Methyl (Z)-2-[(2,4-dioxothiazolidin-3-yl)methyl]-3-(2-methylphenyl)prop-2-enoate

The C=C bond in the title compound, C15H15NO4S, has a Z configuration. The thiazolidine ring is essentially planar [maximum deviation = 0.008 (1) Å for the N atom] and is oriented at a dihedral angle of 59.1 (1)° with respect to the benzene ring. In the crystal, pairs of C—H⋯O hydrogen bonds link centrosymmetrically related molecules into dimers, generating R 2 2(18) ring motifs. The crystal packing is further stabilized by C—H⋯π and C—O⋯π [O⋯centroid = 3.412 (2) Å and C—O⋯centroid = 115.0 (1)°] interactions.

The C C bond in the title compound, C 15 H 15 NO 4 S, has a Z configuration. The thiazolidine ring is essentially planar [maximum deviation = 0.008 (1) Å for the N atom] and is oriented at a dihedral angle of 59.1 (1) with respect to the benzene ring. In the crystal, pairs of C-HÁ Á ÁO hydrogen bonds link centrosymmetrically related molecules into dimers, generating R 2 2 (18) ring motifs. The crystal packing is further stabilized by C-HÁ Á Á and C-OÁ Á Á [OÁ Á Ácentroid = 3.412 (2) Å and C-OÁ Á Ácentroid = 115.0 (1) ] interactions.

Experimental
A solution of thiazolidine-2,4-dione (1 mmol, 0.117 g) and potassium carbonate (1.5 mmol, 0.207 g) in acetonitrile solvent was stirred for 15 minutes at room temperature. To this solution, (Z)-methyl-2 -(bromomethyl)-3-(2-methylphenyl)-prop-2enoate (1 mmol, 0.269 g) was added dropwise till the addition is complete. After the completion of the reaction, as indicated by TLC, acetonitrile was evaporated. Ethyl acetate (15 ml) and water (15 ml) were added to the crude mass. The organic layer was dried over anhydrous sodium sulfate. Removal of solvent led to the crude product, which was purified through pad of silica gel (100-200 mesh) using ethylacetate and hexanes (1:9) as solvents. The pure title compound was obtained as a colourless solid (0.290 g, 95% yield). Recrystallization was carried out using ethylacetate as solvent.
supplementary materials sup-2 Refinement H atoms were positioned geometrically, with C-H = 0.93-0.97 Å and constrained to ride on their parent atom, with U iso (H)=1.5U eq for methyl H atoms and 1.2U eq (C) for other H atoms. Fig. 1. The molecular structure of the title compound with the atom numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. H atoms are presented as a small spheres of arbitrary radius.

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.