2-(4-Chlorophenyl)-2-oxoethyl naphthalene-1-carboxylate

In the title compound, C19H13ClO3, an ester of 1-naphthoic acid with an aromatic alcohol, the least-squares planes defined by the C atoms of the respective aromatic systems enclose an angle of 77.16 (3)°. In the crystal, C—H⋯O contacts connect the molecules into undulating sheets parallel to the bc plane.

In the title compound, C 19 H 13 ClO 3 , an ester of 1-naphthoic acid with an aromatic alcohol, the least-squares planes defined by the C atoms of the respective aromatic systems enclose an angle of 77.16 (3) . In the crystal, C-HÁ Á ÁO contacts connect the molecules into undulating sheets parallel to the bc plane.

Experimental
Data collection: APEX2 (Bruker, 2010); cell refinement: SAINT (Bruker, 2010); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012) and Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009 For decades, phenyl benzoate derivatives have found ample application in the identification of organic acids (Rather & Reid 1919). These compounds can be photolysed under neutral and mild conditions (Sheehan & Umezaw, 1973;Ruzicka et al., 2002;Litera et al., 2006). They also find application in the field of synthetic chemistry such as in the synthesis of oxazoles and imidazoles (Huang et al., 1996) as well as benzoxazepine (Gandhi et al., 1995). In continuation of our research focused on the crystal structures of medical compounds, the title compound was synthesized.
The planes defined by the atoms of the carboxy group on the one hand and the non-hydrogen atoms of the CH 2 -C═O moiety intersect at an angle of 77.9 (2) °. The least-squares planes defined by the carbon atoms of the respective aromatic systems enclose an angle of 77.16 (3) ° (Fig. 1).
In the crystal, intermolecular C-H···O contacts are observed whose range falls by more than 0.2 Å below the sum of van-der-Waals radii of the atoms participating. One of the hydrogen atoms of the chlorinated phenyl moiety and the oxygen atom of the keto group give rise to centrosymmetric dimers. Additionally, the hydrogen atom in para position to the carboxy moiety forms a C-H···O contact to the double bonded oxygen atom of exactly this group in a neighbouring molecule. In total, the molecules are connected to undulated sheets parallel bc. In terms of graph-set analysis (Etter et al., 1990;Bernstein et al., 1995), the descriptor for these contacts is C 1 1 (7)R 2 2 (10) on the unary level. Information about metrical parameters as well as the symmetry of those contacts has been summarized in Table 1. The shortest intercentroid distance between two aromatic systems was measured at 4.7603 (9) Å and is apparent between the two different rings in the naphthoic acid moiety and its symmetry-generated equivalents (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).

Figure 1
The molecular structure of the title compound, with atom labels and anisotropic displacement ellipsoids (drawn at 50% probability level).