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1.
L. D. Smirnov S. V. Nikitin A. I. Chernyshev A. A. Sorokin V. P. Lezina V. G. Zabrodnyaya M. M. Kaganskii 《Chemistry of Heterocyclic Compounds》1992,28(12):1425-1431
It has been shown that the alkylation of 2-methyl-9-hydroxy-4H-pyrido[1,2-a]pyrimidin-4-one takes place at the oxygen atom, but electrophilic substitution takes place mainly at position 8 of the molecule (the ortho position relative to the hydroxy group).Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1660–1666, December, 1992. 相似文献
2.
L. D. Smirnov L. G. Stolyarova L. V. Shirokova V. P. Lezina 《Russian Chemical Bulletin》1977,26(2):408-410
Conclusions The aminomethylation, azo-coupling, and nitration of 3-hydroxyisonicotinic acid and its ester are directed to the 2 position, whereas their iodination proceeds with the formation of the 2-iodo and 2,6-diiodo derivatives.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 452–454, February, 1977. 相似文献
3.
M. M. Markova V. P. Lezina S. B. Gashev A. U. Stepanyantz B. V. Mislavskii L. D. Smirnov 《Chemistry of Heterocyclic Compounds》1991,27(1):76-80
The rate of H/D exchange among methyl group protons in a series of substituted 3-hydroxypyridines, 5-hydroxypyrimidines, and their N-oxides has been shown to increase with increasing acidity of the medium. The most reactive form of these molecules is the cationic form at pH<2. The rate of H/D exchange of CH3 group protons in 3-hydroxypyridine derivatives has also been found to be several orders of magnitude lower than the rates of exchange for methyl-substituted 5-hydroxypyrimidine and its N-oxide. Effective rate constants for methyl group proton exchange have been estimated. In the case of methyl-substituted 5-hydroxypyrimidine N-oxide derivatives it has been established that the rate of proton exchange is greater for an ortho-methyl group than for a methyl group in the para-position relative to the N-oxide site.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 93–96, January, 1991. 相似文献
4.
V. P. Lezina V. F. Bystrov B. E. Zaitsev N. A. Andronova L. D. Smirnov K. M. Dyumaev 《Theoretical and Experimental Chemistry》1972,5(2):159-163
To explain the character of the intramolecular hydrogen bond in substituted 3-hydroxypyridines, the chemical shifts in the NMR spectra of the hydroxyl group and the IR spectra were studied. It was established that the stability of the intramolecular hydrogen bond of the O-HNR2 type in substituted 3-hydroxypyridines increases when compared with the corresponding phenols, while an opposite pattern is observed for bonds of the O-H02 N type. An approximate evaluation of the energy of the intramolecular hydrogen bond in substituted 3-hydroxypyridines was achieved. When reacting with bases of the same strength, 3-hydroxypyridine forms more stable complexes than phenol. 相似文献
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7.
Yu. V. Kuznetsov L. G. Stolyarova V. P. Lezina L. D. Smirnov 《Russian Chemical Bulletin》1989,38(7):1494-1500
1. | New halogen derivatives of 1-ethyl-2-methyl-, 2-methyl- and 5-hydroxybenzimidazole were obtained. |
2. | A method for the chlorination of aromatic compounds by an alcoholic solution of hydrogen chloride in the presence of hydrogen peroxide was proposed, which enables carrying out the reaction with a high yield. |
3. | The reactivity of the series of 5(6)-hydroxybenzimidazole derivatives during the electrophilic substitution (halogenation) was shown to be as follows: 1-ethyl-2-methyl-5-hydroxybenzimidazole >5(6)-hydroxybenzimidazole 2-methyl-5-hydroxybenzimidazole. |
8.
V. L. Savel'ev O. L. Samsonova V. S. Troitskaya V. G. Vinokurov V. P. Lezina L. D. Smirnov 《Chemistry of Heterocyclic Compounds》1988,24(7):805-810
The reaction of 3,4-diaminocoumarin with thionyl chloride gave 4H-[1]benzopyrano[3,4-c][1,2,5]thiadiazol-4-one (II), which was cleaved by the action of nucleophilic agents to the corresponding 4-(2-hydroxyphenyl)-1,2,5-thiadiazole-3-carboxylic acid derivatives. The nitration of II leads to the 8-nitro or 6,8-dinitro derivative; the latter was isolated in the form of 4-(2-hydroxy-3,5-dinitrophenyl)-1,2,5-thiadiazole-3-carboxylic acid.See [3] for our preliminary communication.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 977–981, July, 1988. 相似文献
9.
L. D. Smirnov V. S. Zhuravlev V. P. Lezina B. E. Zaitsev K. M. Dyumaev 《Chemistry of Heterocyclic Compounds》1974,10(7):837-838
The halogenation of 5-benzyl-3-hydroxypyridine proceeds with the formation of 2,6-dihalo-substituted compounds. The presence of a benzyl group in the 5 position activates the 6 position of the -pyridol ring with respect to electrophilic attack.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 958–960, July, 1974. 相似文献
10.