Synthesis of 1-alkyl-1,2,4-triazolium 4-nitroimides by alkylation of 4-nitramino-1,2,4-triazole salts

A method for the synthesis of 1-alkyl-1,2,4-triazolium 4-nitroimides was developed based on alkylation of 4-nitramino-1,2,4-triazole Na and Ag salts with halo- and dihaloalkanes.     

Synthesis of 1,2,4-triazolium 4N-nitroimides by the nitration of 1-substituted 4-amino-1,2,4-triazolium nitrates

A general method for the synthesis of 1,2,4-triazolium 4N-nitroimides with functionalized substituents in position 1 of the heterocycle was developed. The method is based on the nitration of the corresponding 1-R-4-amino-1,2,4-triazolium nitrates.     

Synthesis of 3,5-Diaryl-4-benzylideneamino-1,2,4-triazoles and 4-Amino-3,5-diaryl-1,2,4-triazoles

A one-pot reaction leading to 3,5-diaryl-4-benzylideneamino-1,2,4-triazoles is described, the key step of which is the reaction of arenecarbohydrazonoyl chloride with benzylidenehydrazide. Compounds obtained in this way were hydrolyzed to 4-amino-3,5-diaryl-1,2,4-triazoles.     

Reactions of 4-Aryl-1,2,4-triazolidine-3,5-dithione with Some Electrophilic Reagents

Reaction of 4-aryl-1,2,4-triazolidine-3,5-dithiones in an alkaline medium with chloroacetic acid and its derivatives, as well as with -bromo ketones, results in their conversion to 4-aryl-1,2,4-triazole-3,5-bis(sulfides). The aminomethylation in a neutral medium leads to the formation of 1-(aminomethyl)-4-aryl-1,2,4-triazolidine-3,5-dithiones.     

Synthesis and Tuberculostatic Activity of 1,3-Thiazacycloalkyl[3,2-b]-1,2,4-triazoles

The 4-hydroxyalkyl-1,2,4-triazole-3-thiones cyclization allowed us to work out the effective method of 1,3-thiazacycloalkyl[3,2-b]-1,2,4-triazoles synthesis. Some of the compounds that were obtained were tested for their tuberculostatic activity.     

A Convenient Synthesis of 1,2,4-Triazolo-1,3,5-triazin-4-ones and 1,2,4-Triazolo-1,3,5-triazin-4-thiones

The imidates derived from 3-aminotriazole 1 react with isocyanates and isothiocyanates to give corresponding 1,2,4-triazolo-1,3,5-triazin-4-ones and 1,2,4-triazolo-1,3,5-triazin-4-thiones in a 60–75% overall yield. If the condensation is realized at r.t., then the intermediate 2 can be isolated.     

Synthesis of 4-Amino-6-R-4,5-dihydro-3-phenacylthio-1,2,4-triazin-5-ones and 8H-3-R-7-Aryl-1,2,4-triazino[3,4-b][1,3,4]thiadiazin-4-ones

A study was carried out on the reaction of 4-amino-6-R-2,3,4,5-tetrahydro-3-thioxo-1,2,4-triazin-5-ones with halo ketones in alkaline media to yield 4-amino-6-R-4,5-dihydro-3-phenacylthio-1,2,4-triazin-5-ones, which then convert to 8H-3-R-7-aryl-1,2,4-triazino[3,4-b][1,3,4]thiadiazin-4-ones.     

Synthesis and Biological Activity of 3-[4H-(1,2,4)-Triazolyl]-2,6-diaryl-1,3,5-oxadiazine-4-thione

4-Amino-1,2,4-triazole (1) undergoes facile condensation with aromatic aldehydes to afford the corresponding 4-(arylidene-amino)-4H-[1,2,4]-triazole (2a–h) in good yield. Rearrangement of compounds (2a–h) with benzoyl isothiocyanate/4-chloro-benzoyl isothiocyanate/2,4-dichloro-benzoyl isothiocyanate yields corresponding 1,3,5-oxadiazine derivatives (3). Structural elucidation of these compounds was based on elementary analysis and spectral data studies. The newly synthesized compounds were evaluated for their antibacterial activities.     

