Afshan Banu

Synthesis and Crystal Structure of 2-(4-Fluorobenzyl)-6-Phenylimidazo[2,1-b][1,3,4]Thiadiazole-5-Carbaldehyde

The crystal and molecular structure of 2-(4-fluoro-benzyl)-6-phenyl-imidazo[2,1-b][1,3,4]thiadiazole-5-carbaldehyde is described. The compound crystallizes in the monoclinic space group P21/n with a = 7.419(3)Å, b = 8.287(3)Å, c = 25.734(10)Å, β = 91.686(8)°, V = 1,581.6(10)Å3, z = 4. The crystal structure is stabilized by intermolecular C-H…N, C-H…O, and C-H…F interactions.

3-{[6-(4-Chloro-phen-yl)imidazo[2,1-b][1,3,4]thia-diazol-2-yl]meth-yl}-1,2-benzoxazole.

In the title compound, C18H11ClN4OS, the benzisoxazole and imidazothiadiazole rings are inclined at an angle of 23.81 (7)° with respect to each other. The imidazothiadiazole and chlorophenyl rings make a dihedral angle of 27.34 (3)°. In the crystal, intermolecular C—H⋯N interactions generate a chain along the c axis and C—H⋯O interactions form centrosymmetric dimers resulting in an R 2 2(26) graph-set motif. Moreover, the C—H⋯N and S⋯N [3.206 (4) Å] interactions links the molecules into R(7) ring motifs. The packing is further stabilized by π–π stacking interactions between the thiadiazole rings with a shortest centroid–centroid distance of 3.497 (3) Å. In addition, C—H⋯π interactions are observed in the crystal structure

6-(4-Bromo­phen­yl)-2-(4-fluoro­benz­yl)imidazo[2,1-b][1,3,4]thia­diazole

In the title compound, C17H11BrFN3S, the imidazothiadiazole and bromophenyl rings are individually almost planar, with maximum deviations of 0.0215 (4) and 0.0044 (4) Å, respectively, and are inclined at an angle of 27.34 (3)° with respect to each other. The dihedral angle between the mean planes of the fluorobenzyl and imidazothiadiazole rings is 79.54 (3)°. The crystal structure is stabilized by intermolecular C—H⋯N interactions resulting in chains of molecules along the b axis.

2-Amino-6-methyl-4,5,6,7-tetra­hydro-1-benzothio­phene-3-carbonitrile

In the title compound, C10H12N2S, one of the C atoms of the cyclohexene ring (at position 6) and the methyl group attached to it are disordered over two sets of sites in a 0.650 (3):0.350 (3) ratio. The cyclohexene ring in both the major and minor occupancy conformers adopts a half-chair conformation. The thiophene ring is essentially planar (r.m.s. deviation = 0.05 Å). In the crystal, N—H⋯N hydrogen bonds involving the amino groups result in inversion dimers with R 2 2(12) graph-set motif. Further N—H⋯N hydrogen bonds involving the amino and carbonitrile groups generate zigzag chains along the a axis.

Synthesis and Crystal Structure Analysis of 2-(Fluorobenzyl)-6-(4-Nitrophenyl) Imidazo[2,1-b][1,3,4]Thiadiazole

Preparation of 2-(4-fluorobexzyl)-6-(4-nitrophenyl)imidazo[2,1-b][1,3,4]thiadiazole is described and its crystal structure is discussed. The compound crystallizes in the monoclinic space group C2/c with a = 39.941(6) Å, b = 5.698(2) Å, c = 13.272(5) Å β = 90.880°, V = 3020(2) Å3, z = 8. The crystal structure is stabilized by weak intermolecular C-H…N,C-H…O,C-H…S, and C-H…F interactions.

Crystal and Molecular Structure of 7-Methyl-5,6,7,8-tetrahydro[1]benzothieno[2,3-d]pyrimidin-4[3H]one

X-ray characterization of 7-methyl-5,6,7,8-tetrahydro[1]benzothieno [2,3-d]pyrimidin-4[3H]one is described. The compound crystallizes in the monoclinic space group P21/c with a=7.0013(2)A, b=8.3116(3)A, c=18.374(6)A, β=91.746(2)°, V=1068.76(6)A3, z=4. The structure was solved using the direct method and refined to reliability R-factor of 0.0639 using 3180 independent reflections The crystal structure is further stabilized by intermolecular C-H...N, N-H...N C-H...O, N-H...O, and π-π interactions.

3-{[6-(4-Chlorophenyl)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.

7-Methyl-5,6,7,8-tetra-hydro-1-benzo-thieno[2,3-d]pyrimidin-4-amine.

In the title compound, C11H13N3S, two of the C atoms of the cyclohexene ring and the methyl group attached to it are disordered over two sets of sites in a 0.544 (2):0.456 (2) ratio. The benzothiene and pyrimidine rings are almost coplanar with an angular tilt of 2.371 (9)° between them. The thiophene ring is essentially planar (r.m.s. deviation 0.05 Å), while the cyclohexene ring in both the major- and minor-occupancy conformers adopts a half-chair conformation. In the crystal structure, pairs of intermolecular N—H⋯N hydrogen bonds involving the amino groups result in centrosymmetric head-to-head dimers about inversion centres, corresponding to an R 2 2(8) graph-set motif. Further, N—H⋯N hydrogen bonding generates a two-dimensional hydrogen-bonded network perpendicular to the ac plane and running along the diagonal of the ac plane.

2-Amino-7-oxo-4,5,6,7-tetra-hydro-1-benzothio-phene-3-carbonitrile.

In the title compound, C9H8N2OS, the benzothiophene ring is substituted with amino, oxo and carbonitrile groups. The thiophene ring is essentially planar (r.m.s. deviation = 0.0003 Å), while the cyclohexene ring is in a half-chair conformation. In the crystal, N—H⋯O hydrogen bonds generate chains of molecules in a zigzag pattern along the b axis. Pairs of N—H⋯N hydrogen bonds form centrosymmetric head-to-head dimers about inversion centres, corresponding to an R 2 2(12) graph-set motif. In addition, rather weak N—H⋯S interactions are also present in the structure and the supramolecular assembly is further consolidated by π–π stacking interactions between the benzothiophene rings, disposed at a distance of 3.742 (3) Å.