(Biphenyl-4-yl)[2-(4-methylbenzoyl)phenyl]methanone

In the title compound, C27H20O2, the central benzene ring makes dihedral angles of 64.86 (7) and 70.35 (7)° with the methyl-substituted ring and the biphenyl ring system, respectively. The crystal packing is stabilized by intermolecular C—H⋯O interactions, which link the molecules into chains parallel to the b axis.

In the title compound, C 27 H 20 O 2 , the central benzene ring makes dihedral angles of 64.86 (7) and 70.35 (7) with the methyl-substituted ring and the biphenyl ring system, respectively. The crystal packing is stabilized by intermolecular C-HÁ Á ÁO interactions, which link the molecules into chains parallel to the b axis.  Table 1 Hydrogen-bond geometry (Å , ). VS and DV thank the TBI X-ray facility, CAS in Crystallography and Biophysics, University of Madras, India, for the data collection and the UGC SAP for financial support.

Comment
Various biphenyl derivatives are used in the synthesis of pharmaceuticals, antifungal agents like bifonazole, optical brightening agents, dyes and polychlorinated biphenyls (PCBs). PCBs are used as heat-transfer agents, as electric insulators and are environmental pollutants causing carcinogenesis (Kucybala & Wrzyszczynski, 2002). Diketones are popular in organic synthesis for their applications in biology and medicine. They are known to exhibit antioxidants, antitumour and antibacterial activities (Bennett et al.,1999). They are also key intermediates in the preparation of various heterocyclic compounds (Sato et al., 2008).
X-ray analysis confirms the molecular structure and atom connectivity of the title compound as illustrated in the Fig. 1.
The crystal packing is stabilized by C-H···O intermolecular interaction (Table 1). The C16-H16···O1 i interaction generates a C6 chain parallel to b axis (symmetry code: x, y-1, z). The packing of the title compound is shown in Fig. 2.

Experimental
The furan (1 g) was dissolved in THF. The weighed lead tetracetone (1.52 g, 1520 mmol) was added to the furan. Then it was refluxed at 343 K for 0.5 h. The reaction mixture was analyzed by TLC. Then the usual workup was done with brine solution and CHCl 3 followed by column chromatography (10% 10% AcOEt/hexane) which lead to the solution of the pure compound. Single crystals suitable for X-ray diffraction were obtained by slow evaporation of a solution of the title compound in ethyl acetate at room temperature.

Refinement
The hydrogen atoms were placed in calculated positions with C-H = 0.93Å to 0.96Å and refined in the riding model with fixed isotropic displacement parameters: U iso (H) = 1.5U eq (C) for the methyl group and U iso (H) = 1.2U eq (C) for other H atoms. Fig. 1

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.