共查询到20条相似文献,搜索用时 15 毫秒
1.
V. N. Yarovenko S. A. Kosarev A. V. Shirokov I. V. Zavarzin M. M. Krayushkin 《Russian Chemical Bulletin》2000,49(8):1481-1482
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. 相似文献
2.
V. M. Chernyshev V. A. Rakitov V. A. Taranushich V. V. Blinov 《Chemistry of Heterocyclic Compounds》2005,41(9):1139-1146
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.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1342–1350, September, 2005. 相似文献
3.
Javier de Mendoza Tomás Torres M. Dolores Badía 《Monatshefte für Chemie / Chemical Monthly》1988,119(8-9):1041-1045
Lead tetraacetate oxidation of 4-amino-1,2,4-triazoles, 1-amino- and 2-amino-1,2,3-triazoles affords mainly fragmentation to nitriles or acetylenes, even in the presence of intramolecularly attached double bonds.
Über die Bleitetraacetatoxidation von 4-Amino-1,2,4-triazolen, 1-Amino- und 2-Amino-1,2,3-triazolen (Kurze Mitteilung)
Zusammenfassung Bei der Oxidation von 4-Amino-1,2,4-triazolen, 1-Amino- und 2-Amino-1,2,3-triazolen mit Bleitetraacetat entstanden hauptsächlich Nitrile bzw. Acetylene durch Fragmentierung — trotz der Gegenwart von intramolekularen Doppelbindungen.相似文献
4.
G. T. Sukhanov A. G. Sukhanova Yu. V. Sheikov 《Chemistry of Heterocyclic Compounds》2007,43(6):786-792
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.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 927–934, June, 2007. 相似文献
5.
H. M. Dalloul N. S. Al-Abadla Kh. A. El-Nwairy 《Chemistry of Heterocyclic Compounds》2007,43(3):314-319
A new series of substituted 1,2,4-triazoles was synthesized from the cycloaddition reaction of alkanal and cycloalkanal hydrazones
containing electron-withdrawing groups (MeCO, PhCO, and MeOCO) with appropriate hydrazonoyl halides.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 392–398, March, 2007. 相似文献
6.
Safa Azzouni Abderrahmen Abdelli Anne Gaucher Youssef Arfaoui Mohamed Lotfi Efrit Damien Prim 《Tetrahedron》2018,74(49)
The reaction of variously substituted acylimidates with hydrazine derivatives represents an efficient and easy to set synthetic entry towards 5-vinyl-1,2,4-triazole derivatives. The construction of the triazole ring allows the installation of variety of substituent combination at the N(1), C(3) and C(5) positions of the five-membered heterocycle in good to high yields. The method reveals selective towards 5-vinyl-1,2,4-triazoles avoiding the potential formation of seven- and five-membered side-products as supported by theoretical calculations and NMR experiments. First lines of Pd-catalyzed arylation of the vinyl fragment towards 5-styryl-1,2,4-triazoles and Cu-catalyzed arylation at the N(1) site are finally described. 相似文献
7.
Dinneswara Reddy GudaTengjiao Wang Hyeon Mo ChoMyong Euy Lee 《Tetrahedron letters》2012,53(39):5238-5242
A mild, convenient, and efficient one-pot synthesis of mercapto-1,2,4-triazoles is described. Various hydrazides efficiently reacted with trimethylsilyl isothiocyanate (TMSNCS) under basic condition to give mercapto-1,2,4-triazoles in high yields. 相似文献
8.
A. G. Sukhanova G. V. Sakovich G. T. Sukhanov 《Chemistry of Heterocyclic Compounds》2008,44(11):1368-1373
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. 相似文献
9.
Summary After summarizing published results on silica gel and alkyl-bonded silica gel solubilities, the experimental solubility of unmodified silica and copper silicate gel (used in ligand exchange chromatography) in watermethanol-ammonia and water-acetonitrile-ammonia mixtures are given. These results demonstrate that silica gel solubility, measured by a static method, varies greatly with the water volume fraction of a ternary mixture. Curiously, no influence from the organic nature of the solvent was demonstrated. This observation is inconsistent with the fact that the copper silicate gel used in ligand-exchange chromatography with water-methanol-ammonia as mobile phase is attacked more rapidly than with water-acetonitrile-ammonia.An explanation based upon the variations of acid-base properties of silicic acid versus mobile phase dielectric constant values in conjunction with the methanol protophilic properties is proposed. Finally, it is shown that chromatographic columns filled with copper silicate gel have lifetimes of several months, if they are used with a procolumn (of copper silicate gel) and with acetonitrile as organic solvent with a volume fraction greater than 0.5 in the mobile phase. 相似文献
10.
