(E)-6-Bromo-3-{2-[2-(2-chlorobenzylidene)hydrazinyl]thiazol-5-yl}-2H-chromen-2-one dimethyl sulfoxide monosolvate

In the title compound C19H11N3O2SClBr·C2H6OS, the molecule adopts an E configuration about the central C=N double bond. The chromene ring system and the thiazole ring are approximately planar, with maximum deviations of 0.027 (2) and 0.003 (1) Å, respectively. The central thiazole ring makes dihedral angles of 21.82 (9) and 5.88 (7)° with the chloro-substituted phenyl ring and the chromene ring, respectively. In the crystal, molecules are connected via N—H⋯O, N—H⋯S and C—H⋯O hydrogen bonds, forming supramolecular chains along the c axis. An intramolecular C—H⋯O hydrogen bond occurs. π–π interactions are observed between the thiazole and phenyl rings [centroid–centroid distance = 3.6293 (10) Å]. A short Br⋯Cl contact of 3.37 (6) Å also occurs.

In the title compound C 19 H 11 N 3 O 2 SClBrÁC 2 H 6 OS, the molecule adopts an E configuration about the central C N double bond. The chromene ring system and the thiazole ring are approximately planar, with maximum deviations of 0.027 (2) and 0.003 (1) Å , respectively. The central thiazole ring makes dihedral angles of 21.82 (9) and 5.88 (7) with the chloro-substituted phenyl ring and the chromene ring, respectively. In the crystal, molecules are connected via N-HÁ Á ÁO, N-HÁ Á ÁS and C-HÁ Á ÁO hydrogen bonds, forming supramolecular chains along the c axis. An intramolecular C-HÁ Á ÁO hydrogen bond occurs.interactions are observed between the thiazole and phenyl rings [centroid-centroid distance = 3.6293 (10) Å ]. A short BrÁ Á ÁCl contact of 3.37 (6) Å also occurs.

Comment
Coumarin derivatives have remarkable medicinal value due to their potential chemotherapeutic (Liebig et al., 1974), fungicidal (Pathak et al., 1981), antiviral (Hwu et al., 2008) and anticoagulant (Lee et al., 2003) properties. Furthermore, coumarins with a variety of substituted thiazole rings exhibit promising biological activities. Recently, some coumarins incorporating thiazolyl semicarbazones which act as anticonvulsant agents were reported (Siddiqui et al., 2009). The title compound (I) is a new derivative of hydrazinyl thiazolyl coumarin. We present here its crystal structure.

Refinement
Atoms H11 and H1N1 were located from a difference Fourier map and refined freely [N-H = 0.95 (3) Å]. The remaining H atoms were positioned geometrically [C-H = 0.93 or 0.96 Å] and were refined using a riding model, with U iso (H) = 1.2 or 1.5 U eq (C). A rotating group model was applied to the methyl groups. The highest residual electron density peak is located at 0.78 Å from Br1 and the deepest hole is located at 0.68 Å from Br1.

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.