福司氟康唑杂质——2-(2,4-二氟苯基)-1-(1H-1,2,4-三氮唑-1-基)-3-(4H-1,2,4-三氮唑-4-基)-2-丙基磷酸二氢酯的合成

以1,3-二氟苯为起始原料,依次经傅－克酰基化,1H-三氮唑取代,环氧化,胺解,4H-三氮唑环化,磷酸酯化和钯碳加氢反应等7步反应合成了福司氟康唑的主要杂质--2-(2,4-二氟苯基-1-(1H-1,2,4-三氮唑-1-基)-3-(4H-1,2,4-三氮唑-4-基)-2-丙基磷酸二氢酯,纯度98%,总收率7.8%,其结构经¹H NMR确证。     

微波促进下3-(2-苯并呋喃基)-4-氨基-5-巯基-1,2,4-三唑

微波辐射条件下, 首先由2-苯并呋喃甲酰肼依次与二硫化碳和水合肼反应合成3-(2-苯并呋喃基)-4-氨基-5-巯基- 1,2,4-三唑, 进一步在微波辐射条件下由4-氨基-5-巯基-1,2,4-三唑分别与芳甲酸/芳氧基乙酸、α-溴代苯乙酮及芳醛反应以较高产率制得了相应的1,2,4-三唑并[3,4-b]-1,3,4-噻二唑、1,2,4-三唑并[3,4-b]-1,3,4-噻二嗪及4-芳亚甲基亚胺基-5-巯基-1,2,4-三唑. 产物结构经IR, ¹H NMR, MS及元素分析进行了表征.     

Chloromethyl-, dichloromethyl-, and trichloromethyl-1,2,4-triazines and their 4-oxides: method for the synthesis and tele-substitution reactions with C-nucleophiles

A simple procedure was developed for the synthesis of 1,2,4-triazines and their 4-oxides containing the ClCH₂, Cl₂CH, or CCl₃ group at position 3 by cyclization of 2-aryl-2-hydrazono-1-oximinoethanes with the corresponding chloroacetonitriles. The reaction pathway depends on the number of halogen atoms in the acetonitrile used. The reactions with trichloroacetonitrile, monochloroacetonitrile, and dichloroacetonitrile afford 3-trichloromethyl-1,2,4-triazines, 3-chloromethyl-1,2,4-triazine 4-oxides, and a mixture of the corresponding dichloromethyltriazines and their 4-oxides, respectively. The reactions of 3-trichloromethyl-1,2,4-triazines with indoles and phenols are accompanied by tele-substitution with elimination of halogen from the trichloromethyl group to give 5-indolyl- (or 5-hydroxyphenyl)-3-dichloromethyl-1,2,4-triazines.     

Derivatives of 4-amino-4H-1,2,4-triazole-3-thiols linked to the pyrrole cycle and some products of their S-alkylation

This study offers an access to 21 new heterocyclic compounds representing pyrrole derivatives of 4-amino-4H-1,2,4-triazole-3-thiols or 1,3,4-oxadiazole-2-thiols. The principal synthetic approach is based on the cyclization of substituted potassium 2-(pyrrolecarbonyl)hydrazine-1-carbodithionate with hydrazine hydrate to 5-(substituted pyrrolyl)-4-amino-4H-1,2,4-triazole-3-thiols, followed by S-alkylation with methyl iodide or benzyl chloride. Among the resulted thirteen S-alkyl derivatives, five 1,3,4-oxadiazole derivatives have been isolated as secondary products and their formation is explained as being the result of S-alkylation of intermediate 1,3,4-oxa-diazole-2-thiols, generated in the alkaline medium. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 383–391, March, 2007.     

Synthesis of 1-amino-1,2,4-triazolium 4-nitroimides and their reactions with electrophiles

A procedure was developed for the preparation of 1-amino-1,2,4-triazolium 4 nitroimides by amination of triethylammonium salts of 4-nitramino-1,2,4-triazoles with O-picrylhydroxylamine. The resulting nitroimides reacted with electrophilic reagents (acyl chlorides, aldehydes, phenyl isocyanate, NO₂BF₄, etc.) at the amino group.     

Thermal decomposition of 4-amino-1,2,4-triazolium nitrate under infrared laser heating

The objective of this work is to study the behavior of an ionic liquid, 1-H-4-amino-1,2,4-triazolium nitrate, during thermal decomposition driven by an infrared laser (10.6 μm). The focus was to understand the initial decomposition reactions and subsequent reactions that lead to ring decomposition and eventually to ignition. A triple quadrupole mass spectrometer with molecular beam sampling was used to obtain gaseous decomposition species of the sample. The principal mass peaks that may contain multiple masses were analyzed through tandem mass techniques. The experiments were conducted at a laser heat flux of 100 W/cm² in helium at 1 atm. To assist in interpreting the data, three other materials were also tested, 4-amino-1,2,4-triazolium hydrochloride, 4-amino-1,2,4-triazole, and 1-H-1,2,4-triazole. The results show that the most probable route to initiate the decomposition of the 1-H-4-amino-1,2,4-triazolium nitrate is through proton transfer from N₁ site to the nitrate forming a neutral pair, nitric acid and amino-triazole. Subsequent reactions involve decomposition of the neutral pair and their interactions.     

