Direction of glycosylation of 5-substituted 4-chloro-1,2,3-triazoles

The structures of previously obtained nucleosides of 5-substituted 4-chloro-1, 2,3-triazoles were refined by means of high-resolution mass spectrometry and ¹³C NMR spectroscopy. It is shown that fusion of 5-substituted 4-chloro,1,2,3-triazoles with tetra-0-acylribofuranoses in the presence of di(p-nitrophenyl) phosphate leads to the formation of 2-nucleosides of the corresponding triazoles. The signals of the carbon atoms in the ¹³C NMR spectra of the 4,5-di-substituted triazoles and their nucleosides were assigned.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 937–940, July, 1987.     

4-Aryl(benzyl)sulfonyl-2-chloro-5-polyfluoroalkyl-1,2,3-triazoles. The first monocyclic N-chloro-1,2,3-triazoles

Treatment of 4-aryl(benzyl)sulfonyl-5-polyfluoroalkyl-v-triazoles with NaOCl gave the 4-aryl(benzyl)-sulfonyl-2-chloro-5-polyfluoroalkyl-v-triazole derivatives which contain a chlorine atom only on the N₍₂₎ atom of the heterocycle. The structure of 2-chloro-5-(1,1,2,2,3,3-hexafluoropropyl)-4-(p-tolyl-sulfonyl)-2H-[1,2,3]triazole has been established by X-ray structural investigation. The presence of a highly polarized N—Cl bond with a positive halogen atom causes the N-chlorotriazoles to react with KCN and KF as strong acids to form the potassium salts of the triazoles and to form 4-arylsulfonyl-2-(2-chloro-1-ethoxyethyl)-5-polyfluoroalkyl-2H-[1,2,3]triazoles with vinyl ethyl ether. It was found that chlorination of 4-arylsulfonyl-5-polyfluoroalkyl-v-triazoles in the presence of KF gives 4-chloro-5-polyfluoroalkyl-2H-[1,2,3]triazoles. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1342–1352, September, 2007.     

Synthesis of 1-alkyl-4(5)-hydroxymethyl-1,2,3-triazoles

An in situ method for the synthesis of 1-alkyl-4(5)-hydroxymethyl-1,2,3-triazoles by the action of acetylenic alcohols with alkyl azides as the latter are formed from sodium azide and alkyl halides in dimethylformamide is proposed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1688–1689, December, 1980.     

Synthesis of 4-Aryl-5-nitro-1,2,3-triazoles

Russian Journal of Organic Chemistry -     

A photolabile linker for the solid-phase synthesis of 4-substituted NH-1,2,3-triazoles

This communication presents the synthesis of a novel photolabile azidolinker based on the o-nitroveratryl group. The application of this linker for the synthesis and photolytic release of NH-1,2,3-triazoles is described.     

5-substituted 3-nitro-1-trinitromethyl-1,2,4-triazoles

A number of 5-R-substituted 3-nitro-1-trinitromethyl-1H-1,2,4-triazoles (R = Me, Cl, Br, N₃, NH₂, NO₂) were synthesized by nitration of the corresponding ω-(5-R-3-nitro-1H-1,2,4-triazol-1-yl)alkan-2-ones with mixtures of concentrated sulfuric and nitric acids.     

5-卤代1,2,3,-三唑互变异构的密度泛函理论研究

用密度泛函B3LYP/6-311 G**方法,对气相和水相中的1,2,3三,-唑及5-卤(-F、C l和-B r)代1,2,3,-三唑互变异构体进行了几何构型全自由度优化,获得了它们在气相和水相中的几何结构和电子结构。计算结果显示,在气相和水相中1,2,3三-唑和5-卤代1,2,3三-唑的N2-H型要比对应的N1-H型和N3-H型稳定。讨论了不同的取代基团和溶剂化效应对互变异构体的几何结构、能量和电荷分布以及互变异构反应活化能的影响带。并进一步研究了N1-H、N2-H和N3-H型三唑之间的互变异构机理:(a)分子内质子转移;(b)水助质子转移。计算结果表明,途径(b)所需要的活化能较小,为120.06KJ/mol,途径(a)为204.12KJ/mol。     

Studies on 1,2,3-triazoles. Part XI. A new entry to the benzopyrano[2,3-D]-1,2,3-triazole system. Cyclization of 1-benzyl-5-chloro-4-(2-hydroxybenzoyl)-1H-1,2,3-triazoles

The acylation of simple arenes such as benzene and alkylated benzenes with N-protected 5-chloro-1H-1,2,3-triazole-4-carboxylic acid chlorides under Friedel-Crafts conditions results in excellent yields of the corresponding ketones. Resorcinol dimethyl ethers undergo similar acylation reactions in somewhat lower yield with concomitant monodemethylation, and these derivatives undergo a facile base mediated cyclization to 9-oxo-3H,9H-benzopyrano[2,3-d]-1,2,3-triazoles.     

