5-Fluoro-3-(4-fluorophenylsulfonyl)-2-methyl-1-benzofuran

In the title compound, C15H10F2O3S, the 4-fluorophenyl ring makes a dihedral angle of 73.20 (4)° with the plane of the benzofuran fragment. The crystal structure is stabilized by aromatic π–π interactions between the furan and benzene rings of neighbouring molecules [centroid–centroid distance = 3.805 (3) Å]. The crystal structure also exhibits weak intermolecular C—H⋯O and C—H⋯F interactions.

In the title compound, C 15 H 10 F 2 O 3 S, the 4-fluorophenyl ring makes a dihedral angle of 73.20 (4) with the plane of the benzofuran fragment. The crystal structure is stabilized by aromaticinteractions between the furan and benzene rings of neighbouring molecules [centroid-centroid distance = 3.805 (3) Å ]. The crystal structure also exhibits weak intermolecular C-HÁ Á ÁO and C-HÁ Á ÁF interactions.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: ZL2288).
The benzofuran unit is essentially planar, with a mean deviation of 0.013 (1) Å from the least-squares plane defined by the nine constituent atoms. The dihedral angle formed by the benzofuran plane and the 4-fluorophenyl ring is 73.20 (4)°. The crystal packing (Fig. 2) is stabilized by aromatic π-π interactions between the furan and the benzene rings of neighbouring molecules, with a Cg1···Cg2 iii distance of 3.805 (3) Å (Cg1 and Cg2 are the centroids of the C1/C2/C7/O1/C8 furan ring and the C2-C7 benzene ring, respectively). The molecular packing (Fig. 2) is further stabilized by a weak intermolecular C-H···O hydrogen bond between the 4-fluorophenyl H atom and the oxygen of the O═S═O unit (C11-H11···O2 i , see Table 1 for symmetry operator and numerical values). The crystal packing (Fig. 2) also exhibits C-H···F hydrogen bonds between the 4-fluorophenyl H atom and the fluorine of 4-fluorophenyl ring (C14-H14···F2 ii , Table 1).

Experimental
77% 3-chloroperoxybenzoic acid (381 mg, 1.7 mmol) was added in small portions to a stirred solution of 5-fluoro-3-(4fluorophenylsulfanyl)-2-methyl-1-benzofuran (221 mg, 0.8 mmol) in dichloromethane (40 mL) at 273 K. After being stirred at room temperature for 8h, 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 (benzene) to afford the title compound as a colorless solid [yield 76%, m.p. 426-427 K; R f = 0.49 (benzene)]. 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 = 0.93 Å for aryl and 0.96 Å for methyl H atoms. U iso (H) = 1.2U eq (C) for aryl 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.