3-{[5-(4-Bromophenyl)imidazo[2,1-b][1,3,4]thiadiazol-2-yl]methyl}-1,2-benzoxazole

In the title compound, C18H11BrN4OS, the imidazothiadiazole and benzisoxazole rings are individually planar with maximum deviations of 0.025 (3) 0.015 (4) Å, respectively, and are inclined at an angle of 23.51 (7)° with respect to each other. The planes of the imidazothiadiazole and bromophenyl rings are inclined at an angle of 27.34 (3)°. In the crystal, intermolecular C—H⋯N interactions result in chains of molecules along the b and c axes. Moreover, C—H⋯O interactions result in centrosymmetric head-to-head dimers with R 2 2(24) graph-set motifs. The molecular packing is further stabilized by π–π stacking interactions between the imidazole rings with a shortest centroid–centroid distance of 3.492 (3) Å. In addition, C—H⋯π interactions are observed in the crystal structure.

In the title compound, C 18 H 11 BrN 4 OS, the imidazothiadiazole and benzisoxazole rings are individually planar with maximum deviations of 0.025 (3) 0.015 (4) Å , respectively, and are inclined at an angle of 23.51 (7) with respect to each other. The planes of the imidazothiadiazole and bromophenyl rings are inclined at an angle of 27.34 (3) . In the crystal, intermolecular C-HÁ Á ÁN interactions result in chains of molecules along the b and c axes. Moreover, C-HÁ Á ÁO interactions result in centrosymmetric head-to-head dimers with R 2 2 (24) graph-set motifs. The molecular packing is further stabilized bystacking interactions between the imidazole rings with a shortest centroid-centroid distance of 3.492 (3) Å .
In addition, C-HÁ Á Á interactions are observed in the crystal structure.

Experimental
The title compound was synthesized by following the procedure reported earlier (Lamani et al., 2009) and suitable crystals for X-ray crystallographic analysis were grown from a solution of dimethylformamide by slow evaporation at room temperature.

Special details
Experimental. The compound was synthesized by following the procedure given in Lamani et al., (2009) 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 cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s 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.