2-Eth­oxy-5-methylbis[1,2,4]triazolo[1,5-a:4′,3′-c]quinazoline

The title compound, C₁₃H₁₂N₆O, is a functionalized ditriazoloquinazoline with substituted eth­oxy and methyl groups attached at the 2-position of each triazole spacer. The fused-ring system is essentially planar [r.m.s. deviation = 0.016 (2) Å]. In the crystal, a weak C—H...N hydrogen bond connects the mol­ecules into a chain along [101].

3-Benzyl-6-methyl-2-sulfanylidene-2,3-di­hydroquinazolin-4(1H)-one

In the title compound, C₁₆H₁₄N₂OS, the quinazoline ring system is essentially planar, with a maximum deviation of 0.029 (3) Å. The dihedral angle between the quinazoline and benzene rings is 88.4 (2)°. In the crystal, adjacent mol­ecules are connected via pairs of N—H...S and C—H...O hydrogen bonds, which generate R²₂(8) and R²₂(10) graph-set motifs, respectively, resulting in a supra­molecular chain along the a axis.

2-Methyl­sulfanyl-1,2,4-triazolo[1,5-a]quinazolin-5(4H)-one

The non-H atoms of the title compound, C₁₀H₈N₄OS, lie approximately in a common plane (r.m.s. deviation = 0.058 Å). In the crystal, two mol­ecules are linked across a center of inversion by a pair of N—H...N hydrogen bonds, forming a a dimer.

2-Methyl­sulfonyl-1,2,4-triazolo[1,5-a]quinazolin-5(4H)-one

The triazoloquinazoline fused-ring system of the title compound, C₁₀H₈N₄O₃S, is essentially planar (r.m.s. deviation = 0.027 Å). In the crystal, adjacent mol­ecules are linked by N—H...O_sulfon­yl hydrogen bonds, generating a helical chain running along the b axis.

3-Benzyl-8-meth­oxy-2-sulfanyl­idene-1,2,3,4-tetra­hydro­quinazolin-4-one

The tetra­hydro­quinazole fused-ring system of the title compound, C₁₆H₁₄N₂O₂S, is roughly planar (r.m.s. deviation = 0.039 Å); the phenyl ring of the benzyl substituent is aligned at 78.1 (1)° with respect to the mean plane of the fused-ring system. In the crystal, two mol­ecules are linked by a pair of N—H...S hydrogen bonds about a center of inversion, generating a dimer.

2-Phen­oxy-1,2,4-triazolo[1,5-a]quinazol­in-5(4H)-one

The triazoloquinazole ring system in the title compound, C₁₅H₁₀N₄O₂ is approximately planar (r.m.s. deviation = 0.035 Å). The phenyl ring of the phen­oxy substitutent is aligned at 59.3 (1)° with respect to this ring system. In the crystal, two mol­ecules are linked about a center of inversion by a pair of N—H...O hydrogen bonds, generating a dimer.

5-Chloro-2-methyl­sulfonyl-1,2,4-triazolo[1,5-a]quinazoline

The triazoloquinazole fused-ring system of the title compound, C₁₀H₇ClN₄O₂S, is essentially planar (r.m.s. deviation = 0.009 Å). In the methyl­sulfonyl substituent, the two S—O bonds are of equal length [1.402 (2) Å]. In the crystal, adjacent mol­ecules inter­act weakly through Cl...N contacts [ca 3.197 (2) Å].

3-(Prop-2-en-1-yl)-2-sulfanyl­idene-1,2,3,4-tetra­hydro­quinazolin-4-one

The tetra­hydro­quinazoline fused-ring system of the title compound, C₁₁H₁₀N₂OS, is approximately planar (r.m.s. deviation = 0.019 Å). In the crystal, adjacent mol­ecules are linked by N—H...O hydrogen bonds, forming a chain running along the b axis.

N-[2,4-Dioxo-3-aza­tricyclo­[7.3.1.0^5,13]trideca-1(13),5,7,9,11-pentaen-3-yl]thio­urea

In the two independent mol­ecules in the asymmetric unit of the title compound, C₁₃H₉N₃O₂S, the aza­tricyclo­trideca­penta­ene ring system is approximately planar with r.m.s. deviations of 0.022 and 0.033 Å. The urea unit connected to the fused rings is approximately perpendicular [dihedral angles = 82.4 (1) and 82.7 (1)°]. In the crystal, the mol­ecules associate by N—H...O hydrogen bonds, forming a chain running along the a axis. The crystal studied was a non-merohedral twin with a fractional contribution of 49.6 (1)% for the minor domain.