Synthesis of 4-amino-4,5-dihydro-1H-1,2,4-triazole-5-ones and their isatin-3-imine derivatives

Iminoester hydrochlorides 1 have been synthesized. These compounds were then converted into ester ethoxycarbonyl hydrazones 2, from which in turn a new series of substituted 4-amino-4,5-dihydro-1H-1,2,4-triazole-5-ones, 3, was then prepared.Finally a set of isatin imine derivatives 4 was obtained from the reaction of compounds 3 with isatin. The structures of all the new synthesized compounds were confirmed by elemental analyses, IR, (1)H-NMR and (13)C-NMR spectra.     

A study on 4-acylamino-4,5-dihydro-1H-1,2,4-triazol-5-ones

Five novel 3-alkyl-4-phenylacetylamino-4,5-dihydro-1H-1,2,4-triazol-5-ones (2) were synthesized by the reactions of 3-alkyl-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones (1) with phenylacetyl chloride and characterized by elemental analyses and IR, 1HNMR, 13C-NMR and UV spectral data. The newly synthesized compounds 2 were titrated potentiometrically with tetrabutylammonium hydroxide in four non-aqueous solvents such as isopropyl alcohol, tert-butyl alcohol, acetonitrile and N,N-dimethylformamide, and the half-neutralization potential values and the corresponding pKa values were determined for all cases. In addition, these new compounds and five recently reported 3-alkyl-4-(pmethoxybenzoylamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones (3) were screened for their antioxidant activities.     

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.

     

3-甲基-4-氨基-1,2,4-三唑-5-硫酮席夫碱的合成及生物活性研究

用自制的二氨基硫脲与乙酸反应得到3-甲基-4-氨基-1,2,4-三唑-5-硫酮, 然后以醋酸为反应溶剂和催化剂, 使之与取代芳香醛反应, 合成了8个三唑类席夫碱化合物. 通过¹H NMR, IR和元素分析对所有化合物进行了结构表征. 并对这些化合物进行了初步生物活性测试, 结果表明大部分化合物具有较好的抑菌活性, 并对席夫碱结构与活性的关系进行了探讨.     

Synthesis of some new 4,5-substituted-4H-1,2,4-triazole-3-thiol derivatives

In this study appropriate hydrazide compounds, furan-2-carboxylic acid hydrazide (1) and phenylacetic acid hydrazide (2) were converted into 1,4-substituted thiosemicarbazides 4a-e and 5a-e and 4-amino-5-(furan-2-yl or benzyl)-4H-1,2,4-triazole-3-thiols 7 and 10. The 1,4-substituted thiosemicarbazides were then converted into 5-(furan-2-yl or benzyl)-4-(aryl)-4H-1,2,4-triazole-3-thiols 8a-e and 9a-e. In addition, the azomethines 11a-d and 12a-d were prepared from the corresponding arylaldehydes and the 4-amino-5-(furan-2-yl or benzyl)-4H-1,2,4-triazole-3-thiols 7 and 10. The structures of all the synthesized compounds were confirmed by elemental analyses, IR, (1)H-NMR and(13) C-NMR spectra.     

Synthesis of Trifluoroalkyl- and Fluoroaryl-Substituted 4,5-Dihydro-1H-1,2,4-triazole-5-thiones

Reactions of 4-(4-fluorophenyl)-, 4-(4-trifluoromethoxyphenyl)-, 4-(3,4-difluorophenyl)-, 4-(4-trifluoromethylphenyl)-, 4-piperidino-, and 4-(3-pyridyl)thiosemicarbazides with esters gave the corresponding 3,4-disubstituted 4,5-dihydro-1H-1,2,4-triazole-5-thiones and their S-alkyl derivatives. Analogous reactions with methyl 2,2,3,3,4,4,5,5-octafluoropentanoate and 2,2,3,3,4,4,5,5-octafluoropentanenitrile afforded, respectively, the acylation and addition products.     

Ene Synthesis of Bicyclic Arylmethylenedihydropyrazoles Using 4-Phenyl-4,5-dihydro-3H-1,2,4-triazole-3,5-dione

8-Acetyl-7-aryl-2-arylmethylene-8,9-diaza- and 4,8,9-triazabicyclo[4.3.0]non-9-enes react with4-phenyl-4,5-dihydro-3H-1,2,4-triazole-3,5-dione, following the ene addition pattern. Under similar conditons 7-aryl-2-arylmethylene-8-methyl-8,9-diazabicyclo[4.3.0]non-9-enes give rise to both mono- and polyadditionproducts. The product structures were studied by ¹H and ¹³C NMR, IR, and UV spectroscopy and singlecrystal X-ray diffraction.     

