共查询到20条相似文献,搜索用时 31 毫秒
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We have studied the basicity of 2-phenyl-5-R-1,3,4-oxadiazoles (R = H, Me, CH2Ph, t-Bu, CH2Cl, CCl3, CF3) in aqueous sulfuric acid solutions. These compounds are weak organic bases (pKBH
+ is −1.8 to −5.2). The values of pKBH
+ determined on the H0 and X acidity function scales agree well with each other. The substituent at the 5 position has a substantial effect on the
basicity of the 1,3,4-oxadiazole ring.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 748–756, May, 2006. 相似文献
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Reaction with acetylacetone in the series of 3-arylmethylene-substituted furan-2-ones and pyrrol-2-ones was studied. 8-R-4-Acyl-5-aryl-3-oxo-9-oxabicyclo[4.3.0]nona-1,7-dienes
and N-tolyl-8-R-4-acyl-5-aryl-3-oxo-9-azabicyclo[4.3.0]nona-1,7-dienes were synthesized.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, 1457–1462, October, 2007. 相似文献
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V. N. Bodnar V. N. Britsun M. O. Lozinskii 《Chemistry of Heterocyclic Compounds》2003,39(8):1018-1021
It has been established that interacting ethyl 2-arylhydrazono-4-arylthio-3-oxobutyrates with hydrazine, methylhydrazine, and phenylhydrazine forms 4-arylhydrazono-3-arylthiomethyl-4,5-dihydro-1H-1-R-pyrazolones. 相似文献
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Reactions of 3-R-5-nitropyridines with nucleophiles: Nucleophilic substitution vs conjugate addition
Maxim A. Bastrakov Vladislav V. Nikol’skiy Alexey M. Starosotnikov Ivan V. Fedyanin Svyatoslav A. Shevelev Daniil A. Knyazev 《Tetrahedron》2019,75(47):130659
A number of 3-R-5-nitropyridines were synthesized and their reactions with various types of nucleophiles were investigated. The reaction outcome depends on the nature of a nucleophile: in case of anionic O-, N- and S-nucleophiles the previously unreported substitution of non-activated nitro group occurred while carbon nucleophiles underwent dearomatization of the pyridine ring with the formation of products of 1,2- and 1,4-addition. 相似文献
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V. N. Britsun 《Chemistry of Heterocyclic Compounds》2008,44(10):1262-1266
The cyclocondensation products of N-aryl-3-oxobutanethioamides with 5-amino-3-R-4-R1-pyrazoles are 4-(arylamino)-2-methyl-7-R-8-R1-pyrazolo[1,5-a]pyrimidine and pyrazolo[1,5-a]pyrimidine-4-thione derivatives, the ratio of which depends on the nucleophilicity of the starting 5-amino-3-R-4-R1-pyrazoles and the presence of a proton donor solvent.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1550-1555, October, 2008. 相似文献
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T. A. Rumyantseva E. S. Tarasova E. S. Maltseva G. P. Shaposhnikov 《Russian Journal of General Chemistry》2020,90(1):118-122
Metal complexes (metal: ligand = 1 : 1) have been obtained via the reaction of 4-R-5-nitrophthalonitriles with erbium and lutetium acetates and chlorides. 1 : 2 heteroleptic complexes have been synthesized based on them, containing unsubstituted and octasubstituted phthalocyanine ligands at the metal atom. The products have been characterized by a set of physico-chemical methods. 相似文献
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We have established that when 5-chloro-6-[cyano(2,3-dihydro-1-R-benzo[d]azol-2-yl)methyl]-2,3-pyrazinedicarbonitriles are reacted with nucleophilic reagents (aliphatic and aromatic amines, hydrogen sulfide), annelation of the five-membered ring occurs on the [b] face of the pyrazine with formation of 6-amino-7-hetaryl-5-R-5H-pyrrolo[2,3-b]pyrazine-2,3-dicarbonitriles and 6-amino-7-(1H-benzo[d]imidazol-2-yl)thieno[2,3-b]pyrazine-2,3-dicarbonitrile respectively. Further heating with excess of acylating reagent leads to formation of a novel heterocyclic system 1H-benzo[4,5]imidazo[1,2-c]pyrazino[2',3':4,5]pyrrolo[3,2-e]pyrimidine. Reaction of vicinal dinitriles with hydrazine hydrate leads to the novel system 1H-pyrrolo[2',3':5,6]pyrazino[2,3-d]pyridazine. 相似文献
