5-Fluoro-2-(4-iodophenyl)-3-methylsulfinyl-1-benzofuran

In the title compound, C15H10FIO2S, the O atom and the methyl group of the methylsulfinyl substituent lie on opposite sides of the plane through the benzofuran fragment. The 4-iodophenyl ring is rotated out of the benzofuran plane by a dihedral angle of 39.4 (1)°. The crystal structure is stabilized by an intermolecular C—H⋯O hydrogen bond and an I⋯O halogen bond [3.055 (2) Å]. The crystal structure also exhibits an intermolecular C—H⋯π interaction between the methyl H atom and the 4-iodophenyl ring of an adjacent benzofuran molecule, and aromatic π–π interactions between the benzene rings of neighbouring benzofuran systems [centroid–centroid distance = 3.558 (3) Å].

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: VM2001).
The benzofuran unit is essentially planar, with a mean deviation of 0.010 (2) Å from the least-squares plane defined by the nine constituent atoms. The dihedral angle formed by the planes of the benzofuran and the 4-iodophenyl rings is 39.4 (1)°.
The crystal packing (Fig. 2) is stabilized by an intermolecular C-H···O hydrogen bond and an I···O halogen bond (Politzer et al., 2007); the first between the methyl H atom and the S═O unit, with a C15-H15C···O2 i distance of 3.238 (3) Å (Table   1), the second between the iodine atom and the oxygen of the S═O unit, i.e. an I···O distance of 3.055 (2) Å and a nearly linear C12-I···O2 iii angle of 165.26 (8)°. The crystal packing (Fig. 3) also exhibits an intermolecular C-H···π interaction between the methyl H atom and the 4-bromophenyl ring of an adjacent molecule, with a C15-H15B···Cg3 ii (Table 1; Cg3 is the centroid of the C9-C14 benzene ring). The further stability comes from aromatic π-π interaction between the furan and the benzene rings of the adjacent molecules, with a Cg1···Cg2 iv distance of 3.558 (3) Å ( Fig. 3; Cg1 and Cg2 are the centroids of the C1/C2/C7/O2/C8 furan ring and the C2-C7 benzene ring, respectively).

Experimental
The 77% 3-chloroperoxybenzoic acid (291 mg, 1.3 mmol) was added in small portions to a stirred solution of 5-fluoro-2-(4-iodophenyl)-3-methylsulfanyl-1-benzofuran (310 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 (hexan-ethyl acetate, 1 : 2 v/v) to afford the title compound as a colorless solid [yield 81%, m.p. 482-483 K; Single crystals suitable for X-ray diffraction were prepared by slow evaporation of a solution of the title compound in tetrahydrofuran at room temperature.

Refinement
All H atoms were positioned geometrically and refined using a riding model, with C-H = 0.93 Å for aromatic H atoms and 0.96 Å for methyl H atoms, respectively, and with U iso (H) = 1.2U eq (C) for aromatic H atoms and 1.5 U eq (C) for methyl H atoms, respectively.  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.