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1.
Previously unknown E isomers of azomethines (Schiff bases) were synthesized from vanillal and vanillin esters by their reaction with cyclohexylamine. 相似文献
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3.
2-(N-cytisinyl)acetamide or 3-(N-cytisinyl)propanamide were prepared by treatment of the methyl esters of N-cytisinylacetic or 3-(N-cytisinyl)propanoic acids with aqueous NH4OH. N-(2-Aminoethyl)-or N-(3-aminopropyl)cytisine was synthesized by reduction of the amide with (i-Bu)2AlH. 相似文献
4.
A. P. Avdeenko V. V. Pirozhenko S. A. Konovalov D. A. Roman’kov G. V. Palamarchuk O. V. Shishkinc 《Russian Journal of Organic Chemistry》2009,45(3):408-416
Reactions of thiocyanate ion with N-aroyl-, N-arylsulfonyl-, and N-(N-arylsulfonylbenzimidoyl)-1,4-benzoquinone imines follow the 1,4-addition pattern, and the adducts undergo intramolecular cyclization to give the corresponding N-substituted 5-amino-1,3-benzoxathiol-2-ones as final products. 相似文献
5.
L. A. Shemchuk V. P. Chernykh P. S. Arzumanov D. V. Levashov L. M. Shemchuk 《Russian Journal of Organic Chemistry》2007,43(4):615-618
The reaction of anthranilic acid hydrazide with diethyl oxalate under microwave irradiation was accompanied by decarboxylation with formation of 3-amino-3,4-dihydroquinazolin-4-one, and acylation of the latter with succinic anhydride gave N-(4-oxo-3,4-dihydroquinazolin-3-yl)siccinimide which was converted into various N-(4-oxo-3,4-dihydroquinazolin-3-yl)succinamic acid derivatives. 相似文献
6.
A. V. Lezov G. E. Polushina A. A. Lezov P. S. Vlasov N. S. Domnina 《Polymer Science Series A》2011,53(2):93-101
The hydrodynamic and conformational properties of molecules of poly(N,N-diallyl-N,N-dimethylammonium chloride) and N,N-diallyl-N,N-dimethylammonium chloride-maleic acid copolymers of different compositions in solutions with various ionic-strength and pH
values, as well as of the polyelectrolyte complex based on the copolymer with dodecyl sulfate anions in chloroform, are studied.
For poly(N,N-diallyl-N,N-dimethylammonium chloride) molecules in a 1 M NaCl solution, the Kuhn segment length and the hydrodynamic diameter of the
chain are estimated as A = 3.9 nm and d = 0.48 nm, respectively. In acidic solutions with pH 3.5, the copolymers demonstrate behavior typical for polyelectrolytes.
In an alkaline solution with pH 13, when 1 M NaCl is added to the solution of the copolymer containing 29 mol % maleic acid
units, there is an antipolyelectrolyte effect that manifests itself as an increase in the intrinsic viscosity of the copolymer
and in the hydrodynamic radius of its molecules. It is found that an increase in the fraction of maleic acid units in the
copolymer from 12 to 42 mol % brings about a reduction in the equilibrium rigidity of its macromolecules from 4.1 to 2.2 nm.
The equilibrium rigidity of polyelectrolyte-complex molecules is higher than that of initial copolymer molecules owing to
steric interactions arising between the aliphatic chains of dodecyl sulfate anions. In an electric field, the molecules of
the complex are oriented owing to the induced dipole moment resulting from the displacement of dodecyl sulfate anions along
the chain contour. 相似文献
7.
A. I. Vorob’eva M. S. Babaev L. V. Spirikhin N. M. Shishlov S. V. Kolesov 《Russian Journal of Applied Chemistry》2016,89(1):160-164
A copolymer of N,N-diallyl-N,N-dimethylammonium chloride with maleic acid of constant composition was prepared under the conditions of radical initiation. The possibility of the functionalization of the copolymer with drugs containing amino groups by polymer-analogous transformations was examined. Conditions were found for preparing conjugates of the copolymer with isoniazid. The structures and the quantitative compositions of the conjugates were determined by 13С NMR spectroscopy, and the possibility of preparing conjugates with controlled drug content was demonstrated. 相似文献
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9.