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I. D. Sadekov A. A. Ladatko E. I. Sadekova G. N. Dorofeenko V. I. Minkin 《Chemistry of Heterocyclic Compounds》1981,17(3):248-251
10-Telluroniaanthracene perchlorates with various substituents in the 9 position were obtained by the action of 70% HClO4, on 9-R-10-tellura-9-anthracenols and of trityl perchlorate on 9-R-10-tellura-9-anthracenols and 9-R-9H-10-telluraanthracenes. The IR, UV, and PMR spectral characteristics of the products' were investigated.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 343–346, March, 1981. 相似文献
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S. N. Shurov I. A. Zhikina I. B. Podvintsev 《Russian Journal of Organic Chemistry》2002,38(6):862-867
3-Reactions of 5-aryl, 5-heteryl, and 5-styryl-2,3-dihydro-2,3-furandiones with phenylbenzoyldiazomethane gave rise to 5-substituted 3-dipenylmethylene-2,3-dihydro2-furanones. The possible intermediates and reaction products were investigated by semiempirical SCF MO LCAO method in AM1 approximation. 相似文献
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P. L. Trakhtenberg M. N. Zemtsova A. N. Gusarov V. P. Zvolinskii A. E. Lipkin 《Chemistry of Heterocyclic Compounds》1979,15(6):608-611
The electronic structures and reactivity indexes (RI) of 2-(4-R-2-quinolyl)thiophenes and 5-(4-R-2-quinolyl)-2,2-dithienyls (R = H, COOH, COOC2H5, and NHCOCH3) and their protonated forms were calculated by the Pariser-Parr-Pople (PPP) method. The peculiarities of the geometrical and -electron structures were established. The calculated reactivity indexes are compared with experimental data on the electrophilic substitution reactions of the investigated compounds. A qualitative agreement between the calculated values and the experimental data was established. It is shown that quinoline derivatives of thiophene are less reactive than the corresponding dithienyl compounds in electrophilic substitution reactions.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 751–754, June, 1979. 相似文献
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Giuseppe Werber Francesco Buccheri Nicolb Vivona Manila Gentile 《Journal of heterocyclic chemistry》1977,14(8):1433-1434
The behaviour of phenylglyoxal thiosemicarbazones towards aqueous sodium hydroxide have been studied. Examples of addition compounds, 5-hydroxy-5-phenyl-2,3,4,5-tetrahydro-1,2,4-triazine-3-thiones, are reported. 相似文献
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Synthesis and reactions of 1-R-3-benzoyl-5-ethoxycarbonyl-6-oxo-1,2,3,6-tetrahydropyridine-2-thiones
V. N. Britsun A. N. Esipenko A. N. Chernega E. B. Rusanov M. O. Lozinskii 《Chemistry of Heterocyclic Compounds》2007,43(11):1411-1419
Cycloacylation of N-R-3-oxo-3-phenylpropanethioamides by diethyl ethoxymethylenemalonate occurs selectively to form 1-R-3-benzoyl-5-ethoxycarbonyl-6-oxo-1,2,3,6-tetrahydropyridine-2-thiones
which are convenient starting materials for the synthesis of bi-and tricyclic hetero systems including the previously unknown
9-R-7-ethoxycarbonyl-5-phenyl-8,9-dihydropyrido[2,3-d][1,2,4]triazolo[1,5-a]-pyrimidin-8-ones.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1660–1669, November, 2007. 相似文献
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Egorov IN Tseitler TA Kovalev IS Slepukhin PA Rusinov VL Chupakhin ON 《The Journal of organic chemistry》2012,77(14):6007-6013
Reactions between substituted 1,2,4-triazines and ketones were investigated. General procedures for one-pot synthesis of hydrogenated derivatives of such polycyclic systems as benzo[c][1,2,4]triazino[1,6-a][2]azecine, [1,2,4]triazino[1,6-f]phenantridine, and dicyclopenta[b,d]pyrido[1,2-f][1,2,4]triazine are described. 相似文献