5-(4-Methylphenyl)-3-phenylcyclohex-2-en-1-one

In the title compound, C19H18O, the cyclohexene ring has an envelope conformation with the methine C atom on the flap. The phenyl and methylphenyl rings form a dihedral angle of 85.93 (11)°. The crystal packing is consolidated by van der Waals forces and weak C—H⋯π interactions.

In the title compound, C 19 H 18 O, the cyclohexene ring has an envelope conformation with the methine C atom on the flap. The phenyl and methylphenyl rings form a dihedral angle of 85.93 (11) . The crystal packing is consolidated by van der Waals forces and weak C-HÁ Á Á interactions.   Table 1 Hydrogen-bond geometry (Å , ).
In this context, herein we report the synthesis and crystal structure of the title compound (I).
The crystal packing of (I) is stabilized by van der Waals forces and weak C-H···π interactions (Table 1, Fig. 2).

Experimental
To a solution of 222 mg (1 mmol) (2E)-3-(4-methylphenyl)-1-phenylprop-2-en-1-one in 40 ml e thanol, 100 mg of acetyl acetone was added in presence of 60 mg MeONa. The reaction mixture was refluxed for 7 h then cooled to room temperature (Diao & Stahl, 2011;González et al., 2009;Zhang et al., 2008). The excess solvent was removed under vacuum to afford the solid product which was filltered off and recrystallized from ethanol. The obtained crystals were in good quality (m.p. 343 K) for X-ray diffraction without further crystallization.

Refinement
All H atoms were positioned geometrically (C-H = 0.95-1.00 Å) and refined by using a riding model, and with U iso (H) = 1.2 (1.5 for methyl groups)U eq (C).  The molecular structure of the title compound with the atom numbering scheme. Displacement ellipsoids for non-H atoms are drawn at the 50% probability level.

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.