2-(2,4-Di-chloro-phen-oxy)-N'-[2-(2,4-di-chloro-phen-oxy)acet-yl]acetohydrazide.

The complete mol-ecule of the title compound, C16H12Cl4N2O4, is generated by a crystallographic centre of symmetry. In the crystal, N-H⋯O hydrogen bonds link the mol-ecules into [010] chains featuring R 2 2(10) loops. The chains are cross-linked by short Cl⋯N contacts [3.224 (2) Å].

2-(Naphthalen-2-yl-oxy)-N'-[2-(naphthalen-2-yl-oxy)acet-yl]acetohydrazide monohydrate.

The title compound, C24H20N2O4·H2O, crystallizes with half a mol-ecule of 2-(naphthalen-2-yl-oxy)-N'-[2-(naphthalen-2-yl-oxy)acet-yl]acetohydrazide and half a water mol-ecule in the asymmetric unit. In the crystal, mol-ecules form planes parallel to (011). Two mol-ecules are connected by water mol-ecules via O-H⋯O and N-H⋯O hydrogen bonds.

2-[3-(4-Chloro-phen-yl)-5-(4-fluoro-phen-yl)-4,5-di-hydro-1H-pyrazol-1-yl]-5-[(4-fluoro-phen-yl)diazen-yl]-4-methyl-thia-zole.

The mol-ecule of the title compound, C25H18ClF2N5S, comprises almost co-planar fluoro-phenyl, methyl-thia-zolyl, pyrazolyl and chloro-phenyl rings with the second fluoro-phenyl ring almost perpendicular to this plane. One fluoro-phenyl group is disordered over two components of occupancy ratio 0.767 (10):0.233 (10) related by a 24.2 (8)° twist. In the crystal, two mol-ecules related by inversion symmetry are linked by a pair of C-H⋯F contacts in an R(8)2 2 geometry.

Crystal structure of 2-cyclo-hexyl-1,3-thia-zolo[4,5-b]pyridine.

In the title compound, C12H14N2S, the cyclo-hexane ring adopts a chair conformation with the exocyclic C-C bond in an equatorial orientation. The mean plane through the cyclo-hexane ring (all atoms) is twisted from the thia-zolo-pyridine ring system (r.m.s. deviation = 0.013 Å) by 39.57 (6)°. In the crystal, mol-ecules form (100) sheets, although there are no specific directional inter-actions between them. The crystal stucture was refined as a two-component perfect twin.

Crystal structure of 2-(3-nitro-phen-yl)-1,3-thia-zolo[4,5-b]pyridine.

In the title compound, C12H7N3O2S, the dihedral angle between the planes of the thia-zolo-pyridine ring system (r.m.s. deviation = 0.005 Å) and the benzene ring is 3.94 (6)°. The nitro group is rotated by 7.6 (2)° from its attached ring. In the crystal, extensive aromatic π-π stacking [shortest centroid-centroid separation = 3.5295 (9) Å] links the mol-ecules into (001) sheets.

Crystal structure of 2-(2-methyl-phen-yl)-1,3-thia-zolo[4,5-b]pyridine.

In the title mol-ecule, C13H10N2S, the dihedral angle between the planes through the non-H atoms of the methylbenzene and thi-azo-lopyridine groups is 36.61 (5)°. In the crystal, the thi-azo-lopyridine groups of inversion-related mol-ecules overlap, with a minimum ring-centroid separation of 3.6721 (9) Å. Furthermore, the methylbenzene groups from neighbouring mol-ecules inter-act edge-to-face at an angle of 71.66 (5)°. In addition, weak C-H⋯ N hydrogen bonds form chains exending along [100].

Crystal structure of 3-amino-2-propyl-quinazolin-4(3H)-one.

In the title mol-ecule, C11H13N3O, the propyl group is almost perpendicular to the quinazolin-4(3H)-one mean plane, making a dihedral angle of 88.98 (9)°. In the crystal, mol-ecules related by an inversion centre are paired via π-π overlap, indicated by the short distances of 3.616 (5) and 3.619 (5) Šbetween the centroids of the aromatic rings of neighbouring mol-ecules. Inter-molecular N-H⋯N and N-H⋯O hydrogen bonds form R 6 (6)(30) rings and C(5) chains, respectively, generating a three-dimensional network. Weak C-H⋯O inter-actions are also observed.

Crystal structure of 3-amino-2-ethyl-quinazolin-4(3H)-one.

The mol-ecule of the title compound, C10H11N3O, is planar, including the ethyl group, as indicated by the N-C-C-C torsion angle of 1.5 (2)°. In the crystal, inversion-related mol-ecules are stacked along the a axis. Mol-ecules are oriented head-to-tail and display π-π inter-actions with a centroid-to-centroid distance of 3.6664 (8) Å. N-H⋯O hydrogen bonds between mol-ecules generate a 'step' structure through formation of an R 2 (2)(10) ring.

Crystal structure of 2,2-dimethyl-N-(pyridin-3-yl)propanamide.

In the title compound, C10H14N2O, the pyridine ring is inclined to the mean plane of the amide moiety [N-C(=O)C] by 17.60 (8)°. There is an intra-molecular C-H⋯O hydrogen bond present involving the carbonyl O atom. In the crystal, mol-ecules are linked via N-H⋯N hydrogen bonds, forming chains propagating along [100]. The tert-butyl group is disordered over two sets of sites with a refined occupancy ratio of 0.758 (12):0.242 (12).

Crystal structure of 2,2-dimethyl-N-(5-methyl-pyridin-2-yl)propanamide.

There are two mol-ecules in the asymmetric unit of the title compound, C11H16N2O. The pyridine rings and amide groups overlap almost perfectly (r.m.s. overlay fit = 0.053 Å), but the tertiary butyl groups have different orientations: in one mol-ecule, one of the methyl C atoms is syn to the amide O atom [O-C-C-C = -0.8 (3)°] and in the other the equivalent torsion angle is 31.0 (2)°. In the crystal, the two independent mol-ecules are linked by a pair of N-H⋯N hydrogen bonds in the form of an R 2 (2)(8) loop to form a dimer. A C-H⋯O inter-action connects the dimers into [100] chains.