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The 1,2,4-triazolo[1,5-a][1,3,5]triazine system in the title compound, C(17)H(14)FN(7)·2CH(3)OH, is essentially planar, with an r.m.s. deviation of 0.0215 Å. The attached phenyl ring lies almost in the mean plane of the heterocyclic core [dihedral angle = 3.56 (4)°]. In the crystal, centrosymmetric inversion dimers connected via inter-molecular N-H⋯N hydrogen bonds between H atom of the primary amino group and the triazine N atom [R(2) (2)(8) graph-set motif] form sheets parallel to (010). A second set of dimers connected via N-H⋯F hydrogen bonds between the other H atom of the primary amino group and the F atom forms an R(2) (2)(24) graph-set motif linking the sheets. Methanol solvent mol-ecules are packed in channels running along the [010] direction.

In the title compound, C(10)H(12)N(6)·C(2)H(5)OH, the planarity of the heterocyclic system is slightly distorted at the triazine ring (r.m.s. deviation = 0.1191 Å), which adopts a conformation best described as inter-mediate between a flattened twisted boat and a half-boat with the tertiary Csp(3) atom at the bow. In the crystal, mol-ecules form centrosymmetric dimers connected by N⋯H-O and O⋯H-N hydrogen bonds between the amino group H atom, the ethanol solvent mol-ecule and the triazine N atom, making an R(4) (4)(12) graph-set motif. The other H atom of the amino group and the H atom on the endocyclic N atom form N⋯H-N hydrogen bonds with the N atoms of the pyrazole and pyridine rings, respectively, linking the mol-ecules into C(7)C(7) chains with the R(2) (2)(8) binary graph-set motif running along [010].

In the title compound, C(16)H(13)N(7)O, the 1,2,4-triazolo[1,5-a][1,3,5]triazine heterocyclic system is essentially planar (r.m.s. deviation = 0.0375 Å). The attached benzene ring lies almost in the mean plane of 1,2,4-triazolo[1,5-a][1,3,5]triazine [dihedral angle = 1.36 (23)°], while the pyridine ring is turned out of this plane by the amino-methyl bridge [dihedral angle = 69.22 (9)°]. The amino group H atom is involved in intra-molecular hydrogen bonding with a triazole N atom. In the crystal, mol-ecules are connected via C(=O)NH⋯N hydrogen bonds into C(11) chains parallel to [100]. The amino group H atom acts as a hydrogen-bond donor, forming an NH⋯O=C hydrogen bond with the carbonyl O atom, which links the mol-ecules into C(6) chains running along [011] and [01].

The title compound, C(12)H(13)N(5)O(2)S {systematic name: ethyl N-[N-(3-phenyl-1H-1,2,4-triazol-5-yl)carbamothio-yl]carbamate}, is a monoclinic polymorph (space group P2(1)/c) which crystallizes with three similar independent mol-ecules in the asymmetric unit. The triazole ring makes dihedral angles of 6.6 (2), 8.4 (2) and 10.6 (2)° with the phenyl ring in the three independent molecules. The structure was previously reported [Dolzhenko et al. (2010a ▶). Acta Cryst., E46, o425] as a triclinic polymorph crystallizing in space group P. Mol-ecules in both polymorphs possess two S(6) rings generated by intra-molecular N-H⋯S and N-H⋯O hydrogen bonds, resulting in similar mol-ecular geometries. However, the two polymorphs differ in the crystal packing. In contrast to the dimers of the triclinic polymorph, mol-ecules of the monoclinic polymorph are connected by inter-molecular N-H⋯S and N-H⋯N hydrogen bonds, forming pseudosymmetric trimers arranged in sheets parallel to (302).

In the title compound, C(14)H(10)F(3)N(7)·2CH(4)O, the heterocyclic ring system is essentially planar (r.m.s. deviation = 0.009 Å) and makes a dihedral angle of 6.91 (8)° with the attached benzene ring. In the crystal, the main mol-ecules form centrosymmetric R(2) (2)(8) dimers via pairs of N-H⋯N hydrogen bonds between the amino groups and pyrimidine N atoms. One of the independent methanol mol-ecules and its inversion equivalent are linked to the dimers via O-H⋯N and N-H⋯O hydrogen bonds, forming R(4) (4)(16) graph-set motifs. The dimers along with the hydrogen-bonded methanol mol-ecules are stacked along the a axis, with π-π inter-actions between the pyrazole and triazole rings [centroid-centroid distance = 3.4953 (10) Å].

Among the heterocyclic structures identified as potent human A(3) (hA(3)) adenosine receptor's antagonists, we have demonstrated that the new pyrazolo-triazolo-pyrimidines, bearing an aryl group in replacement of the C(2)-furyl ring, not only confer a good pharmacological profile (with significantly enhanced selectivity against other adenosine receptor subytpes) but also overcome the metabolic transformation of the furan ring into toxic intermediates. All the synthesized [2-(para-substituted) phenyl]-pyrazolo-triazolo-pyrimidines showed affinity at the hA(3) receptor in the low nanomolar range. The most potent derivative of the series presented better affinity and excellent selectivity (compound 31, K(i) hA(3) = 0.108 nM; hA(1)/hA(3) = 5200; hA(2A)/hA(3) = 7200), in comparison to the C(2)-furyl counterpart. A receptor-driven molecular modeling investigation, based on a recently proposed model of A(3) receptor derived from the crystallographic structure of human A(2A) receptor, has been carried out in order to support the experimental binding data and to justify the enhanced selectivity against the other receptor subtypes.

The title compound, C(6)H(8)N(6), crystallizes as an N-H⋯N hydrogen-bond-linked dimer of two almost identical mol-ecules in the asymmetric unit. Both of the mol-ecules are almost planar (rms deviations of 0.0186 and 0.0296 Å in the two molecules) and their hydrazino groups are turned towards the pyrazole rings. The dimers are arranged into chains via inter-molecular N-H⋯N hydrogen bonds between the hydrazino groups and the N atoms of the pyrimidine rings of both types of the mol-ecules, linking the mol-ecules into a C(7) graph-set motif along [100]. The methyl groups and the N atoms of the pyrazole rings form weak C-H⋯N hydrogen bonds, which connect chains of the dimers in a C(4) motif parallel to [100].

The title compound, C(12)H(16)N(12), is a centrosymmetric mol-ecule which comprises of a hexa-aza[14]annulene macrocyclic ring fused with two pyrazole rings. The macrocyclic ring is essentially planar, with an r.m.s. deviation of 0.0381 Å. The electron pairs of the amino groups are delocalized with the conjugated system of the macrocycle. Strong intra-molecular N-H⋯N hydrogen bonds arranged in an S(2) (2)(10) graph-set motif are present in the macrocyclic ring. In the crystal, the amino groups act as donors for inter-molecular N-H⋯N inter-actions with the N atoms of the heterocyclic system, forming a network of two types of extended chains oriented parallel to the [101] and [011] directions. The crystal packing is also stabilized by weak inter-molecular C-H⋯N hydrogen bonds formed between pyrazole C-H groups and N atoms of the macrocyclic ring, running in the [10] direction.

The title compound, C(13)H(9)BrF(3)N(5)O, crystallizes with two independent mol-ecules in the asymmetric unit. The pyrimidine rings of the mol-ecules are planar [maximum deviations 0.053 (3) and 0.012 (3) Å], while the triazine rings adopt flattened half-boat conformations with the p-bromo-phenyl rings in the flagpole positions. The crystal packing is stabilized by a three-dimensional network of inter-molecular N-H⋯N, N-H⋯O and N-H⋯F hydrogen bonds.