2-Methyl-1-(4-methylphenylsulfonyl)naphtho[2,1-b]furan

In the title compound, C20H16O3S, the 4-methylphenyl ring makes a dihedral angle of 83.07 (3)° with the mean plane [r.m.s. deviation = 0.020 (1) Å] of the naphthofuran fragment. In the crystal, molecules are linked by weak C—H⋯O and C—H⋯π interactions.

In the title compound, C 20 H 16 O 3 S, the 4-methylphenyl ring makes a dihedral angle of 83.07 (3) with the mean plane [r.m.s. deviation = 0.020 (1) Å ] of the naphthofuran fragment. In the crystal, molecules are linked by weak C-HÁ Á ÁO and C-HÁ Á Á interactions.

Related literature
For background information and the crystal structures of related compounds, see: Choi et al. (2008Choi et al. ( , 2012 Table 1 Hydrogen-bond geometry (Å , ).
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: HB6696).
In the title molecule ( Fig. 1), the naphthofuran unit is essentially planar, with a mean deviation of 0.020 (1) Å from the least-squares plane defined by the thirteen constituent atoms. The dihedral angle between the 4-methylphenyl ring and the mean plane of the naphthofuran fragment is 83.07 (3)°. The crystal packing features weak C-H···O hydrogen bonds  Table 1). In addition, weak C-H···π interactions occur ( Fig. 2 & Table 1).

Experimental
77% 3-Chloroperoxybenzoic acid (448 mg, 2.0 mmol) was added in small portions to a stirred solution of 2-methyl-1-(4methylphenylsulfanyl)naphtho [2,1-b]furan (273 mg, 0.9 mmol) in dichloromethane (40 mL) at 273 K. After being stirred at room temperature for 10h, 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 (benzene) to afford the title compound as a colorless solid [yield 68%, m.p. 440-441 K; R f = 0.41 (benzene)]. Colourless blocks 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 methyl H atoms. Uiso(H) = 1.2U eq (C) for aryl and 1.5U eq (C) for methyl H atoms. The positions of methyl hydrogens were optimized rotationally.  The molecular structure of the title compound with displacement ellipsoids drawn at the 50% probability level. H 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 = 0.32 e Å −3 Δρ min = −0.49 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.