Reactions of 3-Nitro-1,2,4-Triazole Derivatives with Alkylating Agents. 2. Alkylation of a Neutral Heterocycle by Dimethyl Sulfate

The reaction of 3-nitro-1,2,4-triazole and 5-methyl-3-nitro-1,2,4-triazole with dimethyl sulfate leads to mixtures of N-mono- and N,N-dimethylnitrotriazolium compounds and products of the subsequent conversion of the latter, namely, N,N-dimethyl-1,2,4-triazol-5-ones. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1168–1173, August, 2005.     

Reactions of 3-nitro-1,2,4-triazoles with alkylating agents. 6*. Alkylation of a neutral heterocycle by alcohols in acid media*

Reaction of 3-nitro-1,2,4-triazole and 5-methyl-3-nitro-1,2,4-triazole with secondary and tertiary alcohols in conc. H₂SO₄ takes place at the N(2) atom. Alkylation by 2-propanol occurs regioselectively to form the 1-isopropyl-3-nitro-and 1-isopropyl-3-methyl-5-nitro-1,2,4-triazoles. As a consequence of isomerization the alkylation using cyclohexyl or tert-butyl alcohols gives respectively a mixture of regioisomers substituted at atom N(1) (1-cyclohexyl-3-nitro-and 1-cyclohexyl-5-methyl-3-nitro-1,2,4-triazoles) and at atom N(2) (5-nitro-1-cyclohexyl-and 1-cyclohexyl-3-methyl-5-nitro-1,2,4-triazoles) and, in the second case, to 1-tert-butyl-3-nitro-1,2,4-triazole. * For Communication 5 see [1]. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1680–1687, November, 2008.     

Reactions of 3-nitro-1,2,4-triazole derivatives with alkylating agents. 5. Selective synthesis of 1,4-dialkyl-and 1,4,5-trialkyl-3-nitro-1,2,4-triazolium salts from 1-alkyl-and 4,5-dialkyl-3-nitro-1,2,4-triazoles and dialkyl sulfates

Interaction of N₍₁₎-alkyl-substituted 3-nitro-5-R-1,2,4-triazoles with dialkyl sulphates proceeds selectively and results in the respective salts of 1,4-dialkyl-, 1,4,5-trialkyl-3-nitro-1,2,4-triazoliums. The reaction of N₍₄₎-alkyl-substituted 3-nitro-5-R-1,2,4-triazoles yields the mixtures of the salts of 1,4-dialkyl-, 1,4,5-trialkyl-3-nitro-1,2,4-triazoliums and 1,4-dialkyl-, 1,3,4-trialkyl-1,2,4-triazol-5-ones with predominance of quaternary salts. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 927–934, June, 2007.     

Reactions of 3-nitro-1,2,4-triazoles with alkylating agents. 3. Alkylation of a neutral heterocycle by diethyl sulfate

The reaction of 3-nitro-5-R-1,2,4-triazoles with diethyl sulfate gives 1-ethyl-3-R-5-nitro-, 4-ethyl-3-nitro-5-R-1,2,4-triazoles, 1,4-diethyl-, 1,4-diethyl-3-methyl-1,2,4-triazol-5-ones, and 1,4-diethyl-3-nitro-5-R-1,2,4-triazolium salts. When compared with the use of dimethyl sulfate as alkylating agent the ethylation products have a markedly increased fraction of triazolones (up to 30–37%) and a somewhat lowered yield of nitrotriazolium salts (up to 6–10%). The reaction time is increased by an order. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1378–1381, September, 2006.     

Alkylation of acyl and sulfonyl derivatives of 3,5-diamino-1-phenyl-1,2,4-triazole

Alkylation of 3-acylamino-, 5-amino-1-phenyl-3-tosylamino-1,2,4-triazoles and 3,5-diacetylamino-1-phenyl-1,2,4-triazole in the presence of an equimolar amount of sodium methylate in DMSO occurs regioselectively at the amide (sulfamide) group nitrogen atom. The benzylation of 3-acetylamino-5-amino-1-phenyl-1,2,4-triazole with excess base and benzyl chloride also alkylates the amino group at position 5. Alkylamino-1-R-1,2,4-triazoles can be conveniently prepared by alkylation of the corresponding acetylamino-1,2,4-triazoles in the presence of base and subsequent acid hydrolysis of the N-acetyl-N-alkyl derivatives. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 557–567, April, 2009.     