Regioselectivity of Alkylation of 3-Substituted 5-Amino-1,2,4-thiadiazoles

We have synthesized 3-substituted 4-alkyl-5-imino-4,5-dihydro-1,2,4-thiadiazoles by reaction of 3-alkyl(benzyl)thio-5-amino-1,2,4-thiadiazoles with methyl iodide or ethylene chlorohydrin. In the reaction with epichlorohydrin, addition of an oxirane molecule occurs with formation of tetrahydropyrimido[2,1-b]-1,2,4-thiadiazoles.     

Annelation of the thiazole ring to 1,2,4-triazines by tandem AN—AN or SN H—SN H reactions

The reactions of 3-aryl-1,2,4-triazines with aromatic thioamides and 4-arylthiosemicarbazides in acetic anhydride at room temperature afforded cyclic products of the tandem nucleophilic addition reactions, viz., tetrahydrothiazolo[4,5-e]-annelated 1,2,4-triazines, in good yields. The latter underwent aromatization in the presence of potassium permanganate.     

On triazoles,IX HMO calculations of tautomeric 1,2,4-triazole derivatives

HMO calculations were performed for all possible tautomeric forms of different 1,2,4-triazole derivatives1–4 and their condensed ring analogues5–8. The resonance energies obtained showed this method useful for the differentiation of the tautomeric structure of the planar monocyclic 1,2,4-triazole derivatives but it did not give satisfactory results in case of their non-planar condensed ring analogues.

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Über Triazole, 9. Mitt.: HMO-Berechnungen tautomerer 1,2,4-Triazol-Derivate

Zusammenfassung Die HMO-Methode wurde für alle möglichen tautomeren Formen der 1,2,4-Triazol-Derivate1–4 und deren kondensierte Analogen5–8 verwendet. Die berechneten Resonanzenergien bewiesen, daß dieHückel-Methode gute Resultate für die Unterscheidung verschiedener tautomerer Formen der planaren 1,2,4-Triazol-Derivate, aber nicht für deren nicht-planare kondensierte Analogen ergibt.

     

Synthesis of 4-hydroxy-4,5-dihydro-1,2,4-triazol-5-ones

Summary A series of hydroxamic acid ethoxycarbonylhydrazides was obtained by reactions of ester ethoxycarbonylhydrazones with hydroxylamine. The corresponding 3-substituted 4-hydroxy-4,5-dihydro-1,2,4-triazol-5-ones were synthesized by cyclization of these hydroxamic acid derivatives in basic medium.

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Synthesen von 4-Hydroxy-4,5-dihydro-1,2,4-triazol-5-onen

Zusammenfassung Durch Reaktion von Esterethoxycarbonylhydrazonen und Hydroxylamin wurde eine Reihe von Hydroxamsäureethoxycarbonylhydraziden gewonnen; Cyclisierung dieser Verbindungen durch Base gab die entsprechenden 3-substituierten 4-Hydroxy-4,5-dihydro-1,2,4-triazol-5-one.

     

The Synthesis and Reactions of N-Hydroxy-3-Arylsydnone-4-Carboxamide Oximes

N-Hydroxy-3-arylsydnone-4-carboxamide oximes (7) were prepared from the corresponding 3-arylsydnone-4-carbohydroximic acid chlorides (6) and hydroxylamine in high yield. The chemical reactivity of compound (2) is somewhat different from 3-arylsydnone-4-carboxamide oximes (2) in that the former compounds reacted with both aromatic and aliphatic aldehydes in the presence of acid catalyst to give 3-aryl-4-(5-aryl-1,2,4-oxadiazol-3-yl)sydnones (5) and 3-aryl-4-(5-alkyl-1,2,4-oxadiazol-3-yl)sydnones (3).     

Facile synthesis of [1,2,4]triazino[4,3-b][1,2,4,5]tetrazepin derivatives by a one-pot reactions using 4-amino-3-hydrazinyl-6-methyl-1,2,4-triazin-5 (4H)-one

<正>4-Amino-3-mercapto-6-methyl-l,2,4-triazin-5(4H)-one 1 converted to 4-amino-6-methy-3-(methylthio)-1,2,4-triazin-5(4H)-one by methylation with methyl iodide.Controlled hydrazination of the resulting compound afforded 4-amino-3-hydrazinyl-6- methyl-l,2,4-triazin-5(4H)-one 2 as a building block,to the synthesis of some novel derivatives of[1,2,4]triazino- [4,3,b][1,2,4,5]tetrazepine 3-6,by the reaction with 3-chloropentane-2,4-dione,chloro acetonitrile,1,3-dichloroacetone,and methyl bromoacetate.This general synthetic procedure can be extended to the preparation of wide variety of tetrazepines using 1,2- bielectrophiles derivatives.