6,7,8,9,10,11-Hexahydro-13H-azocino[2,1-b]quinazolin-13-one

The title compound, C14H16N2O, is a synthetic analogue of quinazolone alkaloids with pyrrilo, pyrido and azopino rings. The quinazolinic part of the mol­ecule is generally planar within 0.037 (3) Å; the eight-membered ring exhibits an inter­mediate conformation between the chair and boat forms as it is typical for cyclo­octene rings. An ethyl­ene group of the azopino ring is disordered over two positions with a refined occupancy ratio of 0.910 (7):0.090 (7). In the crystal, the H atoms of the aromatic rings form weak C—H⋯O and C—H⋯N hydrogen bonds. One C—H⋯O hydrogen bond leads to the formation of a one-dimensional chain. Another C—H⋯O and a C—H⋯N bond link these chains, generating a three-dimensional network

(E)-3-Propoxymethyl­idene-2,3-dihydro-1H-pyrrolo[2,1-b]quinazolin-9-one monohydrate

The title compound, C15H16N2O2·H2O, was synthesized via the alkyl­ation of 3-hydroxy­methyl­idene-2,3-dihydro-1H-pyrrolo[2,1-b]quinazolin-9-one with n-propyl iodide in the presence of sodium hydroxide. The organic mol­ecule and the water mol­ecule both lie on a crystallographic mirror plane. In the crystal structure, inter­molecular O—H⋯O and O—H⋯N hydrogen bonds link the components into extended chains along [100]

3-Benzyl-6-(2-chloro­benzo­yl)-1,3-benzoxazol-2(3H)-one

In the title compound, C21H14ClNO3, the benzoxazolone ring system is planar (r.m.s. deviation = 0.022 Å) and forms dihedral angles of 75.38 (10) and 65.92 (13)° with the mean planes of the chloro­benzoyl (r.m.s. deviation = 0.045 Å, excluding O atom) and benzyl (r.m.s. deviation = 0.023 Å) groups. The observed structure is stabilized by weak C—H⋯O hydrogen bonds and weak inter­molecular C—H⋯π inter­actions

1,3-Dibenzyl-1,2,3,4-tetrahydroquinazoline-2,4-dione

The asymmetric unit of the title compound, C22H18N2O2, contains two independent molecules, which differ in the orientations of the benzyl groups with respect to the planar (r.m.s. deviations of 0.031 and 0.020 Å) quinazoline-2,4-dione skeletons [dihedral angles of 73.97 (4) and 70.07 (4)° in the first molecule and 75.63 (4) and 63.52 (3)° in the second]. The crystal structure is stabilized by weak intermolecular C—H...O and C—H...π interactions and aromatic π–π stacking interactions [centroid–centroid distance = 3.735 (2) Å]