Crystal structure and Hirshfeld surface analysis of dimethyl 2-oxo-4-(pyridin-2-yl)-6-(thio-phen-2-yl)cyclo-hex-3-ene-1,3-di-carboxyl-ate.

In the title compound, C19H17NO5S, the cyclo-hexene ring adopts nearly an envelope conformation. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds, forming a three-dimensional network. In addition, C-H⋯π inter-actions connect the mol-ecules by forming layers parallel to the (010) plane. According to the Hirshfeld surface analysis, H⋯H (36.9%), O⋯H/H⋯O (31.0%), C⋯H/H⋯C (18.9%) and S⋯H/H⋯S (7.9%) inter-actions are the most significant contributors to the crystal packing.

Crystal structure and Hirshfeld surface analysis of 1-(2-amino-4-methyl-1,3-thia-zol-5-yl)ethan-1-one.

In the title compound, C6H8N2OS, all atoms except for the methyl H atoms are coplanar, with a maximum deviation of 0.026 (4) Å. In the crystal, pairs of mol-ecules are linked by N-H⋯N hydrogen bonds, forming R 2 2(8) ring motifs. Dimers are connected by N-H⋯O hydrogen bonds, forming layers parallel to the (102) plane. Consolidating the mol-ecular packing, these layers are connected by C-H⋯π inter-actions between the center of the 1,3-thia-zole ring and the H atom of the methyl group attached to it, as well as C=O⋯π inter-actions between the center of the 1,3-thia-zole ring and the O atom of the carboxyl group. According to a Hirshfeld surface study, H⋯H (37.6%), O⋯H/H⋯O (16.8%), S⋯H/H⋯S (15.4%), N⋯H/H⋯N (13.0%) and C⋯H/H⋯C (7.6%) inter-actions are the most significant contributors to the crystal packing.

Crystal structure and Hirshfeld surface analysis of 2-amino-5-{(1E)-1-[(carbamo-thioyl-amino)-imino]eth-yl}-4-methyl-1,3-thia-zol-3-ium chloride monohydrate.

In the hydrated title salt, C7H12N5S2 +·Cl-·H2O, the asymmetric unit comprises one 2-amino-5-{(1E)-1-[(carbamo-thioyl-amino)-imino]-eth-yl}-4-methyl-1,3-thia-zol-3-ium cation, one chloride anion and one water mol-ecule of crystallization. The cation is nearly flat (r.m.s. deviation of non-H atoms is 0.0814 Å), with the largest deviation of 0.1484 (14) Šobserved for one of the methyl C atoms. In the crystal, the cations are linked by O-H⋯Cl, N-H⋯Cl, N-H⋯O, N-H⋯S and C-H⋯S hydrogen bonds, forming a tri-periodic network. The most important contributions to the crystal packing are from H⋯H (35.4%), S⋯H/H⋯S (24.4%), N⋯H/H⋯N (8.7%), Cl⋯H/H⋯Cl (8.2%) and C⋯H/H⋯C (7.7%) inter-actions.

Crystal structure and Hirshfeld surface analysis of 2-amino-4-(4-meth-oxy-phen-yl)-6-oxo-1-phenyl-1,4,5,6-tetra-hydro-pyridine-3-carbo-nitrile.

The central tetra-hydro-pyridine ring of the title compound, C19H17N3O2, adopts a screw-boat conformation. In the crystal, strong C-H⋯O and N-H⋯N hydrogen bonds form dimers with R 2 2(14) and R 2 2(12) ring motifs, respectively, between consecutive mol-ecules along the c-axis direction. Inter-molecular N-H⋯O and C-H⋯O hydrogen bonds connect these dimers, forming a three-dimensional network. C-H⋯π inter-actions and π-π stacking inter-actions contribute to the stabilization of the mol-ecular packing. A Hirshfeld surface analysis indicates that the contributions from the most prevalent inter-actions are H⋯H (47.1%), C⋯H/H⋯C (20.9%), O⋯H/H⋯O (15.3%) and N⋯H/H⋯N (11.4%).

Crystal structure and Hirshfeld surface analysis of 3-cyano-4-hy-droxy-2-(4-methyl-phen-yl)-6-oxo-N-phenyl-4-(thio-phen-2-yl)cyclo-hexane-1-carbox-amide 0.04-hydrate.

In the title compound, C25H22N2O3S·0.04H2O, the central cyclo-hexane ring adopts a chair conformation. In the crystal, mol-ecules are linked by N-H⋯O, C-H⋯O, and C-H⋯N hydrogen bonds, forming the mol-ecular layers parallel to the bc plane, which inter-act by the van der Waals forces between them. A Hirshfeld surface analysis indicates that the contributions from the most prevalent inter-actions are H⋯H (41.2%), C⋯H/H⋯C (20.3%), O⋯H/H⋯O (17.8%) and N⋯H/H⋯N (10.6%).

Ethyl 4-(5-bromo-2-hy-droxy-phen-yl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexa-hydro-quinoline-3-carboxyl-ate.

In the title compound, C21H24BrNO4, the dihedral angle between the heterocyclic ring and the pendant aromatic ring is 80.20 (13)°. The hexahydroquinone [i.e. the one with the C=O group] ring adopts a sofa conformation. An intra-molecular O-H⋯O hydrogen bond generates an S(6) ring motif. The ethyl group is disordered over two sets of sites with a refined site occupancy ratio of 0.633 (10):0.366 (10). In the crystal, mol-ecules are linked by N-H⋯O inter-actions, forming chains parallel to [101]. There are no significant C-H⋯π or π-π inter-actions in the crystal structure.

Ethyl 2,7,7-trimethyl-5-oxo-4-phenyl-1,4,5,6,7,8-hexa-hydro-quinoline-3-carboxyl-ate.

In the title compound, C(21)H(25)NO(3), the hydro-pyridine ring that constitutes a part of the hexa-hydro-quinoline fused-ring system adopts a sofa conformation; the methine C atom deviates from the least-squares plane defined by the remaining five non-H atoms (r.m.s. deviation = 0.088 Å) by 0.454 (3) Å. The phenyl ring is aligned at 85.5 (1)° with respect to this mean plane. In the crystal, adjacent molecules are linked via an N-H⋯O hydrogen bond, involving the amino group and the carbonyl O atom of the fused-ring system, forming chains running along [100]. The ethyl group is disordered over two positions in a 0.609 (6):0.391 (6) ratio.