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

In the title compound, C20H12ClFO2S, the O atom and the phenyl ring of the phenylsulfinyl substituent lie on opposite sides of the plane of the benzofuran fragment; the phenyl ring is almost perpendicular to this plane [82.44 (5)°]. The 4-fluorophenyl ring is rotated out of the benzofuran plane, making a dihedral angle of 20.83 (6)°.

In the title compound, C 20 H 12 ClFO 2 S, the O atom and the phenyl ring of the phenylsulfinyl substituent lie on opposite sides of the plane of the benzofuran fragment; the phenyl ring is almost perpendicular to this plane [82.44 (5) ]. The 4fluorophenyl ring is rotated out of the benzofuran plane, making a dihedral angle of 20.83 (6) .
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: RN2082).

Comment
Many compounds having a benzofuran ring system have attracted much attention owing to their pharmacological 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 part of our ongoing program of the substituent effect on the solid state structures of 5-halo-2-phenyl-3-phenylsulfinyl-1-benzofuran analogues (Choi et al., 2009a,b,c), we report herein on the crystal structure of the title compound.
In the title molecule ( Fig. 1), the benzofuran unit is essentially planar, with a mean deviation of 0.011 (1) Å from the least-squares plane defined by the nine constituent atoms. The phenyl ring makes a dihedral angle of 82.44 (5)° with the mean plane of the benzofuran fragment. The dihedral angle formed by the mean plane of the benzofuran fragment and the 4-fluorophenyl ring is 20.83 (6)°.
Experimental 77% 3-chloroperoxybenzoic acid (179 mg, 0.8 mmol) was added in small portions to a stirred solution of 5-chloro-2-(4fluorophenyl)-3-phenylsulfanyl-1-benzofuran (284 mg, 0.8 mmol) in dichloromethane (30 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 ace tate, 2:1 v/v) to afford the title compound as a colorless solid [yield 76%, m.p. 480-481 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 = 0.95 Å for aryl H atoms. U iso (H) = 1.2U eq (C) for aryl H atoms. 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.