Acyl and Sulfonyl Derivatives of 3,5-Diamino-1-R-1,2,4-triazoles

3-Acylamino-5-amino-1-R-1,2,4-triazoles are formed regioselectively on acylating 3,5-diamino-1-R-1,2,4-triazoles with an equimolar amount of anhydrides, carboxylic acid chlorides, and sulfonyl chlorides. With an excess of anhydride and carboxylic acid chloride 3,5-diacylamino-1-R-1,2,4-triazoles are formed. 3-Acylamino-5-amino-1-R-1,2,4-triazoles do not interact with sulfonyl chlorides. The higher reactivity of the 3-amino group towards acylating agents is determined by electronic and not steric factors. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1342–1350, September, 2005.     

Thermal Decomposition of 3-Nitro-1-nitromethyl-1,2,4-1H-triazole in Solution

The thermal decomposition of 3-nitro-1-nitromethyl-1,2,4-1H-triazole in 1% solution in phenyl benzoate proceeds homolytically with initial rupture of the CH₂-NO₂ bond. Activation parameters of the process were E _a = 172.6 kJ/mol, log A = 14.25. The initial basic pathway of fragmentation of the molecule under electron impact coincides with the first step of thermal decomposition, which is in agreement with X-ray structural and calculated quantum chemical data on bond stability in the molecule.     

Indirect Electrochemical N-Dimethoxyphenylation of 3-Nitro-1,2,4-triazole and Tetrazole

Using the obtaining of 1,4-dimethoxy-2-(3-nitro-1,2,4-triazole-1-yl)benzene (I) and 1,4-dimethoxy-2-(tetrazolyl-1+-2)benzene (II) as an example, a method for indirect electrosynthesis of these substances is developed. In the first stage of this process, electrosynthesis of 1,1,4,4-tetramethoxycyclohexane-2,5-diene is realized by means of oxidation of 1,4-dimethoxybenezene on a platinum anode in an environment of MeOH in a diaphragmless cell. In the second, chemical interaction of this diene with 3-nitro-1,2,4-triazole and tetrazole is performed when heating a mixture of these substances for a long time at 110°C in the presence of additives of collidine. As a result, target products I and II were obtained with a good (60–90%) yield. Realization of this process opens new possibilities for producing N-arylazoles.__________Translated from Elektrokhimiya, Vol. 41, No. 8, 2005, pp. 1014–1019.Original Russian Text Copyright © 2005 by Burasov, Vakhotina, Petrosyan.     

Thermal Decomposition of Ammonium 3-Nitro-1,2,4-triazol-5-onate Monohydrate

The thermal decomposition of ammonium 3-nitro-1,2,4-triazol-5-onate monohydrate[NH4（NTO）·H2O] was studied by means of thermal analysis-MS coupling and the combination technique of in situ thermolysis cell with rapid-scan Fourier transform infrared spectroscopy. The results show that there are two endothermic steps and one exothermic step in the decomposition process of NH4（NTO）·H2O. The detected gas products consist of NH3, H2O, N2, CO2, CO, and NO2.     

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.     

Synthese de 5-Aryl-3-[(1-dialcoxyphosphonyl)methyl]-1,2,4-triazoles a Partir d'Imidates N-Chloroacyles

A variety of 5-aryl-3-[(1-dialcoxyphosphonyl)methyl]-1,2,4-triazoles 3 has been synthesized efficiently by treatment of trialkylphosphites with 5-aryl-3-chlorométhyl-1,2,4-triazoles 2 . Compound 2 has been prepared by action of N-chloroacylimidates 1 with hydrazines. The structure of triazoles 2 and 3 have been unequivocally confirmed by means of IR, 1 H, 13 C, 31 P NMR spectroscopy and mass spectra.     

Reaction of crown ethers with five-membered heterocycles: 1H-imidazole-4,5-dicarbonitrile, 3-nitro-1,2,4-triazole, and 1H-tetrazole

By the reaction of 1H-imidazole-4,5-dicarbonitrile, 3-nitro-1,2,4-triazole, and 1H-tetrazole, containing one proton at each of the two proton-donating atoms separated by one covalent bond, it was shown that uncharged crystalline supramolecular compounds can be obtained on account of the proton-donating characteristics of the aromatic heterocycles. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1302–1305, September, 2006.     

3-硝基-1，2，4-三唑-5-酮铅金属盐快速热分解反应动力学研究

利用温度快速跃升傅立叶变换红外原位分析技术对3-硝基-1，2，4-三唑-5-酮铅盐的快速热分解反应动力学进行了研究。借助快速升温过程中Pt金属丝的控制电压变化曲线得到剧烈放热峰的诱导出现时间t_x，利用t_x值计算得到了快速热分解过程的动力学参数。在0.1 MPa氩气气氛，230～270 ℃实验温度范围内，3-硝基-1,2,4-三唑-5-酮铅金属盐的活化能E_a=94.0 kJ·mol^-1，lnA=20.5。同时得到了该化合物快速热分解过程的近似吉布斯自由能变，熵变和焓变。该方法借助温度快速跃升技术，在模拟材料实际使用情况下计算得到其动力学参数，可用于含能材料燃烧模型的建立。     

Synthesis of 3-carbamoyl-1,2,4-triazoles

3-Carbamoyl-1,2,4-triazoles were synthesized by the reaction of monothiooxamides with acid hydrazides Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1487–1488, August, 2000.     

