(±)-2-{3-[1-(2,4-Difluorophenyl)ethyl]-1,3-thiazolidin-2-ylidene}malononitrile

In the title compound, C14H11F2N3S, the heterocyclic five-membered ring has an envelope conformation. Although the molecule is chiral, the compound is a racemate (R/S). There is a weak intermolecular C—H⋯π interaction but no classical hydrogen bonds are observed in the crystal structure.

In the title compound, C 14 H 11 F 2 N 3 S, the heterocyclic fivemembered ring has an envelope conformation. Although the molecule is chiral, the compound is a racemate (R/S). There is a weak intermolecular C-HÁ Á Á interaction but no classical hydrogen bonds are observed in the crystal structure.
Cg is the centroid of the benzene ring.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: DN2699).

Comment
It has been reported that both thiazoles and thiazolidines have good and wide insecticidal, fungicidal, herbicidal and acaricidal activities (Melnikov, et al., 1979;Kratt et al., 1986). As part of our search for compounds with good herbicidal and fungicidal activity, the title compound, (I), was synthesized.
The reaction mixture is filtered, and the solution is concentrated under reduced pressure to give the title compound (I) 27.2 g (92% yield). (Hense, et al., 2002). Single crystals suitable for X-ray measurement were obtained by recrystallization from the tetrahydrofuran solution of (I) at room temperature.

Refinement
All C-bound H atoms were placed in calculated positions, with C-H = 0.95-1.00 Å, and included in the final cycles of refinement using a riding model, with U iso (H) = 1.2U eq (C) for the aryl and methylene H atoms and 1.5U eq (C) for methyl H atoms.

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 supplementary materials sup-3 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 > σ(F 2 ) is used only for calculating Rfactors(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.