ChemInform Abstract: Nucleophilic Substitution of the Nitro Group in 4,5‐Dinitro‐2‐alkyl‐1, 2,3‐triazoles.

Shafeev, M. A.; Meshcheryakov, V. I.; Al'mukhamedov, A. A.; Gareev, G. A.; Vereshchagin, L. I.

doi:10.1002/chin.199534037

Cited by 2 publications

(6 citation statements)

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“…The signal of the labeled nitrogen atom of the nitro group at position 5 of the heterocycle remains in the 15 N NMR spectra of the nucleophilic substitution product 64 [69]. Substitution of the second nitro group by the action of nucleophiles does not occur even under rigid conditions on account of deactivation of the heterocycle as a result of the electron-donating effect of the amino group.…”

Section: Reactions Of the Substituentsmentioning

confidence: 95%

“…Nucleophilic substitution of one of the nitro groups by an azide fragment takes place very readily. The electron-withdrawing azido group in the obtained 2-alkyl-4-azido-5-nitro-1,2,3-triazoles leads to the result that it is possible to substitute the second nitro group after prolonged reaction and to obtain 2-alkyl-4,5-diazido-1,2,3-triazoles 65 [69].…”

Section: Reactions Of the Substituentsmentioning

confidence: 96%

“…However, the regioselectivity of nucleophilic substitution at the carbon atoms in the heterocycle depends largely on the different reactivity of the groups being substituted. Thus, in 5-bromo-4-nitro-2-(4-nitrophenyl)-1,2,3-triazole 1-oxide (69) only the halogen atom at position 5 is substituted selectively in reaction with methylamine [69]. Apart from the nitro group, chemical modifications of other substituents in nitrotriazole molecules have been described in the literature.…”

Section: Alk Alkmentioning

confidence: 97%

“…For the preparation of this compound it is better to use the nitration of 2-alkyl-4-methylamino-5-nitro-1,2,3-triazole 67 with concentrated HNO 3 in trifluoroacetic anhydride. Nucleophilic substitution of the nitro group by the action of such a weak nucleophile as the methylnitramine anion takes place much more readily in 4,5-dinitro-2-(4-nitrophenyl)-1,2,3-triazole 1-oxide (18) and leads to the formation of 4-methylnitramino-5-nitro-2-(4-nitrophenyl)-1,2,3-triazole 1-oxide (68) [69]. As in the reaction with methylamine the nitro group at position 4 of the triazole oxide ring undergoes nucleophilic substitution.…”

Section: Alk Alkmentioning

confidence: 99%

“…The reaction took 1-2 h and led to the respective aminotriazoles with yields of 50-75% [48]. π-Electron-deficient 2-alkyl-4,5-dinitro-1,2,3-triazoles 63 enter into nucleophilic substitution reactions, in which the leaving group is one of the nitro groups [69]. The reaction with very active nucleophiles such as the methoxide anion is exothermic.…”

Section: Reactions Of the Substituentsmentioning

confidence: 99%

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Synthesis and properties of nitro-1,2,3-triazoles (Review)

Vereschagin

Pokatilov

Kizhnyaev

2008

Chem Heterocycl Comp

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Published data on methods for the synthesis of substituted 4(5)-nitro-1,2,3-triazoles and their properties are reviewed.Against the background of the extremely large amount of published information about methods for the production of vicinal triazoles and their properties the chemistry of nitro-substituted triazoles of this series is in an embryonic state. At the same time, according to existing data, vicinal nitrotriazoles may find use in the synthesis of medicines, dyes, agents for the struggle against agricultural pests, energy-rich components of propellants, special-purpose powders, and in other regions of technology. However, the practical application of these compounds has been restrained by the lack of technologically convenient methods for their production. Until now sufficiently effective preparative methods have not been developed for their synthesis. With respect to their properties it is known only that the nitro group of the triazoles is capable of being reduced catalytically to an amino group and substituted by various nucleophilic fragments, while the triazole ring is alkylated by alkyl halides and adds to an activated multiple bond. The limited information is probably explained by the poor availability of vicinal nitrotriazoles, which is most likely due to the passivity of the 1,2,3-triazole in electrophilic substitution reactions at carbon atoms and particularly in nitration processes. In this connection it seems expedient to examine methods for the synthesis of nitro-substituted 1,2,3-triazoles by direct nitration with due regard to the conditions determining the entry of the nitro group into the azole ring and also methods for the construction of nitrotriazoles by the cyclization of open-chain nitro compounds and to assess their properties. SYNTHESIS OF NITRO-1,2,3-TRIAZOLES Nitration of 1,2,3-TriazolesThe inertness of the carbon atoms of the triazole ring toward electrophilic reagents is due to distribution of the electron density of the ring in such a way that the carbon atoms carry a partial positive charge, preventing the addition of a nitronium cation. Therefore, the path to direct nitration of the ring of unsubstituted vicinal triazole has not so far been realized. Attempts to introduce a nitro group into the ring of the heterocycle of 1-phenyl-and 4-phenyl-1,2,3-triazoles were unsuccessful. 1-Phenyl-1,2,3-triazole (1) does not form 4(5)-nitrosubstituted triazole during nitration even under rigid conditions. Here, only the phenyl ring is nitrated-initially at the para position and then at the ortho position [1-3].

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Section: Reactions Of the Substituentsmentioning

confidence: 95%

Section: Reactions Of the Substituentsmentioning

confidence: 96%

Section: Alk Alkmentioning

confidence: 97%

Section: Alk Alkmentioning

confidence: 99%

Section: Reactions Of the Substituentsmentioning

confidence: 99%

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