V. L. Korolev T. V. Petukhova E. A. Bakhmatova T. S. Pivina A. B. Sheremetev 《Chemistry of Heterocyclic Compounds》2006,42(10):1267-1290
Modeling of the probable mechanisms of the thermolysis of C-and N-nitramino-1,2,4-triazoles has been carried out by methods
of mathematical chemistry. It was established that the formation is possible of a more diverse spectrum of products in their
destruction than was previously recorded by different experimental methods. Subsequent assessment of the thermochemical preference
for pathways of decomposition of the compounds was carried out by the density functional method in the B3LYP/6-31G* approach.
It was determined that the thermal destruction of C-and N-nitramino-substituted polynitrogen heterocycles, capable of tautomeric
conversion, was most probably through the thermochemically least stable nitramine form. Thermal decomposition of the considered
tautomers is preferred at the NNO2 fragment and not at the triazole ring. The direction of the structural stabilization of the investigated compounds has been
clarified by comparison of the geometric, electronic, and thermochemical characteristics of C-NNO2-and N-NNO2-substituted 1,2,4-triazoles.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1467–1495, October, 2006. 相似文献
11.
Barbara Milczarska Henryk Foks Urszula Dobrzycka Zofia Zwolska Ewa Augustynowicz-Kopeć 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):2793-2799
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. 相似文献
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13.
G. T. Sukhanov A. G. Sukhanova Yu. V. Ilyasova 《Chemistry of Heterocyclic Compounds》2006,42(9):1197-1199
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.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1378–1381, September, 2006. 相似文献
14.
V. L. Korolev T. V. Petukhova T. S. Pivina A. A. Porollo A. B. Sheremetev K. Yu. Suponitskii V. P. Ivshin 《Russian Chemical Bulletin》2006,55(8):1388-1410
Possible decomposition mechanisms of C-nitro-and N-nitro-1,2,4-triazoles were simulated. We showed that in addition to the experimentally detected thermolysis products including
N2, N2O, NO, CO2, HCN, HNCO, 1,2,4-triazole, 3(5)-nitroso-1,2,4-triazole, and 1,2,4-triazolone, some other decompositon products (H2O, CO, NO2, cyanamide, cyanuric acid, and melamine) can be formed. Using the density functional approach (B3LYP/6-31G* approximation),
we assessed the most favorable thermal decomposition pathways of nitrotriazoles and studied the relationships between the
thermolysis pathways of these substances and their molecular and electronic structures. We found a correlation between the
energy gap width (energy difference between the frontier molecular orbitals) and the stabilities of the C-nitro-1,2,4-triazole tautomers to thermal decomposition.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1338–1358, August, 2006. 相似文献
15.
K. A. Venkatesan T. G. Srinivasan P. R. Vasudeva Rao 《Colloids and surfaces. A, Physicochemical and engineering aspects》2001,180(3):234-284
Extraction of cobalt(II) ion from aqueous solution was studied using silica gel grafted with dithiocarbamate ligand (Si–dtc), which was prepared by reacting silica gel with γ-aminopropyltriethoxysilane followed by alkaline carbon disulfide. 29Si MAS NMR, IR spectra were taken to establish the grafting of dithiocarbamate ligand on silica gel. This modified surface contains 0.37 mmol g−1 of the ligand sites available for the extraction of cobalt. The sorbent extracts cobalt only when the pH of the aqueous phase is above 7 and the extraction process does not follow ideal ion-exchange mechanism. The electronic absorption spectra of cobalt present in the sorbent phase suggested the oxidation of Co(II) to Co(III). Kinetic data were fitted to surface complexation model and the rate constant (ks) for such model was found to vary from 1.5×10−3 to 5.82×10−3 l mg−1 min−1 depending on the initial concentration of cobalt. An estimate of enthalpy and entropy changes accompanying the extraction was obtained by temperature variation method. The increase in the overall entropy of the system seems to favour the extraction of cobalt by Si–dtc. 相似文献
16.
Abdallah Harizi Noureddine Saïd Zine Mighri Hédi Zantour 《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):2623-2632
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. 相似文献
17.
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. 相似文献
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