In the title compound, C(20)H(14)FN(3)O, the quinoxaline system makes dihedral angles of 32.38 (7) and 48.04 (7)° with the 4-fluoro-phenyl and pyridine rings, respectively. The 4-fluoro-phenyl ring makes a dihedral angle of 57.77 (9)° with the pyridine ring. In the crystal, the mol-ecules form dimeric C-H⋯N hydrogen-bonded R(2) (2)(20) ring motifs lying about crystallographic inversion centers....

In the title compound, C(14)H(9)FN(2)O(2)S, the thieno[2,3-b]pyridine residue is almost planar (r.m.s. deviation = 0.0194 Å), with the carb-oxy-lic acid group [dihedral angle = 11.9 (3)°] and the benzene ring [71.1 (4)°] being twisted out of this plane to different extents. An intra-molecular N-H⋯O(carbon-yl) hydrogen bond closes an S(6) ring. Supra-molecular chains along [01-1] mediated by O-H...

In the title compound, C(29)H(29)N(5), the central pyridine ring and the two pyrazole rings are approximately coplanar, the dihedral angles between the pyridine and pyrazole rings being 3.94 (12) and 14.84 (12)°. The pyrazole and phenyl rings on each side of the mol-ecule are twisted with dihedral angles of 46.72 (8) and 73.39 (8)°. One phenyl ring inter-acts with a pyrazole ring of a neighbour...

In the title compound, C(28)H(26)N(4)O(4), the tetra-hydro-pyridine ring adopts a boat conformation. The two phenyl rings form dihedral angles of 88.64 (8) and 59.28 (10)° with the best plane through the tetra-hydro-pyridine ring. The dihedral angle between the two phenyl rings is 82.55 (10)°. The benzotriazole ring system is essentially planar, with a maximum deviation of 0.009 (1) Å from the ...

In the crystal structure of the title compound, C(22)H(17)N(3)O, the oxazine ring has a half-chair conformation. The dihedral angles between the best least-squares plane through the pyridine rings and the planar part (O-C-C-C-N) of the oxazine ring are 72.14 (6) and 35.44 (7)°, the smaller angle involving the pyridine ring adjacent to the oxazine O atom. The mol-ecule has two stereogenic center...

In the title compound, C(13)H(16)ClN(5)O(4), the imidazole ring is in a slight envelope conformation. The dihedral angle between the pyridine ring and the four essentially planar atoms [maximum deviation 0.015 (2) Å] of the imidazole ring is 80.8 (1)°. In, the crystal, weak C-H⋯O and C-H⋯N hydrogen bonds are present. In addition, there are weak π-π stacking inter-actions between symmetry-relate...

In the title mol-ecule, C(21)H(19)N(3)O(2), the central pyridine ring makes dihedral angles of 14.46 (9) and 34.67 (8)° with the 4-amino- and 4-eth-oxy-substituted benzene rings, respectively. The eth-oxy group is essentially coplanar with the attached benzene ring [C-O-C-C torsion angle = 178.70 (16)°] as is the meth-oxy group with the pyridine ring [C-O-C-N torsion angle = -3.0 (3)°]. In the ...

In the title compound, C(19)H(23)NO(6), the 1,4-dihydro-pyridine ring is twisted slightly from planarity, with a maximum deviation of 0.101 (1) Å, and adopts a very flattened boat conformation. The dihedral angle formed between the plane through the four C atoms of the 1,4-dihydro-pyridine ring and the benzene ring is 84.67 (7)°. In the crystal structure, inter-molecular N-H⋯O and C-H⋯O hydroge...

The title compound, C30H29NO4, is a tetra-cyclic system containing a 4-aryl-pyridine fragment, two benzene rings and an aza-17-crown-5 ether moiety, in a bowl-like arrangement. The pyridine ring is inclined to the 4-methyl-phenyl ring by 26.64 (6)°, and by 57.43 (6) and 56.81 (6)° to the benzene rings. The benzene rings are inclined to one another by 88.32 (6)°. In the crystal, mol-ecules are l...

In the title compound, C(16)H(14)ClN(3)O(2), the 2,3-dihydro-1,3,4-oxadiazole ring [maximum deviation = 0.030 (1) Å] and the pyridine ring [maximum deviation = 0.012 (1) Å] are inclined slightly to one another, making a dihedral angle of 11.91 (5)°. The chloro-substituted phenyl ring is almost perpendicular to the 2,3-dihydro-1,3,4-oxadiazole and pyridine rings at dihedral angles of 86.86 (5) a...