Reactivity of N-(1,2,4-triazolyl)-substituted 1,2,3-triazoles

Synthetically useful rhodium(II) carbenes were obtained from N-(1,2,4-triazolyl)-substituted 1,2,3-triazoles and Rh(II) carboxylates. The electron-withdrawing 1,2,4-triazolyl group reveals the heretofore unknown reactivity of nonsulfonyl 1,2,3-triazoles, which exhibit the reactivity of diazo compounds. The resulting carbenes provide ready asymmetric access to secondary homoaminocyclopropanes (80-95% ee, dr >20:1) via reactions with olefins and also engage in efficient transannulation reactions with nitriles.     

The 5-chloro-1-alkoxy-1,2,3-benzotriazole system

The 5-chloro-1-alkoxy-1,2,3-benzotriazole system has been synthesized and characterized via its physical and chemical properties. HMO calculations predict the most reactive sites on the molecule.     

Nano-copper catalyzed three-component reaction to construct 1,4-substituted 1,2,3-triazoles

Three-component reaction of alkyl halides, sodium azide with terminal alkynes can be catalyzed by nano-copper particles under ambient conditions. A series of 1,4-disubstituted-1,2,3-triazoles were obtained regioselectively by this one-pot strategy. Nano copper can be reused at least three times without significant deactivation.     

Arylhydrazononitriles as precursors to 2-substituted 1,2,3-triazoles and 4-amino-5-cyano-pyrazole derivatives utilizing microwave and ultrasound irradiation

Abstract

Cyanoacetamides 3a–d were prepared by reacting ethyl cyanoacetate with primary aliphatic amines 2a–d. The formed cyanoacetamides 3a–d were coupled with aromatic diazonium salts to give the corresponding arylhydrazones 4a–i which were used as precursors to title triazoles and pyrazoles by reacting with hydroxylamine and chloroacetonitrile. Yields of products formed by conventional heating are compared with those of microwave and ultrasound irradiation     

DABCO-mediated aza-Michael addition of 4-aryl-1H-1,2,3-triazoles to cycloalkenones. Regioselective synthesis of disubstituted 1,2,3-triazoles

Aza-Michael addition of 4-aryl-1H-1,2,3-triazoles to 2-cycloalken-1-ones has been studied in the presence of DABCO as organic base. The reactions were carried out in acetonitrile at room temperature to provide 2,4-disubstituted 2H-1,2,3-triazoles as major adducts and 1,4-disubstituted 1H-1,2,3-triazoles as minor adducts. Though the reaction times are longer (4–8 days), the two regioisomers were separated by using column chromatography and the adducts were obtained in very good to excellent combined chemical yields. The electron-rich and electron-poor substituents on aryl moiety of 4-aryl-triazoles could tolerate the reaction conditions to afford the title adducts.     

Mass-spectrometric study of isomeric 5-amino-1,2,3-thiadiazoles and 5-mercapto-1,2,3-triazoles

The behavior of the isomeric 5-amino-1,2,3-thiadiazoles and 5-mercapto-1,2,3-triazoles under electron impact was studied. It was shown that mass spectrometry can serve as a rapid and reliable method for the identification of these compounds. Key factors in the assignment of a compound to one or the other class are the peaks of the [M-N₂]⁺ ions, which are more intense in the case of the thiadiazoles, and the ions determined by the decomposition of the prototropic forms of the triazoles. The compositions of the ions were determined by the high-resolution mass spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 681–689, May, 1987.     

Synthesis and properties of 4-substituted 5H-1,2,3-dithiazol-5-ylidenes

Substituted ethanone oximes react with S₂Cl₂ and pyridine to give 1,2,3-dithiazolium chlorides. The treatment of these products with malonodinitrile in dichloromethane affords 4-substituted 5 H-1,2,3-dithiazol-5-ylidenes. The reaction of the latter compounds with n-butylamine unexpectedly yielded addition products at one of the nitrile groups, viz. substituted 1,2,3-dithiazol-5-ylideneethanimidamides.     

Efficient,mild synthesis of N-unsubstituted 1,2,3-triazoles from methanolysis of 1-sulfonyl-1,2,3-triazoles

A small library of diverse N-unsubstituted 1,2,3-triazoles was prepared from the corresponding 1-sulfonyl-1,2,3-triazoles, which were treated only with MeOH at reflux temperature. This process was carried out in good yields showing high efficiency and good functional group tolerance.     

Synthesis of 4-Arylselanyl-1H-1,2,3-triazoles from Selenium-Containing Carbinols

In this work, we present a simple way to achieve 4-arylselanyl-1H-1,2,3-triazoles from selenium-containing carbinols in a one-pot strategy. The selenium-containing carbinols were used as starting materials to produce a range of selanyl-triazoles in moderate to good yields, including a quinoline and Zidovudine derivatives. One-pot protocols are crucial to the current concerns about waste production and solvent consumption, avoiding the isolation and purification steps of the reactive terminal selanylalkynes. We could also isolate an interesting and unprecedented by-product with one alkynylselenium moiety connected to the triazole.