2-(4-Fluorophenyl)-2-oxoethyl 2-methoxybenzoate

In the title compound, C16H13FO4, the aromatic rings enclose an angle of 73.68 (6)°. In the crystal, C—H⋯O and C—H⋯F contacts connect the molecules into a three-dimensional network. The shortest intercentroid distance between two aromatic π-systems is 3.6679 (7) Å and is apparent between the fluorinated phenyl groups.

In the title compound, C 16 H 13 FO 4 , the aromatic rings enclose an angle of 73.68 (6) . In the crystal, C-HÁ Á ÁO and C-HÁ Á ÁF contacts connect the molecules into a three-dimensional network. The shortest intercentroid distance between two aromatic -systems is 3.6679 (7) Å and is apparent between the fluorinated phenyl groups.

Comment
Phenacyl benzoates are very useful protecting groups which can easily be cleaved by non-chemical methods. The advantage of photosensitive blocking groups in general is that they can be removed under completely neutral and mild conditions (Sheehan & Umezaw, 1973;Ruzicka et al., 2002;Litera et al., 2006) and therefore used for the identification of organic acids (Rather & Reid, 1919), synthesis of oxazoles, imidazoles (Huang et al., 1996) and benzoxazepine (Gandhi et al., 1995).
Keeping this in view, the title compound was synthesized to study its crystal structure.
The title compound is the ester derived of 2-methoxybenzoic acid and 1-(4-fluorophenyl)-2-hydroxyethanone. The leastsquares planes defined by the carbon atoms of the two individual aromatic systems intersect at an angle of 73.68 (6)°. The dihedral angle defined by the CO atoms of both carbonyl groups was found at more than 102° (Fig. 1).
In the crystal, C-H···O contacts as well as C-H···F contacts whose range falls invariably by more than 0.1 Å below the sum of van-der-Waals radii of the respective atoms are present. The C-H···O contacts are apparent between both hydrogen atoms in ortho position to the fluorine atom on the phenyl group and have the two different carbonyl groups as acceptors.
The C-H···F contact is supported by the hydrogen atom in ortho position to the carboxylic acid group on the second aromatic system. Details about metrical parameters as well as information about the symmetry of these contacts is summarized in Table 1. In terms of graph-set analysis (Etter et al., 1990;Bernstein et al., 1995), the descriptor for the C-H···O contacts is C 1 1 (6)R 2 2 (18) on the unitary level while the C-H···F contacts require a R 2 2 (24) descriptor on the same level. In total, the molecules are connected to a three-dimensional network. The shortest intercentroid distance between two π-systems was measured at 3.6679 (7) Å and is apparent between the fluorinated phenyl groups (Fig. 2).
The packing of the title compound in the crystal structure is shown in Figure 3.

Refinement
Carbon-bound H atoms were placed in calculated positions (C-H 0.95 Å for aromatic carbon atoms and C-H 0.99 Å for methylene groups) and were included in the refinement in the riding model approximation, with U(H) set to 1.2U eq (C). The H atoms of the methyl groups were allowed to rotate with a fixed angle around the C-C bond (C-H 0.98 Å) to best fit the experimental electron density (HFIX 137 in the SHELX program suite (Sheldrick, 2008)), with U(H) set to 1.5U eq (C).  Fig. 1. The molecular structure of the title compound, with atom labels and anisotropic displacement ellipsoids drawn at the 50% probability level.