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71.
Deev SL Shenkarev ZO Shestakova TS Chupakhin ON Rusinov VL Arseniev AS 《The Journal of organic chemistry》2010,75(24):8487-8497
Two general methods for the selective incorporation of an (15)N-label in the azole ring of tetrazolo[1,5-b][1,2,4]triazines and tetrazolo[1,5-a]pyrimidines were developed. The first approach included treatment of azinylhydrazides with (15)N-labeled nitrous acid, and the second approach was based on fusion of the azine ring to [2-(15)N]-5-aminotetrazole. The synthesized compounds were studied by (1)H, (13)C, and (15)N NMR spectroscopy in both DMSO and TFA solution, in which the azide-tetrazole equilibrium is shifted to tetrazole and azide forms, respectively. Incorporation of the (15)N-label led to the appearance of (13)C-(15)N J coupling constants (J(CN)), which can be measured easily using either 1D (13)C spectra with selective (15)N decoupling or with amplitude modulated 1D (13)C spin-echo experiments with selective inversion of the (15)N nuclei. The observed J(CN) patterns permit unambiguous determination of the type of fusion between the azole and azine rings in tetrazolo[1,5-b][1,2,4]triazine derivatives. Joint analysis of J(CN) patterns and (15)N chemical shifts was found to be the most efficient way to study the azido-tetrazole equilibrium. 相似文献
72.
Pavel Arsenyan Kira Rubina Irina Shestakova Edgars Abele Ramona Abele Ilona Domracheva Alena Nesterova Juris Popelis Edmunds Lukevics 《应用有机金属化学》2003,17(11):825-830
New hydroselenites of the different silylalkylthio‐substituted N‐heterocycles have been prepared by the reaction of selenium dioxide with N‐heterocycles in an aqueous medium. Their structure was confirmed by 1H, 13C, and 77Se NMR data. Most of these silylalkylthio‐substituted N‐heterocycles and their hydroselenites have an expressed cytotoxic activity on the MG‐22A (mouse hepatoma), HT‐1080 (human fibrosarcoma), B16 (mouse melanoma), and Neuro 2A (mouse neuroblastoma) cell lines. Some of the hydroselenites exhibit free‐radical protection simultaneously with a high cytotoxic effect. The substances studied were also active in vivoagainst sarcoma S‐180. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
73.
I. A. Khalymbadzha T. S. Shestakova S. L. Deev V. L. Rusinov O. N. Chupakhin Z. O. Shenkarev A. S. Arseniev 《Russian Chemical Bulletin》2013,62(2):521-528
A new method was developed for the investigation of an azido-tetrazole equilibrium based on using a complex analysis of 13C-15N and 1H-15N spin-spin coupling constants. The use of this approach became possible due to the selective inclusion of 15N isotopes into the structures of 2-azidopyrimidines and their cyclic analogs tetrazolo[1,5-a]pyrimidines. 相似文献
74.
75.
Chebotarev A. N. Shestakova M. V. Rusanov E. B. 《Russian Journal of Coordination Chemistry》2002,28(8):601-602
Russian Journal of Coordination Chemistry - 相似文献
76.
M. A. Shestakova 《Journal of Mathematical Sciences》2011,177(4):638-645
A classification of six-dimensional webs H
s
by type of the associated Lie algebra is carried out. Two approaches to the investigation of geometry of nontrivial class
of webs H
s
are considered. 相似文献
77.
G. P. Shestakova 《Journal of Mathematical Sciences》1981,17(4):2076-2079
The problem is solved of the homologlcal determinacy of modules with torsion over rings with a power basis.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova, Vol. 86, pp. 180–184, 1979. 相似文献
78.
79.
80.
Tatyana A. Stroganova Vladimir K. Vasilin Polina S. Shestakova Viktor M. Red'kin Gennady D. Krapivin 《Journal of heterocyclic chemistry》2015,52(1):227-234
3‐Acylaminofuro[2,3‐b]pyridine derivatives have been synthesized, and their behavior under acidic and basic conditions was studied. A new base‐catalyzed rearrangement of 3‐acylaminofuro[2,3‐b]pyridine derivatives into 3‐(oxazol‐4‐yl)pyridine‐2‐ones has been founded. 相似文献