Ethyl 2-methyl-6-(propan-2-yl-amino)-4-sulfanyl-idene-3H,11H-pyrimido[1,6-c]quinazoline-1-carboxyl-ate.

The title compound, C(18)H(22)N(4)O(2)S, contains a substituted pyrimidine ring fused to both a benzene ring and a substituted thioxopyrimidine ring. The pyrimidine and thioxopyrimidine rings adopt distorted chair conformations. In the crystal, adjacent mol-ecules are linked by pairs of N-H⋯S and N-H⋯O hydrogen bonds to generate centrosymmetric R(2) (2)(8) and R(2) (2)(16) loops, respectively. This combination leads to [100] chains of mol-ecules.

3,3'-(1,4-Phenyl-ene)bis-[2-(propyl-amino)-benzofuro[3,2-d]pyrimidin-4(3H)-one] ethanol disolvate.

The title compound, C(32)H(28)N(6)O(4)·2C(2)H(5)OH, consists of two 2-(propyl-amino)-benzofuro[3,2-d]pyrimidin-4(3H)-one units connected, via one of the pyrimidine N atoms, to a bridging benzene ring in the 1,4 positions. Two ethanol solvent mol-ecules are also present. The main mol-ecule lies on a center of symmetry located at the center of the benzene ring. The fused-ring system of the benzofuro[3,2-d]pyrimidine moiety is nearly planar (r.m.s. deviation = 0.016 Å) and forms a dihedral angle of 78.21 (7)° with the central benzene ring. The crystal structure features O-H⋯O and N-H⋯O inter-actions. The C atoms of the propyl-amino side chain in the main mol-ecule and the ethyl group in the solvent mol-ecule are disordered over two positions, with site-occupancy factors 0.34:0.66 and 0.42:0.58, respectively.

3-Isopropyl-2-p-tol-yloxy-5,6,7,8-tetra-hydro-1-benzothieno[2,3-d]pyrimidin-4(3H)-one.

In the title compound, C(20)H(22)N(2)O(2)S, the central thieno-pyrimidine ring system is essentially planar, with a maximum displacement of 0.023 (2) Å. The attached cyclo-hexene ring is disordered over two possible conformations, with an occupancy ratio of 0.776 (12):0.224 (12). Neither inter-molecular hydrogen-bonding inter-actions nor π-π stacking inter-actions are present in the crystal structure. The mol-ecular conformation and crystal packing are stabilized by three intra-molecular C-H⋯O hydrogen bonds and two C-H⋯π inter-actions.

Ethyl 1-(6-chloro-3-pyridylmeth-yl)-5-methyl-1H-1,2,3-triazole-4-carboxyl-ate.

In the title compound, C(12)H(13)ClN(4)O(2), the triazole ring carries methyl and ethoxy-carbonyl groups, and is bound via a methyl-ene bridge to a chloro-pyridine unit. There is evidence for significant electron delocalization in the triazolyl system. Intra-molecular C-H⋯O and inter-molecular C-H⋯N hydrogen bonds stabilize the structure.

3-Phenyl-2-(prop-2-yn-yloxy)-1-benzofuro[3,2-d]pyrimidin-4(3H)-one.

In the title compound, C(19)H(12)N(2)O(3), the 1-benzofuro[3,2-d]pyrimidinone unit is approximately planar, the maximum deviation from the mean plane being 0.045 (1) Å. The attached phenyl ring makes a dihedral angle of 86.73 (6)° with the fused ring system. The packing of the mol-ecules in the crystal structure is mainly governed by C-H⋯π hydrogen-bonding inter-actions.