共查询到20条相似文献,搜索用时 15 毫秒
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N. V. Fedorov A. V. Anisimov E. A. Viktorova 《Chemistry of Heterocyclic Compounds》1989,25(10):1083-1096
Data on the use of the Pummerer reaction in the synthesis and transformations of various heterocyclic compounds that contain oxygen, sulfur, and nitrogen as the heteroatoms are correlated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1299–1313, October, 1989. 相似文献
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Rusanov A. L. Plieva L. Kh. Kereselidze M. K. Korshak V. V. 《Chemistry of Heterocyclic Compounds》1977,13(9):1029-1032
Two new diamines — [1,3-bis(5-phenyl-1,2,4-triazol-3-yl)-4,6-diamino]benzene and [1,3-di-(2-benzimldazolyl)-4,6-diamino]benzene — were synthesized from 4,6-dinitroisophthalic acid. Newheterocyclic systems — 3,5,9,11-tetraphenyl[benzo[1,2-a; 4,5-a]bis(1,2,4-triazolo[4,3-c]pyrimidine)] and 2,16-diphenyl[benzo[1,2-a;4,5-a']bis(pyrimido[1,6-a]benzimidazole)]—were obtained by reaction of the diamines with benzoyl chloride and subsequent cyclization.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1274–1277, September, 1977. 相似文献
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L. B. Dashkevich M. M. Samoletov M. L. Tkachenko 《Chemistry of Heterocyclic Compounds》1971,7(8):1077-1079
2-Phenyl-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrimtdine-5,7-dione reacts with several nucleophilc reagents via a scheme involving nucleophilic addition with opening of the dioxopyrimidine ring at the C-N bond in the 7–8 positions. The reaction may serve as a method for the synthesis of some asymmetrical pyrazolyl derivatives of malonic acid.See [1] for communication I.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1145–1147, August, 1971. 相似文献
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Dezs? Korbonits 《Tetrahedron》2008,64(6):1071-1076
A cotarnine alkaloid-based synthesis was developed for new heptacyclic condensed diisoquinolines via the double intramolecular pseudosalt bis[1,3]dioxolo[4,5-g;4′,5′-g′][1,3,4]oxadiazolo[2,3-a;5,4-a′]diisoquinoline 6. Substitution of the central O atom in 6 by C, S, or N nucleophiles afforded the first representatives of the new ring systems bis[1,3]dioxolo[4,5-g:4,5-g′]pyrazolo[3,2-a:5,1-a′]diisoquinoline (7a-d), bis[1,3]dioxolo[4,5-g:4,5-g′][1,3,4]thiadiazolo[2,3-a:5,4-a′]diisoquinoline (8), and bis[1,3]dioxolo[4,5-g:4,5-g′][1,2,4]triazolo[3,2-a:5,1-a′]diisoquinoline (9a-d) under simple reaction conditions. 相似文献
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In order to study the intramolecular hydrogen bond, angular condensed heterocyclic derivatives of naphthalene containing a hydroxyl group in the peri position with respect to the nitrogen atom of the heterocycle have been synthesized. 相似文献
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Curves are derived for the effective yield of negative ions from the interaction of electrons with thiophene, 2-methylthiophene, 2-propylthiophene, 3-methylthiophene, 3-propylthiophene, furan, and selenophene. It is found that there are two quasi-stationary states of the molecular negative ions having lifetimes of about 10–14 and 4 · 10–15 sec. The cross sections for formation of these states are estimated, and also the cross sections for resonant elastic scattering of electrons. The states are shown to be related to excited states of the molecule. It is found that alkyl substitution has the following effects on resonant electron capture: a) reduces the probability of ring breakage and b) reduces the energy levels of the quasi-stationary state. Some aspects of dissociative ionization are discussed. 相似文献
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Syntheses of some hydroxylaminoazines, their quaternized derivatives or N-oxides and N-amino compounds are described. Several transformations of these compounds and cyclization reactions are presented. 相似文献
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L. I. Belen'kii 《Chemistry of Heterocyclic Compounds》1993,29(7):835-843
A summary is given for new syntheses of heterocycles starting with trichloromethylarenes and the readily available products of the addition of carbon tetrachloride to functional derivatives of olefins. Applications of the electrophilic trichloromethylation for benzene and thiophene compounds are considered. Information is given on the reactions of trichloromethylarenes with heteronucleophiles, in particular, leading to the synthesis of diaryl-1,2,4- and diaryl-1,3,4-oxadiazoles. The reaction of trichloromethylarenes and pyridines to give the corresponding aromatic aldehydes and N-(4-pyridyl)pyridinium dichloride is discussed.Dedicated to Professor A. R. Katritzky on the occasion of his sixty-fifth birthday.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 980–990, July, 1993. 相似文献
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Reactions involving the catalytic dehydrocyclization of synthetically accessible substituted pyridine bases, as a result of which condensed nitrogen-containing heterocyclic compounds containing three, four, and five rings are formed, are examined.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1011–1021, August, 1988. 相似文献
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《Arabian Journal of Chemistry》2014,7(5):639-646
Herein we have studied the cytotoxicity and quantitative structure–activity relationship (QSAR) of heterocyclic compounds containing cyclic urea and thiourea nuclei. A set of 22 hydantoin and thiohydantoin related heterocyclic compounds were investigated with respect to their LC50 values (Log of LC50) against brine shrimp lethality bioassay in order to derive the 2D-QSAR models using MLR, PLS and ANN methods. The best predictive models by MLR, PLS and ANN methods gave highly significant square correlation coefficient (R2) values of 0.83, 0.81 and 0.91 respectively. The model also exhibited good predictive power confirmed by the high value of cross validated correlation coefficient Q2 (0.74). 相似文献
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Institute of Bioorganic Chemistry, Academy of Sciences of Belarus, 220141 Minsk. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 715-716, May, 1995. Original article submitted May 6, 1995. 相似文献
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G. N. Dorofeenko V. I. Volbushko V. I. Dulenko E. N. Kornilova 《Chemistry of Heterocyclic Compounds》1976,12(9):977-980
Substituted benzo[b]thieno[3,2-b]pyrylium salts and dibenzo[b,g]thieno[3,2-b; 2, 3-e]pyrylium salts, which are converted to the corresponding pyridines on refluxing with ammonium acetate in glacial acetic acid, were synthesized by acid condensation of 3-thioindoxyl with aldehydehydes of the aromatic and heteroaromatic series in the presence of perchloric acid.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1181–1185, September, 1976. 相似文献
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Clifford C. Leznoff Polina I. Svirskaya Varda Yedidia Jack M. Miller 《Journal of heterocyclic chemistry》1985,22(1):145-147
The uracil analog, 4-fluoro-2-pyridone was synthesized by ether cleavage of 4-fluoro-2-methoxypyridine with trimethylsilyl iodide. Improved procedures for the preparations of 2-methoxypyridine N-oxide hydrochloride and 2-methoxy-4-nitropyridine N-oxide are described. 相似文献
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Summary The stereochemistry of the reaction of 1-alkyl-4-piperidones with phenyllithium depends not only on steric factors, but also on the character of the nitrogen-attached alkyl group. The effect of alkyl groups is associated with fixation of the direction of the dipole of the nitrogen atom, as a result of which the predominant direction of reaction becomes that for which the free electron pair of the nitrogen and the C-O bond of the enolate ion then arising occupy antiparallel directions. 相似文献
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