O. G. Strukov V. B. Kondrat’ev Z. V. Vlasova V. A. Petrunin 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2017,91(1):100-105
Conformers of the biologically active compounds CH3P(O)(OR)(SCH2CH2NR 2 ′ ), where (I) R = i-C4H9, R′ = C2H5 and (II) R = C2H5, R′ = i-C3H7, are calculated within the AM1 level of theory. The elongated and twisted forms with maximum and minimum distances between a nitrogen atom and those of a phosphorus tetrahedron, respectively, and bearing a syn and anti oriented alkoxy group relative to a phosphoryl oxygen, are studied. It is found that the differences between the energy, electronic, and geometric parameters of these forms are apparent in differences between their properties, e.g., the ability to participate in complexation and protonation, reactions that to some extent simulate the interaction between a substance and a biological object. 相似文献
10.
A series of N-(naphthalen-1-yl)-N-(phenyl(quinolin-3-yl)methyl)amide derivatives were designed and synthesized as anti-Mycobacterium tuberculosis drugs. NMR
spectra showed that two conformational isomers of these compounds exist in solution, which is not due to cis-trans isomerization of amide bond. We proposed that the spatial interactions between three large aromatic groups caused the conformational
isomerization, which was supported by molecular modeling and X-ray diffraction. 相似文献
11.
U. S. Makhmudov Sh. B. Rakhimov B. Tashkhodzhaev M. G. Levkovich V. I. Vinogradova 《Chemistry of Natural Compounds》2008,44(2):208-212
The molecular structures of N-(o-and p-hydroxybenzyl)cytisine were investigated by NMR spectroscopy, x-ray structure analysis, and molecular modeling. It was found
that NMR resonances of the OH and aromatic protons in N-(o-hydroxybenzyl)cytisine were doubled because of the presence of two conformers in solution.
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Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 165–168, March–April, 2008. 相似文献
12.
N. A. Likhacheva A. A. Fatykhov I. B. Abdrakhmanov R. R. Gataullin 《Russian Journal of Organic Chemistry》2007,43(9):1305-1309
Hydroxymercuration-demercuration of N-p-tolysulfonyl-4,4a,9,9a-tetrahydro-3H-carbazoles and N-p-tolyl(or methyl)sulfonyl-1,3a,4,8b-tetrahydrocyclopenta[b]indoles leads to the formation of the corresponding N-p-tolylsulfonyl-2,3,4,4a,9,9a-hexahydro-1H-carbazol-2-ols and N-p-tolyl(or methyl)sulfonyl-1,2,3,3a,4,8b-hexahydrocyclopenta[b]indol-2-ols. The latter are oxidized to 2-oxo derivatives with potassium dichromate. The oxidation of 2-methoxy-8-methyl-N-p-tolylsulfonyl-2,3,4,4a,9,9a-hexahydro-1H-carbazol-1-ol under analogous conditions gives 2-methoxy-8-methyl-N-p-tolysulfonyl-2,3,4,4a,9,9a-hexahydro-1H-carbazol-1-one. 相似文献
13.
V. V. Semenov S. A. Shevelev A. B. Bruskin M. I. Kanishchev A. T. Baryshnikov 《Russian Chemical Bulletin》2009,58(10):2077-2096
A general synthetic procedure for the synthesis of N-dinitromethyl derivatives of nitrogen-containing heterocycles has been developed. The procedure includes the destructive
nitration of heterocyclic N-acetonyl derivatives of tetrazoles, 1,2,4- and 1,2,3-triazoles, pyrazoles, imidazoles and their bicyclic analogs, as well
as imides of carboxylic and sulfonic acids and substituted hydrazines with mixtures of sulfuric and nitric acids. The kinetic
study of the reaction mechanism was performed using UV and NMR spectroscopy. It was found that the NO2 groups were sequentially introduced into the methylene fragment by the addition of the nitronium ion to multiple bonds of
intermediate enols followed by hydrolysis of the acetyl moiety. The rate and direction of the enolization (due to the CH2 and CH3 groups) of the N-acetonyl compounds in sulfuric acid solutions were determined by the study of the deuterium exchange kinetics. The synthesis
of the N-dinitromethyl compounds is complicated by side reactions, such as the decomposition of intermediate α-nitroketone, the nitration
of the methyl group in the acetonyl moiety, and the nitration of the dinitromethyl products to trinitromethyl derivatives. 相似文献
14.
