N-(2,5-Dimeth­oxy­phen­yl)-6-nitro­quinazolin-4-amine

In the title mol­ecule, C₁₆H₁₄N₄O₄, the quinazoline ring is substanti­ally planar (r.m.s. deviation = 0.0129 Å) and forms a dihedral angle of 2.73 (8)° with the benzene ring. The conformation of the mol­ecule is stabilized by an intra­molecular C—H...N hydrogen bond. In the crystal, mol­ecules are linked into chains running parallel to the b axis by C—H...O hydrogen bonds. In addition, π–π stacking is observed between dimethoxy-substituted and nitro-substituted benzene rings, with centroid–centroid distances in the range 3.6438 (10)–3.7148 (10) Å.

2-{[(Dimethyl­amino)­methyl­idene]amino}-5-nitro­benzonitrile

The title mol­ecule, C₁₀H₁₀N₄O₂, is almost planar and adopts an E configuration of the azomethine [C=N = 1.298 (2) Å] double bond. The benzene ring is attached to an essentially planar (r.m.s. deviation = 0.0226 Å) amidine moiety (N=CN/Me₂), the dihedral angle between the two mean planes being 18.42 (11)°. The cyano group lies in the plane of the benzene ring [the C and N atoms deviating by 0.030 (3) and 0.040 (3) Å, respectively], while the nitro group makes a dihedral angle 5.8 (3)° with the benzene ring. There are two distinct inter­molecular hydrogen bonds, C—H...O and C—H...N, that stabilize the crystal structure; the former inter­actions result in centrosymmetric dimers about inversion centers resulting in ten-membered rings, while the later give rise to chains of mol­ecules running parallel to the b axis.

5-Chloro-2-(4-meth­oxy­phen­yl)-1,3-benzo­thia­zole

In the title compound, C₁₄H₁₀ClNOS, the dihedral angle between the benzothia­zole ring system and the meth­oxy-substituted benzene ring is 8.76 (16)°. In the crystal, mol­ecules are stacked in columns along the c axis and no significant inter­molecular inter­actions are observed.

(E)-2,4-Dimethyl-N′-(2-methyl­benzyl­idene)benzohydrazide

In the title benzoyl­hydrazide derivative, C₁₇H₁₈N₂O, the dihedral angle between the benzene rings is 88.45 (8)° and the azomethine double bond adopts an E conformation. In the crystal, mol­ecules are linked by N—H...O and C—H...O hydrogen bonds, forming a chain along the b axis.

1-(2-Methyl-5-nitro-1H-imidazol-1-yl)acetone

In the mol­ecule of the title compound, C₇H₉N₃O₃, the nitro and carbonyl groups are tilted with respect to the imidazole ring by 9.16 (6) and 65.47 (7)°, respectively. Neighbouring chains are linked via C—H...N and C—H...O hydrogen bonds forming two-dimensional slab-like networks lying parallel to (01-1).