3-Benzyl-2-(furan-2-yl)-1,3-thiazolidin-4-one

In the title compound, C14H13NO2S, the thiazolidine ring is approximately planar with a maximum deviation of 0.112 (1) Å. The furan ring is disordered over two orientations, with an occupancy ratio of 0.901 (5):0.099 (5). The central thiazolidine ring makes dihedral angles of 85.43 (8), 87.50 (11) and 87.9 (9)° with the phenyl ring and the major and minor components of the disordered furan ring, respectively. In the crystal, molecules are connected by weak intermolecular C—H⋯O hydrogen bonds, forming supramolecular chains parallel to the b axis.


Comment
One of the main objectives of organic and medicinal chemistry is the design, synthesis and production of molecules having value as human therapeutic agents. During the past decade, combinatorial chemistry has provided access to chemical libraries based on privileged structures with heterocyclic moiety receiving special attention as they belong to a class of compounds with proven utility in medicinal chemistry. There are numerous biologically active molecules with five membered rings containing two hetero atoms. Among them, thiazolidin-4-ones are the most extensively investigated class of compounds, which have many interesting activity profiles namely bactericidal (Dutta et al., 1990), antifungal (Jadhav & Ingle, 1978), anticonvulsant (Gursoy et al., 2005), anti-HIV (Rawal et al., 2007), antituberculotic (Shrivastava et al., 2005), COX-1 inhibitors (Look et al., 1996), inhibitors of the bacterial enzyme MurB (Anders et al., 2001), non-nucleoside inhibitors of HIV-RT (Barreca et al., 2001) and anti-histaminic agents (Diurno et al., 1992).

Experimental
To a well ground intimate mixture of triphenylphosphine (1.1 mmol) and furfuraldehyde, (1.0 mmol) in a microwave vial (10 ml) equipped with a magnetic stirring bar, benzylazide (0.2 g, 1.0 mmol) was added dropwise with stirring. Stirring was continued until liberation of nitrogen ceased and then mercaptoacetic acid, (1.1 mmol), was added to the above mixture and the reaction vessel was sealed with a septum. It was then placed into the cavity of a focused monomode microwave reactor (CEM Discover, benchmate) and operated at 150°C (temperature monitored by a built-in IR sensor), power 80W for 10 minutes. The reaction temperature was maintained by modulating the power level of the reactor. The reaction mixture was allowed to stand at room temperature. The residue was then purified by column chromatography on silica (petrolium/etherethylacetate, 94:6 v/v) to afford 3-benzyl-2-(furan-2-yl)thiazolidin-4-one. Yield: 0.36 g (94%); M.p: 150-151°C. Crystals suitable for X-ray analysis were obtained by slow evaporation of an ethanol solution.

Refinement
All hydrogen atoms were positioned geometrically [C-H = 0.93-0.98 Å] and were refined using a riding model, with U iso (H) = 1.2 U eq (C). The furan ring is disordered over two orientations, with an occupancy ratio of 0.901 (5)

Special details
Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K.
Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The 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 > 2σ(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.