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

In the title compound, C15H10ClFO2S, the O atom and the methyl group of the methylsulfinyl substituent are located on opposite sides of the plane through the benzofuran fragment. The 4-fluorophenyl ring is rotated out of the benzofuran plane, making a dihedral angle of 25.99 (4)°. The crystal structure is stabilized by a non-classical intermolecular C—H⋯O hydrogen bond and a Cl⋯O halogen bond [3.244 (1) Å].

In the title compound, C 15 H 10 ClFO 2 S, the O atom and the methyl group of the methylsulfinyl substituent are located on opposite sides of the plane through the benzofuran fragment. The 4-fluorophenyl ring is rotated out of the benzofuran plane, making a dihedral angle of 25.99 (4) . The crystal structure is stabilized by a non-classical intermolecular C-HÁ Á ÁO hydrogen bond and a ClÁ Á ÁO halogen bond [3.244 (1) Å ].
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: ZQ2011).

Comment
Molecules involving benzofuran moiety have received considerable attention owing to a variety of their biological activities (Howlett et al., 1999;Twyman & Allsop, 1999) and these compounds are ubiquitous in nature (Akgul & Anil, 2003;Soekamto et al., 2003). As a part of our continuing studies of the effect of side chain substituents on the solid state structures of 2-(4-halophenyl)-3-methylsulfinyl-1-benzofuran analogues (Choi et al., 2009a,b), we report the crystal structure of the title compound (Fig. 1).
The benzofuran unit is essentially planar, with a mean deviation of 0.008 (1) Å from the least-squares plane defined by the nine constituent atoms. The dihedral angle formed by the plane of the benzofuran ring and the 4-fluorophenyl ring is 25.99 (4)°. The crystal packing ( Fig. 2) is stabilized by a non-classical intermolecular C-H···O hydrogen bond between the 4-fluorophenyl H atom and the oxygen of the S═O unit, with a C14-H14···O2 i (Table 1), and a Cl···O halogen bond between the chlorine and the oxygen of the S═O unit [Cl···O2 ii = 3.244 (1) Å; C-Cl···O = 174.59 (5) °] (Politzer et al., 2007).

Experimental
77% 3-Chloroperoxybenzoic acid (291 mg, 1.3 mmol) was added in small portions to a stirred solution of 5-chloro-2-(4fluorophenyl)-3-methylsulfanyl-1-benzofuran (370 mg, 1.2 mmol) in dichloromethane (30 mL) at 273 K. After being stirred at room temperature for 3h, the mixture was washed with saturated sodium bicarbonate solution and the organic layer was separated, dried over magnesium sulfate, filtered and concentrated in vacuum. The residue was purified by column chromatography (hexane-ethyl acetate, 1:1 v/v) to afford the title compound as a colorless solid [yield 86%, m.p. 492-493 K; R f = 0.64 (hexane-ethyl acetate, 1:1 v/v)]. Single crystals suitable for X-ray diffraction were prepared by slow evaporation of a solution of the title compound in chloroforrm at room temperature.

Refinement
All H atoms were positioned geometrically and refined using a riding model, with C-H = 0.95 Å for aromatic H atoms and 0.98 Å for methyl H atoms, and with U iso (H) = 1.2U eq (C) for aromatic H atoms and 1.5U eq (C) for methyl H atoms. 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.