Ethyl 2-(4-chloro-2-oxo-2,3-dihydro-1,3-benzothiazol-3-yl)acetate

In the molecule of the title compound, C11H10ClNO3S, the benzene and thiazole rings are oriented at a dihedral angle of 1.25 (3)°. Intramolecular C—H⋯O and C—H⋯Cl interactions result in the formation of two five-membered rings which both adopt envelope conformations.

In the molecule of the title compound, C 11 H 10 ClNO 3 S, the benzene and thiazole rings are oriented at a dihedral angle of 1.25 (3) . Intramolecular C-HÁ Á ÁO and C-HÁ Á ÁCl interactions result in the formation of two five-membered rings which both adopt envelope conformations.

Comment
The title compound is widely used in preventing cole from pest and is also useful to kill broad-leaved weed. It is likely to be decomposed in the soil. We report herein the crystal structure of the title compound.
In the molecule of the title compound ( Fig. 1), the bond lengths (Allen et al., 1987) and angles are within normal ranges.

Experimental
For the preparation of the title compound, 4-chlorobenzothiazol-2(3H)-one (10.7 g, 57.5 mmol), ethyl choroacetate (4.3 g, 50 mmol), and the catalyst of potassium iodide (0.63 g, 3 mmol) were added to butyl acetate solution (200 ml) of potassium carbonate (2.72 g, 20 ml) as acid-binding at 353 K. It was stirred for 8 h, and then cooled to room temperature. Water (150 ml) was added to dissolve the product, and inorganic salts were generated. The separated aqueous phase was extracted three times by butyl acetate, and then combined with organic phase product, treated with vacuum distillation at 353 K. Some anhydrous ethanol (about 40 ml) was added to the residual products, the combination was heated into homogeneous phase.
Thereafter, precipitated products were cooled (Shao et al., 2001). Crystals suitable for X-ray analysis were obtained by evaporating the solvent slowly at room temperature for about 15 d.

Refinement
H atoms were positioned geometrically, with C-H = 0.93, 0.97 and 0.96 Å for aromatic, methylene and methyl H, respectively, and constrained to ride on their parent atoms, with U iso (H) = xU eq (C), where x = 1.5 for methyl H and x = 1.2 for all other H atoms. supplementary materials sup-2 Ethyl 2-(4-chloro-2-oxo-2,3-dihydro-1,3-benzothiazol-3-yl)acetate as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq  0.59357 (6)