Synthesis and non-aqueous medium titrations of some new 4-benzylidenamino-4,5-dihydro-1H-1,2,4-triazol-5-one derivatives

The synthesis of 3-alkyl(aryl)-4-(3-ethoxy-4-hydroxybenzylidenamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones 3 from the reactions of 3-alkyl(aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones 2 with 3-ethoxy-4-hydroxybenzaldehyde is described.The acetylation and methylation reactions of the compounds 3 giving compounds of type 4 and 5, respectively, were investigated. The newly synthesized compounds were characterized using elemental analyses and IR, (1)H-NMR, (13)C-NMR and UV spectral data.In addition, to investigate the effects of solvents and molecular structure upon acidity,compounds 3 were titrated potentiometrically with tetrabutylammonium hydroxide in four non-aqueous solvents (isopropyl alcohol, tert-butyl alcohol, acetonitrile and N,N-dimethylformamide). The half-neutralization potential values and the corresponding pKa values were determined for all cases.     

4-氨基-5-烃基-2,4-二氢-3H-1,2,4-三唑-3-硫酮席夫碱的简便合成

近年来,人们发现标题类杂环席夫碱能发生很多新颖的反应,且其中许多具有强的生物活性［１～７］．但其制备多以乙醇为反应介质,以酸或碱为催化剂,反应需经数小时,后处理也比较麻烦．本文报道了题示席夫碱的一种极为简便的合成方法,反应介质选用低级的脂肪酸（如冰醋...     

N-多氟烷基取代和葡萄糖基取代的1,2,4-三唑-5-硫酮类席夫碱的合成及其杀虫活性

为改善三唑类化合物的生物活性, 以3-苯基-4-氨基-1,2,4-三唑-5-硫酮为原料, 将其与芳香醛在冰醋酸体系中反应, 得到3-苯基-4-芳基亚甲氨基-1,2,4-三唑-5-硫酮类席夫碱(4a～4i). 在此基础上, 化合物4a～4i分别与多氟烷基碘代烷和溴代乙酰基葡萄糖反应合成了一系列1,2,4-三唑-5-硫酮类席夫碱的多氟烷基取代物5a～5r和葡萄糖基取代物6a～6d, 并用¹H NMR, ¹⁹F NMR, IR和MS谱以及元素分析表征了它们的结构. 初步生物活性测试结果表明, 部分目标化合物具有明显的杀虫活性.     

Synthesis of 1-amino-5-phenyl-4,5-dihydro-3H-2-benzazepines and the isomeric 2-amino-1-benzazepines

The title amidines (1 and 2) were synthesized. A synthesis of lactam 10 free of isomeric 4 is described. An interesting rate difference in displacement of thiomethyl ether intermediates 5 and 11 with amines was observed.     

5-氨基-1H-1,2,4-三氮唑-3-硫代-2''''-丙酸乙酯类Schiff碱的合成与表征

用氨基三氮唑硫代丙酸乙酯与取代苯甲醛反应,合成了6个新型的5-氨基-1H-1,2,4-三氮唑-3-硫代-2′-丙酸乙酯类Schiff碱,其结构经1H NMR, IR, MS和元素分析表征.     

Synthesis, acidity and antioxidant properties of some novel 3,4-disubstituted-4,5-dihydro-1H-1,2,4-triazol-5-one derivatives

3-Alkyl(aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones 2a-g reacted with 4-diethylaminobenzaldehyde to afford the corresponding 3-alkyl(aryl)-4-(4-diethyl-aminobenzylidenamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones 3a-g. The acetylation reactions of compounds 3a-e were investigated and compounds 4a-e were thus obtained. The new compounds were characterized using IR, (1)H-NMR, (13)C-NMR, UV and MS spectral data. In addition, the newly synthesized compounds 3a-g were titrated potentiometrically with tetrabutylammonium hydroxide in four non-aqueous solvents such as isopropyl alcohol, tert-butyl alcohol, acetone and N,N-dimethylformamide (DMF), and the half-neutralization potential values and the corresponding pKa values were determined for all cases. Moreover, 3 and 4 type compounds were also screened for their antioxidant activities.     

4,5-dihydro-5,5-dimethyl-3-oxo-3H-1,2,4-triazole-1-oxide. The unpredicted azoxy-regioisomer

Summary 4,5-Dihydro-5,5-dimethyl-3-oxo-3H-1,2,4-triazole (1) is converted to the title azoxy compound4 by peroxytrifluoroacetic acid. The structure assignment of4 is based on an X-ray analysis.Ab initio calculations were employed to rationalize the reaction path leading to the triazole-1-oxide4 and not to the expected regioisomer triazole-2-oxide3.

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4,5-Dihydro-5,5-dimethyl-3-oxo-3H-1,2,4-triazol-1-oxid. Das unerwartete Regioisomere

Zusammenfassung 4,5-Dihydro-5,5-dimethyl-3-oxo-3H-1,2,4-triazol (1) wird mit Trifluorperessigsäure in die Titel-Azoxy-Verbindung4 umgewandelt. Die Strukturzuordnung von4 basiert auf einer Röntgenstrukturanalyse. Mittelsab initio-Rechnungen wird versucht zu erklären, weshalb die Reaktion zum Triazol-1-oxid4 und nicht zum erwarteten regioisomeren Triazol-2-oxid3 führt.