Fluoroalkyl-containing lithium β-diketonates in the synthesis of 1,2,4-triazolo[1,5-a]pyrimidines

Cyclocondensation of fluorine-containing lithium -diketonates with 3-amino-1,2,4-triazoles afforded 7-fluoromethyl-1,2,4-triazolo[1,5-a]pyrimidines.     

Nitroazines. 9. Characteristic features of nucleophilic substitution of the nitro group in dihydroazolo[5,1-c] [1,2,4]triazines

The reaction of 6-nitro-7-oxo-4,7-dihydroazolo[5,1-c]-1,2,4-triazines with O-, N-, and S-nucleophiles leads to the corresponding 6-substituted compounds. In the reaction of 2,4-dimethyl-6-nitro-7-oxo-4,7-dihydro-1,2,4-triazolo[5,1-c][1,2,4]triazine with hydrazine hydrate, 3-methyl-5-(N-methylamino)-1,2,4-triazole is formed.Article 8, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 253–257, February, 1989.     

Synthesis of acyclic nucleosides based on 1,2,4-triazolo[3,2-<Emphasis Type="Italic">c</Emphasis>][1,2,4]triazin-7-ones

A new class of acyclic nucleosides based on 6-phenyl-1,2,4-triazolo[3,2-c][1,2,4]triazin-7-ones was synthesized and structurally characterized for the first time.     

Reduction of nitro derivatives of azolo[5,1-c][1,2,4]triazines

Reduction of6-nitro-7-oxo-4,7-dihydroazolo[5,1-c][1,2,4]triazines into the corresponding amines with sodium dithionite takes place smoothly in neutral aqueous solutions. The structural effects in reduction of nitroazoloazines were evaluated electrochemically.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 674–677, May, 1992.     

Synthesis of 8-Aryl[1,2,4]triazolo[1,5-d][1,2,4]triazin-5(6H)-ones by S HN Reactions

A new procedure has been proposed for the synthesis of 8-aryl[1,2,4]triazolo[1,5-d][1,2,4]-triazin-5(6H)-ones by reaction of 6-aryl-1,2,4-triazin-3(2H)-ones with hydrazides derived from aliphatic, aromatic, and heterocyclic carboxylic acids. The process invloves nucleophilic substitution of hydrogen (S_N ^H)in aryltriazinones, oxidative closure of azole ring, and Dimroth rearrangement.     

Adamantylation of 3-Nitro- and 3-Ethoxycarbonyl-1,2,4-triazolo[5,1-c]-1,2,4-triazin-4-ones

Reaction of 3-nitro- and 3-ethoxycarbonyl-1,2,4-triazolo[5,1-c]-1,2,4-triazin-4-ones with 1-adamantanol (or 1-adamantyl nitrate) in concentrated sulfuric acid or with 1-bromoadamantane in sulfolane affords N-adamantyl derivatives. The adamantylation of 3-nitro-1,4-dihydro-7H-1,2,4-triazolo[5,1-c]-1,2,4-triazin-4-one yields a mixture of N⁸- and N¹-isomers that undergo interconversion in concentrated sulfuric acid along intermolecular mechanism.     

Synthesis of (7-polyfluoroalkyl)pyrazolo[1,5-a]pyrimidines based on lithium fluorine-containing β-diketonates

The reactions of Li enolates of fluorine-containing -diketones with 3-aminopyrazoles afforded (7-polyfluoroalkyl)pyrazolo[1,5-a]pyrimidines. The structure of 3-bromo-2-methyl-5-phenyl-7-trifluoromethylpyrazolo[1,5-a]pyrimidine was established by X-ray diffraction analysis.     

Nitroazines. 7. Alkylation of 6-nitro-7-oxo-4,7-dihydroazolo[5,1-c][1,2,4]-triazines and identification of the products

Reaction of 6-nitro-7-oxo-4,7-dihydroazolo[5,1-c][1,2,4]triazines with methyl iodide or dimethyl sulfate affords the N-methyl derivatives, no O-alkylation products being found. The effect of the alkylating agent, solvent, and the azole moiety on the course of the reaction has been examined.For Communication 6, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1543–1550, November, 1987.