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

In the title compound, C15H10BrFO3S, the 4-fluorophenyl ring makes a dihedral angle of 76.51 (6)° with the plane of the benzofuran fragment. In the crystal, molecules are linked by weak non-classical intermolecular C—H⋯O hydrogen bonds and an aromatic π–π interaction between the benzene rings of neighbouring molecules [centroid–centroid distance = 3.540 (3) Å].

In the title compound, C 15 H 10 BrFO 3 S, the 4-fluorophenyl ring makes a dihedral angle of 76.51 (6) with the plane of the benzofuran fragment. In the crystal, molecules are linked by weak non-classical intermolecular C-HÁ Á ÁO hydrogen bonds and an aromaticinteraction between the benzene rings of neighbouring molecules [centroid-centroid distance = 3.540 (3) Å ].
The benzofuran unit is essentially planar, with a mean deviation of 0.013 (2)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 76.51 (6)°.
The molecular packing (Fig. 2) is stabilized by a weak intermolecular non-classical C-H···O hydrogen bond between the 4-fluorophenyl H atom and the oxygen of the O═S═O unit, with a C15-H15···O3 i ( Table 1). The crystal packing ( Fig. 2) is further stabilized by an aromatic π-π interaction between the benzene rings of neighbouring molecules, with a Cg···Cg ii distance of 3.540 (3)Å (Cg is the centroid of the C2-C7 benzene ring).

Experimental
The 77% 3-chloroperoxybenzoic acid (493 mg, 2.2 mmol) was added in small portions to a stirred solution of 5-bromo-3-(4-fluorophenylsulfanyl)-2-methyl-1-benzofuran (337 mg, 1.0 mmol) in dichloromethane (40 mL) at 273 K. After being stirred at room temperature for 10 h, 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 acetate, 2:1 v/v) to afford the title compound as a colourless solid [yield 74%, m.p. 459-460 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 acetone at room temperature.

Refinement
All H atoms were positioned geometrically and refined using a riding model, with C-H = 0.95Å for aryl and 0.98Å for methyl H atoms. The U iso (H) = 1.2U eq (C) for aryl H atoms and U iso (H) = 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. 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 > 2σ(F 2 ) is used only for calculating Rfactors(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.