排序方式: 共有15条查询结果,搜索用时 15 毫秒
1.
Esikov K. A. Morozova S. E. Malin A. A. Ostrovskii V. A. 《Russian Journal of Organic Chemistry》2002,38(9):1370-1373
Treatment of N-acetyl-(RS)-phenylalanine and N-acetyl-(RS)-leucine methyl esters with the system tetrachlorosilane-sodium azide leads to formation of tetrazole-containing amino acid derivatives. The latter can be converted into -substituted 5-methyl-1-tetrazolylacetic acids and the corresponding bis-tetrazoles. 相似文献
2.
K. A. Esikov V. Yu. Zubarev E. V. Bezklubnaya A. A. Malin V. A. Ostrovskii 《Chemistry of Heterocyclic Compounds》2002,38(8):986-991
We have obtained 5-phenyltetrazol-2-ylalkanoic acids and their derivatives containing terminal nitrile, amide, and tetrazol-5-yl groups. Tetrazolylalkanoic acids with two (pK
a 4.93) and three (pK
a 5.45) bridging methylene groups are weaker acids than the corresponding ditetrazoles pK
a 4.68 and 5.29 respectively). However, the acidity of 5-phenyltetrazol-2-ylacetic acid (pK
a 3.12), is higher than acidity of the corresponding ditetrazole (pK
a 3.27). 相似文献
3.
S. E. Morozova A. V. Komissarov K. A. Esikov V. Yu. Zubarev A. A. Malin V. A. Ostrovskii 《Russian Journal of Organic Chemistry》2004,40(10):1532-1538
Linear polynuclear tetrazole-containing compounds were synthesized. Alkylation of 5-[-(5-phenyl-2-tetrazolyl)alkyl]tetrazoles with ethyl bromoacetate and chloroacetamide gave the corresponding esters and amides. Treatment of the latter with tetrachlorosilane-sodium azide afforded compounds containing three tetrazole rings linked through polymethylene bridges. Acid ionization constants of the products possessing an NH-tetrazole ring (pK
a = 2.9–3.2) and the corresponding carboxylic acids (pK
a = 2.9–3.1) in aqueous methanol were determined by potentiometric titration.Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 10, 2004, pp. 1580–1586.Original Russian Text Copyright © 2004 by Morozova, Komissarov, Esikov, Zubarev, Malin, Ostrovskii. 相似文献
4.
Osipov D. A. Smirnov I. V. Grinyaev K. V. Korotaev A. D. Pinzhin Yu. P. Ditenberg I. A. Korchagin M. A. Esikov M. A. Mali V. I. 《Russian Physics Journal》2021,64(8):1460-1467
Russian Physics Journal - A comparative study of microstructure parameters and mechanical property characteristics of consolidated Ni3Al samples formed by spark plasma sintering after a preliminary... 相似文献
5.
6.
The paper gives data on isotope composition of interstitial and near-bottom waters sampled in a region of gas-hydrate formation in the Sea of Okhotsk. The studies shows that heavy isotope of oxygen and hydrogen is used in gas-hydrate formation, with the result that isotope composition of its constitution water constitutes δ18O = +1.99‰, δD = +23‰ relatively to SMOW. Formation of autogenic carbonates leads to isotope exchange with interstitial water wich, in turn, changes its primary isotope composition in the direction of increasing of O-18 content. The near-bottom waters are isotope-light relatively to the SMOW standard and to the mean isotope composition of interstitial water in the studied region of gas-hydrate spreading. 相似文献
7.
8.
The review analyzes published data on the synthesis, chemical properties, and application of 1-substituted 5-alkyl(aryl)sulfanyltetrazoles. Specific attention is given to reactions of metalated 1-alkyl(aryl)-5-alkylsulfonyltetrazoles with electrophilic reagents as a general and highly stereoselective method for the preparation of functionally substituted olefins. 相似文献
9.
10.
We propose a concept for constructing a thermal imaging system of a new type that is based on unique magnetic properties of
high-temperature superconductors and on a noncontact magnetooptic information reading from a matrix sensing element. 相似文献