7-Bromo-2-(4-fluorophenyl)-1-(methylsulfinyl)naphtho[2,1-b]furan

In the title compound, C19H12BrFO2S, the O atom and the methyl group of the methylsulfinyl substituent lie on opposite sides of the plane through the naphthofuran fragment. The 4-fluorophenyl ring is rotated out of the naphthofuran plane, making a dihedral angle of 41.65 (7)°. In the crystal, molecules are linked by weak intermolecular C—H⋯O and C—H⋯π interactions, and a short Br⋯F contact [3.046 (2) Å] occurs. The O atom of the sulfinyl group is disordered over two positions, with refined site-occupancy factors of 0.912 (4) and 0.088 (4).

In the title compound, C 19 H 12 BrFO 2 S, the O atom and the methyl group of the methylsulfinyl substituent lie on opposite sides of the plane through the naphthofuran fragment. The 4fluorophenyl ring is rotated out of the naphthofuran plane, making a dihedral angle of 41.65 (7) . In the crystal, molecules are linked by weak intermolecular C-HÁ Á ÁO and C-HÁ Á Á interactions, and a short BrÁ Á ÁF contact [3.046 (2) Å ] occurs. The O atom of the sulfinyl group is disordered over two positions, with refined site-occupancy factors of 0.912 (4) and 0.088 (4).
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: ZL2274).
The naphthofuran unit is essentially planar, with a mean deviation of 0.040 (2) Å from the least-squares plane defined by the thirteen constituent atoms. The oxygen of the sulfinyl group is disordered over two positions with site-occupancy factors  Table 1 for numerical values and symmetry operators; Cg is the centroid of the atoms C2/C3/C8/C9/C10/C11 of the benzene ring). Furthermore, a short Br···F iv contact ( Fig. 2) [3.046 (2) Å] provides additional stabilization.
Experimental 77% 3-Chloroperoxybenzoic acid (202 mg, 0.9 mmol) was added in small portions to a stirred solution of 7-bromo-2-(4fluorophenyl)-1-(methylsulfanyl)naphtho[2,1-b]furan (310 mg, 0.8 mmol) in dichloromethane (30 mL) at 273 K. After being stirred at room temperature for 5h, 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, 1:1 v/v) to afford the title compound as a colorless solid [yield 76%, m.p. 501-502 K; R f = 0.66 (hexane-ethyl acetate, 1:1 v/v)]. Single crystals suitable for X-ray diffraction were prepared by slow evaporation of a solution of the title compound in chloroform at room temperature.

Refinement
All H atoms were geometrically positioned and refined using a riding model, with C-H = 0.95 Å for aryl and 0.98 Å for methyl H atoms. U iso (H) = 1.2U eq (C) for aryl and 1.5U eq (C) for methyl H atoms. The S═O distances (A & B) were restrained to be the same within a standard deviation of 0.002 Å using SADI command as defined in SHELXTL (Sheldrick, 2008 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. The bond towards the minor occupied oxygen atom is shown in a dashed mode.

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.