N′-(1-Allyl-2-oxoindolin-3-yl­idene)benzohydrazide

In the title compound, C18H15N3O2, the dihedral angle between the ring systems is 15.1 (1)°. The amino H atom is hydrogen bonded to the exocyclic O atom of the five-membered ring, forming an S(6) motif

5-(Pyridin-4-ylmeth­yl)-1H-pyrazolo­[3,4-d]pyrimidin-4(5H)-one

In the title compound, C11H9N5O, the pyrazolo­pyrimidin-4-one ring system is almost planar, with a maximum deviation of 0.0546 (13) Å for the O atom. The crystal packing is stabilized by inter­molecular N—H⋯N, C—H⋯O and C—H⋯N hydrogen bonds. In addition, π–π stacking is found between the pyridine ring and the pyrazolo­pyrimidin-4-one ring systems, with centroid–centroid distances in the range 3.9627 (12)–4.6781 (12) Å

5,6,7,8-Tetrahydro-[1,2,4]triazolo[5,1-b]quinazolin-9(4H)-one

The triazole ring in the title molecule, C9H10N4O, is not quite coplanar with the six-membered ring to which it is fused, the dihedral angle between the two least-squares planes being 2.52 (6)°. In the crystal, a layered structure is formed by N—H...N and C—H...O hydrogen bonds plus slipped π-stacking interactions, with the fused cyclohexene rings projecting to either side

Synthesis, crystal structure and Hirshfeld surface analysis of 1-[3-(2-oxo-3-phenyl-1,2-dihydroquinoxalin-1-yl)propyl]-3-phenyl-1,2-dihydroquinoxalin-2-one

In the title compound, C31H24N4O2, the dihydroquinoxaline units are both essentially planar with the dihedral angle between their mean planes being 64.82 (4)°. The attached phenyl rings differ significantly in their rotational orientations with respect to the dihydroquinoxaline planes. In the crystal, one set of C—H...O hydrogen bonds form chains along the b-axis direction, which are connected in pairs by a second set of C—H...O hydrogen bonds. Two sets of π-stacking interactions and C—H...π(ring) interactions join the double chains into the final three-dimensional structure

2-[4-(2-Chlorobenzyl)-3-methyl-6-oxo-1,6-dihydropyridazin-1-yl]-N-(4-fluorophenyl)acetamide

The conformation of the title molecule, C20H17ClFN3O2, is partly determined by an intramolecular C—H...O hydrogen bond, which leads to a dihedral angle of 14.7 (4)° between the fluorobenzene ring and the acetamide group. The 2-chlorobenzyl group is rotationally disordered over two orientations in a 0.656 (2): 0.344 (2) ratio. In the crystal, a layered structure is formed by N—H...O, C—H...O and C—H...F hydrogen bonds plus slipped π–π stacking interactions