Preparation method was developed for N-(2,2-dichlorovinyl)-N-alkylarenesulfonamides based on dehydrochlorination of the corresponding N-(2,2,2-trichloroethyl)-N-alkylarenesulfonamides. 相似文献
15.
T. F. Ibragimov M. G. Levkovich V. A. Saprykina Kh. M. Shakhidoyatov 《Chemistry of Natural Compounds》2010,46(5):767-770
N-Chloroacetylcytisine was synthesized by acylation of (–)-cytisine. Stable Z- and E-conformers with respect to rotational isomerism around the N-12–CO bond were found in PMR spectra at room temperature. The
point at which PMR resonances of the Z- and E-conformers coalesced upon heating was measured. The transition barrier between the conformers was estimated. 相似文献
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17.
L. A. Baltina A. I. Fairushina L. A. Baltina 《Russian Journal of General Chemistry》2015,85(12):2735-2738
Synthesis of amino acid conjugates of glycyrrhizic acid with the use of N-hydroxyphthalimide, N,N'-dicyclohexylcarbodiimide, and tert-butyl esters of L-amino acids (valine, isoleucine, phenylalanine, and methionine) was performed followed by deprotection with trifluoroacetic acid. The target amino acid conjugates were isolated by column chromatography on silica gel in 40–45% yield. The structure of the prepared compounds was confirmed by IR and 13C NMR spectroscopy. 相似文献
18.
Reactions of acetamide and benzamide with N-allyltrifluoromethanesulfonamide in the presence of t-BuOCl–NaI afforded exclusively 2,5-bis(chloromethyl)-1,4-bis(trifluoromethanesulfonyl)piperazine. Analogous reaction with N,N-diallyltrifluoromethanesulfonamide gave mixed halogenation product at only one C=C double bond of the substrate. 相似文献
19.
I. E. Efremova M. I. Vakulenko K. A. Lysenko I. S. Bushmarinov L. V. Lapshina G. A. Berkova V. M. Berestovitskaya 《Russian Journal of General Chemistry》2010,80(11):2298-2305
A modification of 1-nitrocyclohexene synthesis is proposed; its reaction with phenylhydrazine and benzoic acid hydrazide is
shown to afford monoadducts, and with hydrazine hydrate, bisaduct. With diphenylguanidine occurs heterocyclization to 1-phenyl-2-N-phenylamino-4,5,6,7-tetrahydrobenzimidazole, whose structure is confirmed by the X-ray diffraction data. The analysis performed
for this compound of the electron density distribution function in the crystal made it possible to estimate the charge distribution,
π-electrons delocalization nature, and the role of N-H…N, C-H…H-C and C-H…C interactions in the formation of the crystal packing. 相似文献
20.
M. S. Klenov A. M. Churakov O. V. Anikin Yu. A. Strelenko V. A. Tartakovsky 《Russian Chemical Bulletin》2009,58(10):2047-2057
Salts of N-nitro-O-(4-nitrophenyl)hydroxylamine were synthesized by a new method of oxidative nitration, involving the reaction of O-(4-nitrophenyl)hydroxylamine with KNO2 or NaNO2 in the presence of PhI(OAc)2 or PhIO as oxidants. When using Na15NO2, the samples containing the nitro group labeled with the 15N isotope were obtained. Acidification of the appropriate salt gave N-nitro-O-(4-nitrophenyl)hydroxylamine. It is the first N-nitrohydroxylamine isolated in the H-form. Its thermal stability was investigated and the probable mechanism of decomposition
was suggested. From a comparison of the 14N and 15N NMR spectra of N-nitro-O-(4-nitrophenyl)hydroxylamine with those of its O- and N-methylated derivatives, its equilibrium with the aci-form (N=NOOH) was inferred. 相似文献