1-(4-Bromophenylsulfinyl)-2-methylnaphtho[2,1-b]furan

In the title compound, C19H13BrO2S, the 4-bromophenyl ring makes a dihedral angle of 83.75 (4)° with the mean plane of the naphthofuran fragment [r.m.s. deviation = 0.024 (2) Å]. In the crystal, molecules are linked via pairs of C—H⋯O hydrogen bonds, forming inversion dimers. These dimers are connected by weak π–π interactions between the central naphthofuran benzene rings of neighbouring molecules [centroid–centroid distance = 3.483 (2) Å, interplanar distance = 3.416 (2) Å and slippage = 0.680 (2) Å].


Related literature
For background information and the crystal structures of related compounds, see: Choi et al. (2007Choi et al. ( , 2012 Table 1 Hydrogen-bond geometry (Å , ).
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: SJ5222).
In the title molecule ( Fig. 1), the naphthofuran unit is essentially planar, with a mean deviation of 0.024 (2) Å from the least-squares plane defined by the thirteen constituent atoms. The dihedral angle between the 4-bromophenyl ring and the mean plane of the naphthofuran fragment is 83.75 (4)°. In the crystal structure, molecules are linked via pairs of C-H···O hydrogen bonds ( Fig. 2 & Table 1), forming inversion dimers. These dimers are connected by weak π-π interactions between the central naphthofuran benzene rings of neighbouring molecules, with a Cg···Cg ii distance of 3.483 (2) Å and an interplanar distance of 3.416 (2) Å resulting in a slippage of 0.680 (2) Å ( Fig. 2, Cg is the centroid of the C2/C3/C8/C9/C10/C11 benzene ring).

Experimental
77% 3-Chloroperoxybenzoic acid (202 mg, 0.9 mmol) was added in small portions to a stirred solution of 1-(4-bromophenylsulfanyl)-2-methylnaphtho [2,1-b]furan (295 mg, 0.8 mmol) in dichloromethane (40 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, 2:1 v/v) to afford the title compound as a colorless solid [yield 74%, m.p. 466-467 K; R f = 0.59 (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 = 0.95 Å for aryl and 0.98 Å for the methyl H atoms. Uiso(H) = 1.2U eq (C) for aryl and 1.5U eq (C) for methyl H atoms. The positions of the methyl H atoms were optimized rotationally. program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and DIAMOND (Brandenburg, 1998); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).    where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.002 Δρ max = 0.62 e Å −3 Δρ min = −0.60 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.