Crystal structure of 4-methyl­sulfanyl-2-phenyl­quinazoline

In the title compound, C₁₅H₁₂N₂S, the methylthioquinazoline group is planar with the methyl C displaced by only 0.116 (3) Å from the plane of the quinazoline moiety. The dihedral angle between the phenyl ring and the quinazoline ring system is 13.95 (5)°. In the crystal, each molecule is linked by π–π stacking between to two adjacent inversion-related molecules. On one side, the inverted quinazoline groups interact with a centroid–centroid distance of 3.7105 (9) Å. On the other side, the quinazoline group interacts with the pyrimidine and phenyl rings of the second neighbour with centroid–centroid distances of 3.5287 (8) and 3.8601 (9) Å, respectively.

Crystal structure of 2-ethyl­quinazoline-4(3H)-thione

In the title compound, C₁₀H₁₀N₂S, all non-H atoms are almost coplanar [maximum deviation = 0.103 (1) Å]. In the crystal, N—H...S inter­actions form R₂²(8) rings linking pairs of mol­ecules related by inversion. The mol­ecular pairs are stacked along [100]. A herringbone arrangement of pairs in the [010] direction forms layers parallel to (010).

Crystal structure of 4,4-dibutyl-2-phenyl-3,4-di­hydro­quinazoline

In the title compound, C₂₂H₂₈N₂, the dihedral angle between the planes of the phenyl ring and the di­hydro­quinazoline ring system (r.m.s. deviation = 0.030 Å) is 24.95 (7)° and both n-butane chains assume all-trans conformations. In the crystal, N—H...N hydrogen bonds link the mol­ecules into C(4) chains propagating in the [001] direction.

Crystal structure of 4-meth­oxy­quinazoline

The title compound, C₉H₈N₂O, is almost planar, with the C atom of the meth­oxy group deviating from the mean plane of the quinazoline ring system (r.m.s. deviation = 0.011 Å) by 0.068 (4) Å. In the crystal, mol­ecules form π–π stacks parallel to the b-axis direction [centroid–centroid separation = 3.5140 (18) Å], leading to a herringbone packing arrangement.