S-Phenyl 4-methoxybenzothioate

In the molecule of the title thioester, C14H12O2S, the dihedral angle between the phenyl and benzene rings is 71.8 (3)°. The methoxy group is essentially coplanar with the benezene ring to which it is bonded, with an r.m.s. deviation of 0.0065 (5) Å for the non-H atoms involved. In the crystal, weak C—H⋯π interactions are present.

In the molecule of the title thioester, C 14 H 12 O 2 S, the dihedral angle between the phenyl and benzene rings is 71.8 (3) . The methoxy group is essentially coplanar with the benezene ring to which it is bonded, with an r.m.s. deviation of 0.0065 (5) Å for the non-H atoms involved. In the crystal, weak C-HÁ Á Á interactions are present.
Cg1 is the centroid of the C1-C6 ring.
Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009  Thioesters are one of the most useful building blocks for organic transformations such as in application of C-C coupling for the synthesis of carbonyl compounds in asymmetric aldol reactions. Recently, the α-β-unsaturated thioester analogs have been successfully applied for asymmetric additions which allow the access to chiral intermediates for the synthesis of more complex compounds. Furthermore, they were used in natural product synthesis and also are acting as biologically relevant substances finding application for in vivo tumor suppression (Agapiou & Krische (2003); Barbero et al., 2003;Choi et al., 2003;Horst et al., 2007;Howell et al., 2006;Jew et al., 2003;Liebeskind & Srogl 2000;McGarvey et al., 1986;Ozaki et al., 2003;Shah et al., 2002;Yang & Drueckhammer, 2001). Owing to these applications of thioesters, the title compound (I) was synthesized. The molecule is chiral even though it has no chiral center as its mirror image cannot be superposed onto itself. The absolute configuration and crystal structure are reported. We have examined optically the batch of crystals and the morphology is the same for all the crystals in the batch thereby implying that there is no spontaneous resolution.
The crystal structure is consolidated by weak C-H···π interactions (Table 1).

Experimental
The title compound was synthesized according to El-Azab & Abdel-Aziz (2012). The trifluoroacetic acid (0.4 equiv) was added dropwise to a stirred solution of carboxylic acid (1 equiv) and thiophenol (1 equiv) in dry CH 3 CN (0.01 mol/l) over a period of 15 min at room temperature. After being stirred for 2-5 h at 333 K, the mixture was quenched by adding ammonium chloride solution (5 ml), extracted with ethylacetate, washed with brine and dried over anhydrous sodium sulfate. The product obtained after the evaporation of the solvent was purified by colum chromatography using mixture of hexane and CHCl 3 as eluent. The crystal was obtained by slow evaporation of the eluent system hexane and CHCl 3 ;

Refinement
All H atoms were placed in calculated positions with d(C-H) = 0.93 for aromatic and 0.96 Å for CH 3 atoms. The U iso values were constrained to be 1.5U eq of the carrier atom for methyl H atoms and 1.2U eq for the remaining H atoms. A rotating group model was used for the methyl groups. 1811 Friedel pairs were used to determine the absolute configuration.

S-Phenyl 4-methoxybenzothioate
Friedel pairs Flack parameter: 0.07 (5) 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.