Substitution of Cyano Group in Position 5 of 1,2,4-Triazines by Carboxylic Acid Hydrazide Residues under Solvent-Free Conditions

Russian Journal of Organic Chemistry - The possibility of substitution of the 5-cyano group in 1,2,4-triazines by carbohydrazide residues under solvent-free conditions with high yields has been...     

One-Pot Preparation Method of 5-Alkyl-3-(benzo)pyridyl-1,2,4-triazines

Russian Journal of Organic Chemistry - Convenient one-pot method was developed for the preparation of 5-alkyl-3-(2-pyridyl)-, 5-alkyl-3-(4-pyridyl)- or 5-alkyl-3-(quinolin-2-yl)-1,2,4-triazines in...     

Modeling of 1,2,4,5-tetrazine complexes with organic amines

Tetrazine complexes with organic ligands have been modeled. The composition and structure of the model complexes agree with experimental data. The structure and nature of the complexes affect a number of chemical reactions of 1,2,4,5-tetrazines with organic amines. It is shown that the possibility and route of nucleophilic substitution in the 3 and 6 positions of the tetrazine ring are provided by amine localization in the tetrazine complex and also by the orbital characteristics of the reagents. The route and possibility of cycloaddition reactions for tetrazines are dictated by the ability of the latter to form π-complexes with reagents and by the orbital characteristics of the complexes. The route of the cycloaddition reaction is also affected by the solvent.     

Nitro azines. 21. Reactivities and electron structures of 6-nitroazolo[1,5-a]pyrimidines

6-Nitroazolopyrimidines react with the acetonyl anion to give 6-nitro-7-acetonyl-4,7-dihydroazolo[1,5-a]pyrimidines. The reactivity of this class of compounds with respect to charged and uncharged nucleophiles is determined by their aromatic character and the deficit of electron density in the pyrimidine ring, while the direction of attack is determined by the overall charge on fragments of the valence-bonded atoms.For Communication 20 see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 807–813, June, 1993.     

Nitroazines. 8. Reactions of 6-nitroazolo[1,5-a]pyrimidines with pyrroles

The reactions of 6-nitroazolo[1,5-a]pyrimidines with pyrroles have been examined, and the influence of substitution in the azole moiety of the substrate on the course of the reaction studied. The formation of two isomeric sigma-adducts has been established by spectroscopy.For Communication 7, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1251–1255, September, 1988.     

5-Acylmethyl-3-(2-pyridyl)-1,2,4-triazines: Synthesis and Complexes with Cu(II)

5-Acylmethyl-3-(2-pyridyl)-1,2,4-triazines are easily prepared from accessible 3-(2-pyridyl)-1,2,4-triazine 4-oxides by reaction of the latter with acetophenone or trifluoroacetone in the presence of NaH. The compounds obtained behaved as efficient ligands in reaction with CuCl₂ furnishing dimeric neutral complexes with Cu(II) whose structure was investigated by means of X-ray diffraction analysis.     

Asymmetric induction in the reactions of 3-aryl-1,2,4-triazin-5(4H)-ones with C-nucleophiles

3-Aryl-1,2,4-triazin-5(4H)-ones, in the presence of N-protected amino acids, react with C-nucleophiles to form 1-acyl-6-Nu-3-aryl-1,6-dihydro-1,2,4-triazin-5(4H)-ones in high diastereomeric excess. This is the first case of the use of amino acids as chiral auxiliaries in nucleophilic additions to triazinones.     

Synthesis and hydroxydeamination in the series of 6-aryl- and 6-benzoimidazolyl-7-aminoazolo[5,1-c]-1,2,4-triazines

The replacement of the amino group with the hydroxy group was examined in the series of 6-aryl- and 6-benzoimidazolyl-7-aminoazolo[5,1-c]-1,2,4-triazines. These reactions provide a convenient synthetic procedure for the preparation of fused azolo[5,1-c]-1,2,4-triazin-7-ones.     

An efficient route to 5-(hetero)aryl-2,4′- and 2,2′-bipyridines through readily available 3-pyridyl-1,2,4-triazines

A new route to substituted bipyridines based on a new method for the synthesis of substituted 3-pyridyl-1,2,4-triazines and their aza-Diels-Alder reactions is shown to be an efficient strategy for the preparation of structurally diverse bipyridine ligands.     

Nitroazines. 10. Addition of polyatomic phenols to 6-nitroazolo[1,5-a]pyrimidines

Products of addition of polyphenols to 6-nitroazolo[1,5-a] pyrimidines without activation of the reagent and the substrate were obtained. The effect of substitution in the polyphenols and azolopyrimidines on the course of the process was examined.See [1] for Communication 9.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 811–816, June, 1989.