N-(2,4-Dioxo-1,3-thiazolidin-3-yl)-2-(4-isobutylphenyl)propanamide

In the title compound, C16H20N2O3S, the thiazolidine ring is approximately planar [maximum deviation = 0.020 (2) Å] and forms a dihedral angle of 86.20 (11)° with the benzene ring. The mean plane through the propanamide unit forms dihedral angles of 88.54 (12) and 76.36 (12)°, respectively, with the thiazolidine and benzene rings. In the crystal structure, molecules are linked into chains along the a axis by N—H⋯O interactions. These chains are interconnected into two-dimensional arrays parallel to the ab plane by three different C—H⋯O interactions. The crystal structure is further stabilized by weak intermolecular C—H⋯π and N⋯O [2.713 (2) Å] interactions.


Comment
The synthesis of compounds incorporating ibuprofen has been attracting widespread attention due to their diverse pharmacological properties, such as anti-microbial, anti-inflammatory, analgesic and anti-tumor activities (Palaska et al., 2002;Aktay et al., 2005). There are numerous biologically active molecules with five-membered rings, containing two heteroatoms.
For example, thiazolidine is an important scaffold known to be associated with several biological activities (Verma & Saraf, 2008). In view of the above, the synthesis of a new series of 2,4-dioxo-1,3-thiazolidins containing ibuprofen was undertaken.
We report here one of these crystal structures, (I).
Single crystals were obtained by slow evaporation from an ethanol solution of (I). Yield was 84 %. M.p. 466 K.

Figures
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.