Crystal structure of 4-acetylphenyl 3-methylbenzoate

The planes of the aromatic rings of the title compound, C16H14O3, make a dihedral angle of 82.52 (8)°. The acetyl group and the phenyl ring make a dihedral angle of 1.65 (1)°. In the crystal, the molecules are linked by C—H⋯O interactions, generating C(7) chains along the a-axis direction.

The molecular structure is stabilized by an intramolecular and the crystal packing by intermolecular C-H···O hydrogen bonds (Table 1 & Fig. 2).

S2. Experimental
A clean and dry 250ml two neck RB flask was fitted with a condenser and an addition funnel. 0.5 mol of 4-hydroxy acetophenone was taken and 200ml of chloroform was added to it with stirring. The reaction mixture was cooled at 5-10°c. 0.5 mol of meta-tolouyl chloride was added dropwise to the reaction mixture. Stirring was continued for another 15 mins and 0.5 mol of potassium carbonate was slowly added. The reaction was continued for 2 hours and monitored using TLC. The reaction mixture was transferred into a 1 l beaker and washed twice with water (2 x 250 ml). The chloroform layer was separated and washed with 10% NaOH solution (2x250ml). The chloroform layer was separated and dried with anhydrous sodium sulphate. The chloroform layer was then filtered and concentrated under reduced pressure using rotary vacuum. It was cooled and hexane was added to it. The solid which precipitated was filtered and the product was air dried. After purification the compound was recrystallised in CHCl 3 by slow evaporation method.

S3. Refinement
The hydrogen atoms were placed in calculated positions with C-H = 0.93Å to 0.96 Å, refined in the riding model with fixed isotropic displacement parameters: U iso (H) = 1.5U eq (C) for methyl groups and U iso (H) = 1.2U eq (C) for C aromatic . The methyl groups were allowed to rotate but not to tip.

Figure 1
The molecular structure of the title compound, showing the atomic numbering and displacement ellipsoids drawn at 30% probability level.

Figure 2
The crystal packing of the title compound viewed down the a axis. Intermolecular hydrogen bonds are shown as dashed lines. H-atoms not involved in H-bonds have been excluded for clarity. where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.043 Δρ max = 0.14 e Å −3 Δρ min = −0.19 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.