylene H atom of the ethyl group and the benzene ring (Table 1; C9-H9A···Cg iii , Cg is the centroid of the C2···C7 benzene ring).

Experimental
77% 3-Chloroperoxybenzoic acid (560 mg, 2.5 mmol) was added in small portions to a stirred solution of 5-ethyl-3-(3fluorophenylsulfanyl)-2-methyl-1-benzofuran (320 mg, 1.2 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 colorless solid [yield 71%, m.p. 395-396 K; Single crystals suitable for X-ray diffraction were prepared by slow evaporation of a solution of the title compound in diisopropyl ether at room temperature.

Refinement
All H atoms were positioned geometrically and refined using a riding model, with C-H = 0.95 Å for aryl, 0.99 Å for methylene and 0.98 Å for methyl H atoms, respectively. U iso (H) = 1.2U eq (C) for aryl and methylene H atoms, and 1.5U eq (C) for methyl H atoms.
supplementary materials sup-2 Figures   Fig. 1. The molecular structure of the title compound with displacement ellipsoids drawn at the 50% probability level. H atoms are presented as a small spheres of arbitrary radius.