There are two independent mol­ecules in the asymmetric unit of the title compound, C21H18BrFO3, in which the dihedral angles between the fluoro­phenyl and bromo­phenyl groups are 77.0 (1) and 85.8 (1)°. In one of the mol­ecules, two methine C—H groups of the cyclo­hexene ring are disordered over two sets of sites in a 0.53 (2):0.47 (2) ratio. In both mol­ecules, the atoms of the ethyl group were refined as disordered over two sets of sites with occupancies of 0.67 (2):0.33 (2) and 0.63 (4):0.37 (4). The cyclo­hexene rings have slightly distorted sofa conformations in both mol­ecules. In the crystal, C—H⋯O inter­actions link mol­ecules into chains along the b axis.

In the title compound, C21H16BrFN2, the fluoro-substituted benzene ring is disordered over two orientations about the C—F bond and the C—C bond between the benzene and pyrazole groups with a site-occupancy ratio of 0.516 (8):0.484 (8). The central pyrazole ring [maximum deviation = 0.035 (3) Å] makes dihedral angles of 22.4 (2), 11.0 (2), 77.19 (16) and 7.44 (17)° with the two disorder components of the benzene ring, the bromo-substituted benzene ring and the phenyl ring, respectively. In the crystal, mol­ecules are linked into a layer parallel to the bc plane through C—H⋯π inter­actions.

In the title compound, C19H18BrFN2O, the benzene rings form dihedral angles of 5.38 (7) and 85.48 (7)° with the mean plane of the 4,5-dihydro-1H-pyrazole ring (r.m.s. deviation = 0.0849 Å), which approximates to an envelope conformation with the –CH2– group as the flap. The dihedral angle between the benzene rings is 82.86 (7)°. In the crystal, C—H⋯F and C—H⋯O hydrogen bonds link the mol­ecules to form inversion dimers and together these generate chains along [011]. The crystal packing also features C—H⋯π inter­actions.

In the title compound, C17H15FN2O, the pyrazoline ring adopts a flattened envelope conformation. The dihedral angle between the fluoro-substituted benzene ring and the phenyl ring is 69.20 (5)°. In the crystal, a pair of C—H⋯O hydrogen bonds link neighbouring mol­ecules, forming an inversion dimer. The crystal structure is further consolidated by C—H⋯π inter­actions and by a π–π inter­action with a centroid–centroid distance of 3.7379 (6) Å.

In the title mol­ecule, C17H14BrFN2O, the benzene rings form dihedral angles of 6.58 (6) and 85.31 (6)° with the mean plane of the 4,5-dihydro-1H-pyrazole ring (r.m.s. deviation = 0.0231 Å). The latter ring is planar with a maximum deviation of 0.032 (1) Å The dihedral angle between the benzene rings is 78.75 (6)°. In the crystal, weak C—H⋯O and C—H⋯F hydrogen bonds link the mol­ecules into corrugated layers parallel to the ab plane.

In the title mol­ecule, C21H14BrFN4O4, the mean planes of the two nitro groups form dihedral angles of 3.1 (2) and 7.1 (5)° with the benzene ring to which they are attached. The dinitro-substituted ring forms dihedral angles of 8.6 (2) and 71.9 (2)° with the bromo- and fluoro-substituted benzene rings, respectively. The dihedral angle between the bromo- and fluoro-substituted benzene rings is 80.6 (2)°. There is an intra­molecular N—H⋯O hydrogen bond. In the crystal, pairs of weak C—H⋯O hydrogen bonds form inversion dimers. In addition, π–π stacking inter­actions between the bromo- and dinitro-substituted rings [centroid–centroid separation = 3.768 (2) Å] are observed.

In the title compound, C18H16Cl2O4, the dihedral angle between the benzene rings is 82.40 (4)°. The meth­oxy groups at both meta positions of the 3,4,5-trimeth­oxy­phenyl ring are slightly twisted from the aromatic ring [C—O—C—C = −166.60 (8) and −6.18 (13)°], whereas the meth­oxy group at the para position is almost perpendicular [C—O—C—C = 112.08 (9)°]. The ketone O atom is connected to the 2,4-dichloro­phenyl group through a Car—Car—C—O (ar = aromatic) torsion angle of −116.43 (9)°. In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds into infinite chains along the b axis. The crystal structure also features C—H⋯π inter­actions.

In the title compound, C15H10ClFO, the fluoro-substituted benzene ring forms a dihedral angle of 44.41 (6)° with the chloro-substituted benzene ring. The only significant directional bonds in the crystal are weak C—H⋯π inter­actions.