N-(6-Meth-oxy-pyridin-2-yl)-1-(pyridin-2-ylmeth-yl)-1H-pyrazole-3-carboxamide: crystal structure and Hirshfeld surface analysis.

The title compound, C16H15N5O2, adopts the shape of the letter L with the dihedral angle between the outer pyridyl rings being 78.37 (5)°; the dihedral angles between the central pyrazolyl ring (r.m.s. deviation = 0.0023 Å) and the methyl-ene-bound pyridyl and methyoxypyridyl rings are 77.68 (5) and 7.84 (10)°, respectively. Intra-molecular amide-N-H⋯N(pyrazol-yl) and pyridyl-C-H⋯O(amide) inter-actions are evident and these preclude the participation of the amide-N-H and O atoms in inter-molecular inter-actions. The most notable feature of the mol-ecular packing is the formation of linear supra-molecular chains aligned along the b-axis direction mediated by weak carbonyl-C=O⋯π(triazol-yl) inter-actions. An analysis of the calculated Hirshfeld surfaces point to the importance of H⋯H (46.4%), C⋯H (22.4%), O⋯H (11.9%) and N⋯H (11.1%) contacts in the crystal.

7-(4-Bromo-phen-yl)-9-phenyl-7H-pyrrolo[3,2-e]tetra-zolo[1,5-c]pyrimidine.

In the title compound, C(18)H(11)BrN(6), the phenyl ring is almost coplanar [dihedral angle 7.2 (1)°] with the planar (r.m.s. deviation 0.039 Å) tricyclic ring system while the 4-bromo-phenyl ring makes a dihedral angle of 33.98 (6)° with the ring system. Weak inter-molecular C-H⋯N and C-H⋯Br hydrogen-bonding inter-actions and π-π stacking [centroid-centroid distances = 3.7971 (17) and 3.5599 (16) Å] stabilize the crystal packing. A comparison of the structure to a MOPAC PM3 geometry optimization calculation in vacuo supports these observations.

7-(4-Chloro-phen-yl)-9-phenyl-7H-pyrrolo[3,2-e]tetra-zolo[1,5-c]pyrimidine.

In the title compound, C(18)H(11)ClN(6), the pyrrole, pyrimidine and tetra-zole rings form a nearly planar fused trihetrocyclic system with an r.m.s. deviation of 0.0387 (13) Å, to which the 4-chloro-phenyl group and the phenyl group are substituted at the 7 and 9 positions, respectively. The dihedral angles between the pyrrole ring and the 4-chloro-phenyl and phenyl rings are 32.1 (4) and 7.87 (7)°, respectively. In the crystal, weak inter-molecular C-H⋯N and C-H⋯Cl hydrogen bonds link the mol-ecules into a layer parallel to the (001) plane. The layers are further connected by π-π stacking inter-actions [centroid-centroid distances: 3.8413 (8) and 3.5352 (8) Å]. Intra-molecular C-H⋯N hydrogen bonds are also present.

12-(4-Methoxy-phen-yl)-10-phenyl-3,4,5,6,8,10-hexa-azatricyclo-[7.3.0.0]dodeca-1(9),2,4,7,11-penta-ene.

In the title compound, C(19)H(14)N(6)O, the fused 12-membered tetra-zolo/pyrimidine/pyrrole ring system is almost planar (r.m.s. deviation = 0.013 Å). The 4-methoxy-phenyl and phenyl substituents on the pyrrole ring are both twisted with respect to the fused-ring system [dihedral angles = 25.39 (18) and 36.42 (18)°, respectively]. Intra-molecular C-H⋯N inter-actions occur. In the crystal, mol-ecules pack into layers in the ac plane and these are connected along the b axis via C-H⋯π and π-π [centroid-centroid separation = 3.608 (3) Å] inter-actions.

12-(4-Chloro-phen-yl)-7-methyl-10-phenyl-3,4,5,6,8,10-hexa-aza-tricyclo-[7.3.0.0]dodeca-1(9),2,4,7,11-penta-ene.

The 12 non-H atoms defining the triple-fused-ring system in the title compound, C(19)H(13)ClN(6), are almost coplanar (r.m.s. deviation = 0.023 Å). The chloro-substituted ring is almost effectively coplanar with the central atoms [dihedral angle = 6.74 (13)°], but the N-bound benzene ring is not [dihedral angle = 54.38 (13)°]. In the crystal, supra-molecular chains along the a axis sustained by C-H⋯π and π-π [centroid-centroid distance between N(4)C and C(4)N five-membered rings = 3.484 (2) Å] stacking occur. A very long C-Cl⋯π contact is also seen.

7-(4-Methoxy-phen-yl)-5-methyl-9-phenyl-7H-pyrrolo[2',3':4,5]pyrimido[1,6-d]tetrazole.

The title compound, C(20)H(16)N(6)O, is composed of a tetra-zolo ring and a 4-methoxy-phenyl and a benzene-substituted pyrrole ring at the 7 and 9 positions fused to a pyrimidine ring in a nearly planar fashion [maximum deviation of 0.018 (1) Šfor the fused ring system]. A methyl group at the 5 position is also in the plane of the hetero cyclic system. The dihedral angle between the mean planes of the benzene and 4-methoxy-phenyl rings is 40.4 (2)°. The dihedral angles between the mean planes of the pyrimidine and the benzene and 4-methoxy-phenyl rings are 15.6 (5)° and 52.6 (7)°, respectively. A weak intra-molecular C-H⋯N hydrogen bond inter-action, which forms an S(7) graph-set motif, helps to establish the relative conformations of the tetrazolo and benzene rings. In the crystal, weak inter-molecular C-H⋯O, C-H⋯π and π-π stacking inter-actions [centroid-centroid distances = 3.5270 (16), 3.5113 (16), 3.7275 (17) and 3.7866 (17) Å] link the mol-ecules into a two-dimensional array obliquely parallel to (101) and propagating along the b axis.