5-Fluoro-2-methyl-3-(3-methylphenylsulfonyl)-1-benzofuran

In the title compound, C16H13FO3S, the dihedral angle between the mean planes of the benzofuran ring system and the 3-methylphenyl ring is 80.96 (4)°. In the crystal, molecules are linked via pairs of π–π interactions between furan and benzene rings, with centroid–centroid distances of 3.758 (1) and 3.771 (1) Å. A similar interaction is found between furan rings, with a centroid–centroid distance of 3.661 (1) Å between neighbouring molecules. The molecules stack along the a-axis direction. In addition, C—H⋯O and C—H⋯π hydrogen bonds are observed between inversion-related dimers.

In the title compound, C 16 H 13 FO 3 S, the dihedral angle between the mean planes of the benzofuran ring system and the 3-methylphenyl ring is 80.96 (4) . In the crystal, molecules are linked via pairs ofinteractions between furan and benzene rings, with centroid-centroid distances of 3.758 (1) and 3.771 (1) Å . A similar interaction is found between furan rings, with a centroid-centroid distance of 3.661 (1) Å between neighbouring molecules. The molecules stack along the a-axis direction. In addition, C-HÁ Á ÁO and C-HÁ Á Á hydrogen bonds are observed between inversion-related dimers.

Related literature
For background information and the crystal structures of related compounds, see: Choi et al. (2010aChoi et al. ( ,b, 2012 Table 1 Hydrogen-bond geometry (Å , ).
Supporting information for this paper is available from the IUCr electronic archives (Reference: BG2523).

Synthesis and crystallization
3-Chloroperoxybenzoic acid (77%, 448 mg, 2.0 mmol) was added in small portions to a stirred solution of 5-fluoro-2methyl-3-(3-methylphenylsulfanyl)-1-benzofuran (245 mg, 0.9 mmol) in dichloromethane (30 mL) at 273 K. After being stirred at room temperature for 8h, the mixture was washed with a 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. 375-376 K; R f = 0.51 (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 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 and 0.98 Å for methyl H atoms, respectively. U iso (H) = 1.2U eq (C) for aryl and 1.5U eq (C) for methyl H atoms. The positions of methyl hydrogens were optimized using the SHELXL-97's command AFIX 137 (Sheldrick, 2008).
In the title molecule ( Fig. 1), the benzofuran ring system is essentially planar, with a mean deviation of 0.006 (1) Å from the least-squares plane defined by the nine constituent atoms. The 3-methylphenyl ring is essentially planar, with a mean deviation of 0.003 (1) Å from the least-squares plane defined by the six constituent atoms. The dihedral angle formed by the benzofuran ring system and the 3-methylphenyl ring is 80.96 (4)°.
In the crystal structure ( Fig. 2), the molecules are linked via pairs of π···π interactions between the furan and benzene rings, and between the furan rings of neighbouring molecules. The molecules stack along the a-axis direction. The relevant centroid names for π···π stacking interactions are Cg1 for the furan ring (C1/C2/C7/O1/O8) and Cg2 for the benzene ring (C2-C7). The centroid-centroid separations of Cg1···Cg2 ii [(ii): -x + 1, -y + 1, -z + 1], Cg1···Cg2 iii and Cg1···Cg1 iii [(iii): -x + 2,-y + 1, -z + 1] are 3.758 (1), 3.771 (1) and 3.661 (1) Å, respectively. The slippages of Cg1···Cg2 ii , Cg1···Cg2 iii and Cg1···Cg1 iii are 1.227 (1), 1.266 (1) Å and 0.887 (1) Å, respectively. In the crystal packing ( Fig. 2), intermolecular C-H···O and C-H···π hydrogen bonds are observed between inversion-related dimers.  The molecular structure of the title molecule with the atom numbering scheme The displacement ellipsoids are drawn at the 50% probability level. The hydrogen atoms are presented as small spheres of arbitrary radius.   where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.26 e Å −3 Δρ min = −0.41 e Å −3 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.