Pyrazolo[4,3-e][1,2,4]triazines: purine analogues with electronic absorption in the visible region.

SYNTHESIS AND STRUCTURE ELUCIDATION OF 1,2,4-TRIAZINO [4,3-b] 1,2,4-TRIAZINES, 1,2,4-TRIAZINO [3,4-C] 1,2,4-TRIAZINES AND 1,2,4-TRIAZINO [4,3-dl l,2,4-TRIAZINES

1,3-Dimethyl-5-methyl­sulfonyl-1H-pyrazolo­[4,3-e][1,2,4]triazine

In the title compound, C(7)H(9)N(5)O(2)S, the pyrazolo-[4,3-e][1,2,4]triazine fused-ring system is essentially planar [maximum deviation = 0.0420 (3) Å]. In the crystal, mol-ecules related by twofold axes are linked into a mol-ecular net via inter-molecular C-H⋯O and C-H⋯N hydrogen bonds. π-π inter-actions are observed between the triazine and pyrazole rings of mol-ecules related by the the two...

Synthesis and isomerization of some novel pyrazolopyrimidine and pyrazolotriazolopyrimidine derivatives.

4-Imino-1-p-tolyl-1,4-dihydropyrazolo[3,4-d]pyrimidin-5-ylamine (2) and (1-p-tolyl-1H-pyrazolo[3,4-d]pyrimidin-4-yl)-hydrazine (3) were prepared starting from ethyl 4-cyano-1-p-tolyl-1H-pyrazol-5-ylimidoformate (1). The structure of compound 3 was confirmed through preparation of the pyrazole derivatives 4 and 5. Also, the synthesis and structural characterization of pyrazolo[4,3-e][1,2,4]triaz...

The Influence of the 1-(3-Trifluoromethyl-Benzyl)-1H-Pyrazole-4-yl Moiety on the Adenosine Receptors Affinity Profile of Pyrazolo[4,3-e][1,2,4]Triazolo[1,5-c]Pyrimidine Derivatives

A new series of pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidine (PTP) derivatives has been developed in order to explore their affinity and selectivity profile at the four adenosine receptor subtypes. In particular, the PTP scaffold was conjugated at the C2 position with the 1-(3-trifluoromethyl-benzyl)-1H-pyrazole, a group believed to confer potency and selectivity toward the human (h) A2B ade...

Synthesis and antimicrobial activity of some new pyrazole, fused pyrazolo[3,4-d]-pyrimidine and pyrazolo[4,3-e][1,2,4]-triazolo[1,5-c]pyrimidine derivatives.

Hydrazonyl bromides 2a,b reacted with active methylene compounds (dibenzoylmethane, acetylacetone, ethyl acetoacetate, phenacyl cyanide, acetoacetanilide, ethyl cyanoacetate, cyanoacetamide and malononitrile) to afford the corresponding 1,3,4,5- tetrasubstituted pyrazole derivatives 5-12a,b. Reaction of 12a,b with formamide, formic acid and triethyl orthoformate give the pyrazolo[3,4-d]pyrimidi...