Crystal structures of ethyl {2-[4-(4-iso-propyl-phen-yl)thia-zol-2-yl]phen-yl}carbamate and ethyl {2-[4-(3-nitro-phen-yl)thia-zol-2-yl]phen-yl}carbamate.

The title compounds, C21H22N2O2S (I) and C18H15N3O4S (II), are structural analogs of the alkaloid Thio-sporine B. Both mol-ecules adopt a near-planar V-shaped conformation, which is consolidated by intra-molecular N-H⋯N and C-H⋯O hydrogen bonds. The crystal structure of (I) consists of mlecular stacks along the a axis, in which the mol-ecules are linked to each other by π(S)⋯π(C) inter-actions. In the crystal of (II), mol-ecules are linked into chains by C-H⋯O hydrogen bonds and the chains are cross-linked into (100) sheets by π-π stacking inter-actions.

2-Phenyl-5,6,7,8-tetra-hydro-imidazo[2,1-b][1,3]benzo-thia-zole.

The title compound, C15H14N2S, crystallizes with two independent mol-ecules in the asymmetric unit. The central imidazo[2,1-b][1,3]benzo-thia-zole unit is planar (r.m.s. deviations of 0.010 and 0.008 Šfor the two independent mol-ecules). The fused tetra-hydro-hexane ring adopts a half-chair conformation. The phenyl substituent is twisted by 16.96 (13) and 22.89 (12)° relative to the central imidazo[2,1-b][1,3]benzo-thia-zole unit in the two mol-ecules. In the crystal, there are no significant intermolecular interactions present.

3-Bromo-2-[4-(methyl-sulfan-yl)phen-yl]-5,6,7,8-tetra-hydro-1,3-benzo-thia-zolo[3,2-a]imidazole.

In the title mol-ecule, C16H15BrN2S2, the central imidazo[2,1-b]thia-zole fragment is almost planar (r.m.s. deviation = 0.012 Å), and the fused 5,6,7,8-tetra-hydro-benzene ring adopts an unsymmetrical half-chair conformation. The dihedral angle between the imidazo[2,1-b]thia-zole and benzene planes is 18.25 (4)°. The terminal methyl-sulfanyl substituent lies practically within the benzene plane [the dihedral angle between the corresponding planes is 7.20 (10)°] and is turned toward the C-Br bond. In the crystal, mol-ecules form infinite chains along [100] via secondary Br⋯N inter-actions [3.1861 (16) Å]. The chains are arranged at van der Waals distances.

7-Nitro-2-phenyl-imidazo[2,1-b][1,3]benzo-thia-zole.

In the title mol-ecule, C15H9N3O2S, the central imidazo[2,1-b][1,3]benzo-thia-zole heterotricyclic unit is essentially planar (r.m.s. deviation = 0.021 Å). The terminal phenyl ring and nitro group are twisted by 9.06 (1) and 11.02 (4)°, respectively, from the mean plane of the heterotricycle. In the crystal, mol-ecules are linked by π-π stacking inter-actions into columns along [100]; the inter-planar distance between neighboring imidazo[2,1-b][1,3]benzo-thia-zole planes within the columns is 3.370 (2) Å. Furthermore, the columns interact with each other by secondary S⋯O [2.9922 (10) and 3.1988 (11) Å] inter-actions, forming a three-dimensional framework.

3-Bromo-7-meth-oxy-2-phenyl-imidazo[2,1-b][1,3]benzothia-zole.

In the title mol-ecule, C16H11BrN2OS, the central imidazo[2,1-b][1,3]benzothia-zole tricycle is essentially planar (r.m.s. deviation = 0.021 Å). The terminal phenyl ring is twisted at 36.18 (5)° from the mean plane of the tricycle. In the crystal, pairs of eak C-H⋯O hydrogen bonds link mol-ecules into centrosymmetric dimers, which are further packed into stacks along the a axis.

6-(4-Chloro-phen-yl)-3-methyl-imidazo[2,1-b]thia-zole.

In the title compound, C12H9ClN2S, the imidazo[2,1-b]thia-zole fragment is planar (r.m.s. deviation = 0.003 Å), and the benzene ring is twisted slightly [by 5.65 (6)°] relative to this moiety. In the crystal, mol-ecules are linked by π-π stacking inter-actions into columns along [010]. The mol-ecules within the columns are arranged alternatively by their planar rotation of 180°. Thus, in the columns, there are the two types of π-π stacking inter-actions, namely, (i) between two imidazo[2,1-b]thia-zole fragments [inter-planar distance = 3.351 (2) Å] and (ii) between an imidazo[2,1-b]thia-zole fragment and the phenyl ring [inter-planar distance = 3.410 (5) Å]. There are no short contacts between the columns.