(4-Fluorophenyl)(4-hydroxy-3-methylphenyl)methanone

In the title compound, C14H11FO2, the two benzene rings are not coplanar, with a dihedral angle of 57.45 (12)° between their planes. In the crystal, molecules are linked by an O—H⋯O hydrogen bond, forming a 21 helical chain along the b axis.


Comment
The great interest in the benzophenone substances is fundamentally due to their diverse biological and chemical properties. Benzophenone and related compounds have a wide variety of biological activities such as anti-fungal and antiinflammatory activities (Khanum et al., 2004;Selvi et al., 2003). The presence of various substituents in the benzophenone nucleus is essential in determining the quantitative structure-activity relationships of these systems. The competence of benzophenones as chemotherapeutic agents, especially as inhibitors of HIV-1 reverse transcriptase RT, cancer and inflammation, is well established. Their chemistry has been studied extensively. In addition, methylsubstituted benzophenones exhibit chemotherapeutical activity against fungi. Some studies were carried out to show that methyl-substituted benzophenones exhibit anti-fungal properties (Naveen et al., 2006). In view of its extensive background, the title compound was prepared and characterized by single-crystal X-ray diffraction.
In the molecular structure of the title compound ( Fig. 1

Experimental
The title compound was synthesized by a mixture of anhydrous aluminium chloride (0.03 mol) and 2-methyl-phenyl-4fluorobenzoate (0.02 mol) in dry nitrobenzene (40 ml) was protected from moisture by calcium chloride guard tube and refluxed at 80-900 °C with stirring for 45 min. At the end of this period the solution was cooled and decomposed by acidulated ice-cold water. Nitrobenzene was removed by steam distillation. The residual solid was crushed into powder, dissolved in ether and extracted with 10 percent sodium hydroxide. The basic aqueous solution was neutralized with 10 percent hydrochloric acid. The filtered solid was washed with distilled water and recrystallized from ethanol to afford pale yellow needles of (4-fluorophenyl)(4-hydroxy-3-methylphenyl)methanone.

Refinement
All H-atoms were located from difference maps and were positioned geometrically and refined using a riding model with C-H = 0.93-0.96 Å and O-H = 0.82 Å, and with U iso (H) = 1.2U eq (C aromatic ) or 1.5U eq (O, C methyl ). The data collection did not yield reflections with measurable intensity range as the crystal was diffracting a bit poorly. Hence, the range is slightly less (64.45° rather than the required 65°).

Figure 1
An ORTEP view of the title compound with the atom-labeling scheme. The thermal ellipsoids are drawn at the 50% probability level.  where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.007 Δρ max = 0.27 e Å −3 Δρ min = −0.36 e Å −3 Special details Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles Refinement. Refinement on F 2 for ALL reflections except those flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses 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 observed criterion of F 2 > σ(F 2 ) is used only for calculating -R-factor-obs 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.