111,926 research outputs found
8-Azapurine nucleus: a versatile scaffold for different targets
No full text8-Azapurine nucleus is a bioisoster of the purine nucleus. Variously substituted 8-azapurines have been synthesised and studied for their interactions with many enzymes and receptors and for their antitumor and antiviral activity. In this paper the main results of the studies made in these last years
on this topic are reported
1,2,3-TRIAZOLO[4,5-e]-1,2,4-TRIAZOLO[3,4-c]PYRIMIDINES
No full textSome new 1,2,3-triazolo[4,5-e]-1,2,4-triazolo[3,4-c]pyrimidines were prepared starting from the corresponding 1,2,3-triazolo[4,5-d]pyrimidines via the formation of the 1,2,4-triazole ring. Thus suitable hydrazino derivatives 6 were condensed with triethyl orthoformate, triethyl orthoacetate and triethyl orthobenzoate to give the expected tricyclic derivatives 7, 8 and 9. Intramolecular cyclization of the ethoxycarbonylhydrazino derivatives 10 gave the tricyclic compounds 11 bearing an hydroxyl group in the 3 position. The v-triazolo-s-triazolopyrimidine derivatives were tested towards the A1 and A(2A) adenosine receptors in binding assays, but they did not show any receptor affinity
1,2,3 Triazolo[1,2-a]benzotriazoles or 2,3-Benzo-1,3a,6,6a-Tetraazapentalenes
No full textSome new v-triazolo[1,2-a]benzotriazoles or 2,3-benzo-1,3a,6,6a-tetraazapentalenes were prepared according to previously employed synthetic routes concerning deoxycyclization reactions of appropriate nitrophenyl-1,2,3-triazole derivatives and/or thermal decompositions of appropriate azidophenyl-1,2,3-triazoles. The nitration of 9-phenyl-1,2,3-triazolo[1,2-a]benzotriazoles allowed the isolation of some mononitro- and trinitro-derivatives, whose structures were assigned by chemical and spectroscopic methods
N(9)-substituted 2-phenyl-N(6)-benzyl-8-azaadenines: A1 adenosine receptor affinity. A comparison with the corresponding N(6)-substituted 2-phenyl-N(9)-benzyl-8-azaadenines
No full textThe synthesis and the assay of title compounds were accomplished. Biological results indicated the general lack of activity among the tested disubstituted compounds hearing the benzyl group on N(6) and confirmed the activity of those with this group on N(9)
NEW 1,2,3-TRIAZOLO[4,5-E]1,2,3-TRIAZOLO[4,3-C]PYRIMIDINE DERIVATIVES.II
No full textThe 7-chloro-3-(2-chlorobenzyl)- and 7-chloro-3-(2-fluorobenzyl)-1,2,3-triazolo[4,5-d]pyrimidines (1 and 4), by nucleophilic replacement with some hydrazides, gave the corresponding 7-hydrazidoderivatives (2a-e and 5a-e). These, by heating in Dowtherm, underwent an intramolecular cyclization to form the new tricyclic 7-substituted-3-(2-chlorobenzyl)- and 3-(2-fluorobenzyl)-1,2,3-triazolo[4,5-e]1,2,4-triazolo[4,3-c]pyrimidines (3a-d and 6a-d). The 7-hydrazino-3-(2-chlorobenzyl)- and 7-hydrazino-3-(2-fluorobenzyl)-triazolo-pyrimidines (9a and 9b) were also prepared via the corresponding mercapto (7a and 7b) and thiomethyl (8a and 8b) derivatives
"One Pot" Synthesis of 2-Substituted 9-(2'-Hydroxy-3'-aminopropyl)-8-azahypoxanthines and 8-Azaadenines [5-Substituted 3-(2'-Hydroxy-3'-aminopropyl)-7-amino and 7-hyroxy- 3H-1,2,3-triazolo[4,5-d]pyrimidines]
No full textAn example of the generalization of the synthesis of 8-azahypoxanthines A and 8-azaadenines B, interesting from a medicinal point of view, is presented by utilizing 1-amino-2-hydroxy-3-azidopropanes
Modification of the 1,2,3-Triazole Ring Present in an Effective in vitro Inhibitor of Prostaglandin Synthesis
No full text1,2,3-Triazolo[4,5-d]-1,2,4-triazolo[4,3-b]pyridazines
No full textSome new 1,2,3-triazolo[4,5-d]-1,2,4-triazolo[4,3-b]pyridazines were prepared starting from the corresponding 1,2,3-triazolo[4,5-d]pyridazines via the formation of the 1,2,4-triazole ring, by condensation of an appropriate monocarbon fragment with the 4-hydrazino substituent and the nitrogen atom in the 5 position of the heterocycle. Condensation of 4-phenylhydrazino substituted derivatives with formic acid gave zwitterionic compounds
In vitro Inhibitors of Prostaglandin Synthesis: (p-Thiosubstituted)-Benzyl Nitrogen Heterocycles
No full textXanthine Oxidase (XO). Synthesis of 4(5)-Carbxyamido-5(4)-aminoalkanoyl)amino-1,2,3-triazoles and Their Cyclization to 8-Azahypoxanthines. Evaluation for Inhibition of XO.
No full textSynthesis of hypoxanthine and triazole derivatives by reaction of 4(5)-amino-5(4)-carboxyamido-1,2,3-triazole with protected aminoacids are reported. The synthesized compounds had no inhibitory activity on Xanthine Oxidase
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