3-硝基-1,3,4-三唑-5-酮金属(Li,Na, Pb,Cu)盐的制备反应热动力学

在常压、298.15 K条件下, 用RD496-2000微量热仪开展了3-硝基-1,3,4-三唑-5-酮(NTO)金属(Li, Na,Pb, Cu)盐制备反应的热动力学研究, 得到了反应过程中的热力学参数(活化焓、活化熵和活化自由能), 速率常数和动力学参数(活化能、指前因子和反应级数), 还得到了在25-40℃范围内NTO金属(Li, Na, Pb, Cu)盐制备反应过程的反应焓. 结果表明, NTO金属(Li, Na, Pb, Cu)盐的制备反应较容易发生. 基于Hess定律, 得到了Δ_fH_m⁰ (Li(NTO)·2H₂O, aq, 298.15 K)和Δ_fH_m⁰ (Na(NTO)·H₂O, aq, 298.15 K)的值.     

Synthesis of 3-(3-Alkyl-5-thioxo-1H-4,5-dihydro-1,2,4-triazol-4-yl)aminocarbonylchromones

A series of 3-(3-alkyl-5-thioxo-1H-4,5-dihydro-1,2,4-triazol-4-yl)aminocarbonylchromones has been prepared by oxidation of 3-formylchromone with Jones' reagent followed by reaction with 3-alkyl-4-amino-4,5-dihydro-1,2,4-triazole-5(1H)-thione in the presence of POCl³. The structures of the compounds were confirmed by IR, LC-MS, and ¹H NMR spectra and elemental analyses.     

Non-isothermal Kinetics of the Thermal Decomposition of 3-Nitro-1,2,4-triazol-5-one Magnesium Complex

Introduction3 Nitro 1,2 ,4 triazol 5 one (NTO)metalcomplexeshavemanyspecialstructuresandsomepotentialusesinammunition .1 4 Wepreviouslypreparedanddeterminedthecrystalstructureofitsmagnesiumcomplex ,5andinthispaper ,wediscusseditsthermalbehaviorbyDSCandTG/DTGtechniquesandstudieditsnon isothermalkineticsbythemeansoftheKissingermethod ,theOzawamethod ,thedifferentialmethodandtheintegralmethod .ExperimentalSample[Mg(H2 O) 6 ](NTO) 2 ·2H2 Owaspreparedasfollows :AcalculatedamountofMg(OH…     

3-硝基-1,2,4-三唑-5-酮与NH3及H2O分子间相互作用的理论研究

在DFT-B3LYP/6-311＋＋G**水平上, 求得3-硝基-1,2,4-三唑-5-酮(NTO)/NH₃和NTO/H₂O两种超分子体系势能面上5种全优化构型. 经基组叠加误差(BSSE)和零点能(ZPE)校正, 求得NTO与NH₃和H₂O的分子间最大相互作用能依次为－37.58和－30.14 kJ/mol, 表明NTO与NH₃的分子间相互作用强于与H₂O的作用. 超分子体系中电子均由NH₃或H₂O向NTO转移, 相互作用能主要由强氢键所贡献, 由自然键轨道分析揭示了相互作用的本质. 对优化构型进行振动分析, 并基于统计热力学求得200.0～800.0 K温度范围从单体形成超分子的热力学性质变化. 发现由NTO和NH₃形成超分子II和III在常温下可自发进行; 而NTO和H₂O只在低温下才能自发形成IV, V和VI超分子.     

NTO二聚体分子间相互作用的理论研究

在DFT-B3LYP/6-311＋＋G**水平上求得NTO二聚体势能面上六种优化构型和电子结构. 经基组叠加误差(BSSE)和零点能(ZPE)校正, 求得分子间最大相互作用能为－53.66 kJ/mol. 二子体系间的电荷转移很少. 由自然键轨道分析揭示了相互作用的本质. 对优化构型进行振动分析, 并基于统计热力学求得200.0～800.0 K温度范围从单体形成二聚体的热力学性质变化. 发现二聚主要由强氢键所贡献, 但结合能大小并不为氢键所完全决定. 二聚过程在较低温度或常温下能自发进行.