The title compound, C(19)H(19)N(3)O(4)S(2), was prepared by the reaction of 2,3-diamino-pyridine with tosyl chloride in a mixture of dichloro-methane-pyridine as solvent. In the crystal, mol-ecules associate via pairs of N-H⋯N hydrogen bonds, forming a centrosymmetric eight-membered {⋯HNCN}(2) synthon. The dihedral angles between the amino-pyridine ring and the tosyl benzene rings are 50.01 (6)...

The title compound, C(19)H(9)N(5)O(4), has crystallographically imposed twofold rotational symmetry. The asymmetric unit contains one half-mol-ecule. The crystal structure is stabilized by π-π stacking of inversion-related pyrrolo-[3,4-b]pyridine rings, with a centroid-centroid distance between stacked pyridines of 3.6960 (8) Å. The dihedral angle between the central pyridine ring and the pyrro...

In the title compound, C(12)H(9)FN(2)O, the dihedral angle between the benzene ring and the pyridine ring is 4.35 (16)°. The mol-ecular conformation is stabilized by an intra-molecular O-H⋯N hydrogen bond.

In the title compound, C(22)H(21)N, the pyridine ring adopts a distorted boat conformation, while the adjacent pyran ring adopts a chair conformation; the heterocyclic rings make a dihedral angle of 40.1 (2)° with each other.

Pyridoxal 5'-phosphate (PLP; vitamin B(6))-catalyzed reactions have been well studied, both on enzymes and in solution, due to the variety of important reactions this cofactor catalyzes in nitrogen metabolism. Three functional groups are central to PLP catalysis: the C4' aldehyde, the O3' phenol, and the N1 pyridine nitrogen. In the literature, the pyridine nitrogen has traditionally been assum...

In the title compound, C19H19N5, the piperidine ring adopts a chair conformation. The pyridine ring is essentially planar, with a maximum deviation of 0.039 (2) Å for a C atom substituted with a carbonitrile group. The mean plane of the central pyridine ring makes the dihedral angles of 37.90 (14) and 56.10 (12)° with the piperidine and benzene rings, respectively. In the crystal, mol-ecules ar...

The mol-ecules of the two isotypic title compounds, C25H24BrN3, (I), and C25H24FN3, (II), comprise a 2-imino-pyridine ring fused with a cyclo-octane ring. In (I), the cyclo-octane ring adopts a twisted chair-chair conformation, while in (II), this ring adopts a twisted boat-chair conformation. The dihedral angles between the planes of the pyridine ring and the bromo-benzene and phenyl rings are...

The title compound, C(20)H(17)N(3)O(2)·CH(4)O·H(2)O, was synthesized by the condensation reaction of 2-benzyl-oxybenzaldehyde with isoniazid (isonicotinic acid hydrazide). The tricyclic compound displays a trans configuration with respect to the C=N double bond. The central benzene ring makes dihedral angles of 8.83 (7) and 70.39 (8)° with the pyridine ring and the terminal benzene ring, respec...

The title compound, C(18)H(16)N(4)O, is built up from fused six- and five-membered rings linked to a five-membered isoxazole ring and to a six-membered pyridine ring through a CH(2) group. The fused-ring system is essentially planar, with a maximum deviation of 0.019 (1) Å. It forms inter-planar angles of 70.03 (7)° with the isoxazole ring and 81.68 (7)° with the pyridine ring; the two latter r...

In the title compound, C(24)H(17)N(2)O(4) (+)·NO(3) (-)·0.25H(2)O, the central pyridine ring of the 2',6'-bis-(4-carb-oxy-phen-yl)-4,4'-bipyridin-1-ium cation is almost coplanar with one benzene ring [dihedral angle = 1.03 (5)°], while it makes dihedral angles of 9.59 (5)° with the other benzene ring and 13.66 (6)° with the pyridinium ring. In the crystal, N-H⋯O and O-H⋯O hydrogen bonds link th...