7-Bromo-1-(4-chlorophenylsulfanyl)-2-phenylnaphtho[2,1-b]furan

In the title compound, C24H14BrClOS, the S-bound 4-chlorophenyl ring is nearly perpendicular to the plane of the naphthofuran fragment [dihedral angle = 83.34 (3)°] and the phenyl ring in the 2-position is rotated out of the naphthofuran plane by a dihedral angle of 15.23 (5)°. The crystal structure is stabilized by aromatic π–π interactions between the furan and the central benzene rings of the neighbouring naphthofuran fragments, and between the outer benzene rings of the neighbouring naphthofuran fragments; the centroid–centroid distances within the stack are 3.879 (2) and 3.857 (2) Å. In addition, intermolecular C—Cl⋯π interactions [3.505 (2) Å] between the Cl atom and the 2-phenyl ring are present.

In the title compound, C 24 H 14 BrClOS, the S-bound 4-chlorophenyl ring is nearly perpendicular to the plane of the naphthofuran fragment [dihedral angle = 83.34 (3) ] and the phenyl ring in the 2-position is rotated out of the naphthofuran plane by a dihedral angle of 15.23 (5) . The crystal structure is stabilized by aromaticinteractions between the furan and the central benzene rings of the neighbouring naphthofuran fragments, and between the outer benzene rings of the neighbouring naphthofuran fragments; the centroidcentroid distances within the stack are 3.879 (2) and 3.857 (2) Å . In addition, intermolecular C-ClÁ Á Á interactions [3.505 (2) Å ] between the Cl atom and the 2-phenyl ring are present.

Comment
Molecules bearing naphthofuran skeleton have attracted considerable interest in view of their biological activity (Hagiwara et al., 1999;Hranjec et al., 2003;Mahadevan & Vaidya, 2003). As a part of our continuing studies of the effect of side chain substituents on the solid state structures of 7-bromo-2-phenylnaphtho[2,1-b]furan analogues (Choi et al., 2009a, b), we report the crystal structure of the title compound (Fig. 1).

Experimental
Zinc chloride (273 mg, 2.0 mmol) was added to a stirred solution of 6-bromonaphthol (446 mg, 2.0 mmol) and 2-chloro-2-(4-chlorophenylsulfanyl)acetophenone (594 mg, 2.0 mmol) in dichloromethane (40 ml) at room temperature, and stirring was continued at the same temperature for 40 min. The reaction was quenched by the addition of water and the organic layer separated, dried over magnesium sulfate, filtered and concentrated in vacuum. The residue was purified by column chromatography (carbon tetrachloride) to afford the title compound as a colorless solid [yield 74%, m.p. 481-482 K; R f = 0.8 (carbon tetrachloride)]. Single crystals suitable for X-ray diffraction were prepared by 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 = 0.95 Å for aromatic H atoms and with U iso (H) = 1.20U eq (C) for aromatic 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.

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.