4-(5-tert-Butyl-1,3-dithian-2-yl)-5-chloro-2-phenyl-1,3-oxazole

In the title molecule, C17H20ClNOS2, the phenyl and oxazole rings are nearly coplanar with an average deviation of 0.022 Å from the mean plane (M). The 1,3-dithiane ring adopts a chair conformation and is twisted in such a way that the C—CBu fragment lies in M (deviations are 0.031 and 0.010 Å, respectively, for the two C atoms).

In the title molecule, C 17 H 20 ClNOS 2 , the phenyl and oxazole rings are nearly coplanar with an average deviation of 0.022 Å from the mean plane (M). The 1,3-dithiane ring adopts a chair conformation and is twisted in such a way that the C-C Bu fragment lies in M (deviations are 0.031 and 0.010 Å , respectively, for the two C atoms).  4-(5-tert-Butyl-1,3-dithian-2-yl)-5-chloro-2-phenyl-1,3-oxazole Y. Cui, L. Liu, M. Liu, Y. Duan and S. Liu Comment γ-Aminobutyric acid (GABA) receptor of insect exists in their nerve cell and intramuscular cell, and a combinative site of many insecticide and active compounds (Wacher et al., 1992). A large number of related structural series (e.g., trioxabicyclooctanes, thiazines, arylpyrimidines, oxathianes, and dithianes) was synthesized and assayed on GABA receptor to discover novel insecticides (Jeffrey, 2003). Until now, only synthetic compound Fipronil is broadly used to control certain species of insects that have become resistant to most insecticides (Naratashi et al., 2007). In order to further optimize 1,3-dithiane derivative, the title compound, (I), was synthesized. Herewith we present its crystal structure.

Related literature
In the title molecule, the phenyl and oxazole rings are nearly coplanar with the average deviation of 0.022 Å from the mean plane (M). The 1,3-dithiane ring adopts a chair conformation being twisted in such a way, that two-atomic fragment C12-C14 actually lie in M with deviations of 0.031 and 0.010 Å, respectively. The crystal structure exhibits no classical hydrogen bonds.

Experimental
Compound (I) was prepared by the 4 h reaction of 0.8 g (3.85 mmol) of 5-chloro-2-phenyloxazole-4-carbaldehyde and 0.8 g (4.88 mmol) of 2-tert-butylpropane-1,3-dithiol in the presence of two drops formic acid used as a catalyst at room temperature with stirring. The resulting mixture was dissolved in chloroform (60 ml), washed with aqueous 10% NaOH (3×20 ml) and H 2 O (3×20 ml), and then dried with anhydrous sodium sulfate. After concentration, the residue was purified by re-crystallization in a mixed solvent of ethyl acetate and petroleum ether. Single crystals suitable for X-ray data collection were obtained by re-crystallization of the crude product from a mixed solvent ethyl acetate and petroleum ether (v/v, 1/20) as a light yellow crystalline solid (60%), m.p. 453 K.

Refinement
The H atoms were positioned with idealized geometry (C-H 0.93-0.98 Å), and refined using a riding model with U iso (H)=1.2 or 1.5U eq (C). Fig. 1. The molecular structure of (I), with atomic labels and 30% probability displacement ellipsoids for non-H atoms.

Special details
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s 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.