In the title compound, C8H8Br2O2, all non-H atoms lie essentially in a common plane (r.m.s deviation of all fitted non-H atoms = 0.0330 Å). In the crystal, weak C—H⋯O hydrogen bonds connect the mol­ecules, forming chains which extend along the b-axis direction.

In the title compound, C19H16F3NO6, a quinoline derivative featuring an annealated furan substituent, the mean planes of the carb­oxy substituents are at an angle of 74.3 (2)°. In the crystal, C—H⋯O contacts result in undulating chains along [110]. C—H⋯F contacts also occur. The shortest centroid–centroid distance between rings is 3.3376 (7) Å, involving two furan rings of neighbouring mol­ecules.

In the title compound, C21H23N3O4S·H2O, the methyl­sulfanyl group is disordered over two sets of sites with site-occupancy factors of 0.631 (11) and 0.369 (11). The dihydro­pyridine ring adopts an E 4 conformation. In the crystal, classical O—H⋯N, O—H⋯O and N—H⋯O hydrogen bonds, as well as C—H⋯O and C—H⋯S contacts, connect the mol­ecules into a three-dimensional network.

In the title compound, C22H24ClN3O4, intra­molecular C—H⋯O and C—H⋯N hydrogen bonds form S(9) and S(7) ring motifs, respectively. The 1,4-dihydro­pyridine ring adopts a flattened boat conformation. The benzene ring makes a dihedral angle of 33.36 (6)° with the pyrazole ring. In the crystal, pairs of N—H⋯N hydrogen bonds link the mol­ecules into inversion dimers. The dimers are stacked in column along the a axis through N—H⋯O and C—H⋯N hydrogen bonds. The crystal packing also features C—H⋯π inter­actions involving the pyrazole ring.

In the title compound, C17H15ClO5, the benzene rings forms a dihedral angle of 74.45 (10)°. In the crystal, mol­ecules are linked into C(13) chains along [011] via C—H⋯O hydrogen bonds. The crystal packing also features short Cl⋯Cl contacts of 3.1253 (10) Å.

In the title compound, C14H11Cl2NO, the benzene rings form a dihedral angle of 3.14 (6)°. Overall, the mol­ecule is close to being planar (r.m.s. deviation for all the non-H atoms = 0.054 Å). No significant directional inter­molecular inter­actions are observed in the crystal structure.

In the title compound, C28H29N3O4·C2H6O, the benzene ring makes dihedral angles of 33.72 (13) and 32.86 (13)°, respectively, with the adjacent pyrazole and phenyl rings. In the crystal, the components are connected via inter­molecular N—H⋯O, N—H⋯N, O—H⋯O and C—H⋯O hydrogen bonds, forming a layer parallel to the bc plane.

In the title compound, C23H27N3O5, the pyrazole ring is inclined at dihedral angles of 38.16 (6) and 80.80 (6)°, respectively, to the least-squares planes of the benzene and dihydro­pyridine rings. In the crystal, adjacent mol­ecules are linked via a pair of N—H⋯N hydrogen bonds, forming an inversion dimer. The dimers are stacked in a column along the a axis through N—H⋯O hydrogen bonds. Intra- and inter­molecular C—H⋯N and C—H⋯O hydrogen bonds are also observed.

In the title compound, C23H29Cl2NO, the fluorene ring is essentially planar, with a maximum deviation from the mean plane of 0.041 (1) Å. The amine group adopts a pyramidal configuration, the sum of the bond angles being 336.2 (3)°. In the crystal, the mol­ecules are linked into dimers by inter­molecular O—H⋯N and C—H⋯O hydrogen bonds. Weak C—H⋯π and π–π [centroid–centroid distance = 3.7544 (7) Å] inter­actions are also observed.

In the title compound, C13H12N4OS, the dihedral angle between the triazole and naphthalene ring systems is 67.42 (5)°. In the crystal, adjacent mol­ecules are linked via two pairs of inter­molecular N—H⋯S inter­actions, forming R 2 2(8) and R 2 2(10) ring motifs. Weak C—H⋯S inter­actions generate infinite chains along [001] and the structure is further consolidated by C–H⋯π bonds and aromatic π⋯π stacking inter­actions [distance between the centroids of the triazole rings = 3.2479 (7) Å].

In the title compound, C9H9Cl2N3O, the semicarbazone group is approximately planar, with an r.m.s deviation from the mean plane of 0.011 (2) Å. The dihedral angle between the least-squares planes through the semicarbazone group and the benzene ring is 38.76 (9)°. The crystal structure is further stabilized by N—H⋯O and C—H⋯O hydrogen bonding.

In the title triazole compound, C10H12N4OS, the triazole ring is essentially planar [maximum deviation = 0.009 (1) Å] and forms a dihedral angle of 5.78 (4)° with the benzene ring. In the crystal structure, mol­ecules are linked into dimers by centrosymmetric N—H⋯S inter­actions. These dimers are linked into two-mol­ecule-wide tapes by N—H⋯N and S⋯S [3.2634 (3) Å] inter­actions. In addition, they are further inter­connected by weak N—H⋯S inter­actions into sheets parallel to the ab plane. The crystal structure is further stabilized by weak inter­molecular C—H⋯π inter­actions.

The asymmetric unit of the title compound, C10H12N4OS, contains two independent mol­ecules, A and B, which differ significantly in the relative orientations of the benzene and triazole rings. The dihedral angle between the above two rings is 6.94 (5)° in mol­ecule A and 77.60 (5)° in mol­ecule B. In the crystal, mol­ecules are linked into a three-dimensional network by N—H⋯S, N—H⋯O, N—H⋯N and C—H⋯S hydrogen bonds and π–π inter­actions between the benzene and triazole rings [centroid–centroid distance = 3.5311 (6) Å] are also present.

The title mol­ecule, C7H7Cl2N3OS, is approximately planar [maximum deviation = 0.062 (1) Å]. Short inter­molecular distances between the centroids of the five-membered rings [3.5340 (8) Å] indicate the existence of π–π inter­actions. An inter­esting feature of the crystal structure is the presence of short intra­molecular Cl⋯N inter­actions [3.0015 (11) Å]. Mol­ecules are linked via pairs of inter­molecular N—H⋯O hydrogen bonds, generating R 2 2(8) ring motifs. Furthermore, N—H⋯O hydrogen bonds form R 2 1(7) ring motifs with C—H⋯O contacts, further consolidating the crystal structure. In the crystal, mol­ecules are linked by these inter­molecular inter­actions, forming chains along [001].

The title compound, C18H21N3O3, is a potential bidentate Schiff base ligand. The whole mol­ecule is disordered with a refined site-occupancy ratio of 0.567 (4):0.433 (4) and not just one ethyl group as reported previously [Sarojini et al. (2007 ▶). Acta Cryst. E63, o4782–o4782]. Using the whole mol­ecule disorder, R values are much smaller than those published. An intra­molecular O—H⋯N hydrogen bond generates a six-membered ring, producing an S(6) ring motif. The dihedral angle between the mean plane of the two benzene rings (major component) is 9.0 (5)°. The crystal structure shows short C⋯C [3.189 (15)–3.298 (12) Å] and C⋯O [2.983 (5)–3.149 (13) Å] contacts. Inter­molecular C—H⋯O inter­actions link neighbouring mol­ecules into dimers with R 2 2(18) motifs. In the crystal structure, these dimers are linked together by inter­molecular C—H⋯O inter­actions into one-dimensional extended chains along the b axis. The crystal structure is further stabilized by inter­molecular π–π stacking inter­actions [centroid–centroid distances = 3.458 (8)–3.691 (6) Å].