In the title compound, C12H9F3N2O2, the benzene ring is nearly perpendicular to the isoxazole ring, making a dihedral angle of 82.97 (2)°. In the crystal, mol­ecules are linked by N—H⋯O hydrogen bonds into a supra­molecular chain running along the c axis.

In the title compound, C16H24N2, the aliphatic amine substituent is rotated almost orthogonally [C—C—C—C torsion angle = 75.7 (3)°] out of the plane of the indole unit. The amine N atom has a pyramidal configuration deviating by 0.380 (3) Å from the plane of the adjacent C atoms. All of the aliphatic groups are in extended transoid conformations. In the crystal, mol­ecules form chains along the a axis via N—H⋯N hydrogen bonds.

In the racemic title compound, C14H17NO6, the plane of the ester group of the methyl hexa­noate side chain makes a dihedral angle of 80.0 (2)° with the benzene ring, while the nitro group is approximately coplanar with the benzene ring [dihedral angle = 10.3 (2)°]. In the crystal, mol­ecules form weak aromatic C—H⋯Onitro hydrogen-bonding inter­actions, giving inversion dimers [graph set R 2 2(8)].

In the title compound, C24H30N6O5, the cyclo­hexyl ring adopts a chair conformation, while the remainder of the mol­ecule adopts a U-shape. The dihedral angles between the pyridine ring and the pendant pyrimidine rings are 69.04 (12) and 75.99 (9)°. The two pyrimidine rings, however, are nearly parallel to one another, with a dihedral angle of 8.56 (15)° between them. They are also involved in an intra­molecular π–π stacking inter­action with a distance of 3.6627 (18) Å between the ring centroids. In the crystal, C—H⋯O contacts link the mol­ecules into chains along the b axis.

In the crystal structure of the title compound, C6H7NO2, the mol­ecules are are linked by inter­molecular O—H⋯N and O—H⋯O hydrogen bonds; π–π stacking is observed between parallel pyridine rings of adjacent mol­ecules [centroid-to-centroid distance = 3.7649 (12) Å].

In the title compound, C13H12N2O4, the dihedral angle between the benzene and pyrimidine rings is 55.57 (13)°. The carbonyl group and the two methoxyl groups are approximately coplanar with the benzene ring and pyrimidine ring; the C—C—C—O, C—O—C—N and C—O—C—C torsion angles being −6.1 (5), −4.8 (4) and 179.9 (3)°, respectively. In the crystal, mol­ecules are linked via C—H⋯O inter­actions, forming chains propagating along [110].

There are two independent mol­ecules in the asymmetric unit of the title compound, C15H10ClNO2, which differ in the dihedral angles between the mean planes of the phenyl ring and the 4-chloro­indoline-2,3-dione ring system [59.48 (9) and 79.0 (1)°]. In the crystal, mol­ecules are linked through C—H⋯O hydrogen bonds, forming polymeric chains in [100].

The title mol­ecule, C9H6ClNO2, is essentially planar: the maximum deviation from the mean plane of the indoline ring is 0.020 (2) Å and the substituents do not deviate by more than 0.053 (2) Å from this plane. C—H⋯O hydrogen bonds help to consolidate the crystal structure.

In the title compound, C15H10ClNO2,the dihedral angle between the mean planes of the benzene and 6-chloro­indoline-2,3-dione ring systems, linked through a methyl­ene group, is 81.68 (10)°. In the crystal, mol­ecules are connected by C—H⋯O hydrogen bonds, generating C(6) chains propagating in [010].

In the title compound, C11H8ClN3O4, the dihedral angle between benzene and isoxazole rings is 9.92 (1) °. The nitro group is almost coplanar with the benzene ring with an O—N—C—C torsion angle of 8.4 (3)°. The mol­ecular conformation is stabilized by an intra­molecular N—H⋯O hydrogen bond, closing a six-membered ring.

In the title compound, C9H7N5·H2O, the tetra­zole ring forms a dihedral angle of 1.82 (1)° with the mean plane of the indole fragment. In the crystal, mol­ecules are linked by inter­molecular O—H⋯N, N—H⋯O and N—H⋯N hydrogen bonds into a two-dimensional network parallel to (100). Addtional stabilization is provide by weak π–π inter­actions with a centroid–centroid distance of 3.698 (2) Å.

There are two mol­ecules with similar configurations in the asymmetric unit of the title compound, C9H7N5, which are linked by inter­molecular N—H⋯N hydrogen bonds into chains with graph-set motif C 2 2(8) along the b axis. The indole core has the expected planar geometry in the two mol­ecules, with a maximum deviation of 0.008 (8) Å from the least-squares plane defined by the nine constituent atoms, and the dihedral angles between the indole and tetra­zole rings are similar [42.4 (2) and 42.7 (2)°].

In the title compound, C6H10ClNO, an inter­mediate for the production of lysine, there are intra­molecular C—H⋯Cl hydrogen bonds.

In the crystal structure of the title compound, C13H14ClNO2, inter­molecular C—H⋯O inter­actions link the mol­ecules into a two-dimensional network.