T 82 Transformations of 5-diazo derivatives of 1,3-dimethyl-6-hydrazinouracil - new synthetic approaches to novel pyrimidine-derivatives [Electronic resource] / Y. A. Azev, O. L. Guselnikova, O. N. Chupakhin // Mendeleev Communications. - 1994. - N 6. - P208-209 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: 1,3-Dimethyl-6-hydrazinouracil 1 gives hydrazones 2 with the corresponding aldehydes. Heating of 6-hydrazinouracil 1 in ethanol in the presence of hyrochloric acid results in the formation of N1, N2-bis(1,3-dimethyl-2,6-dioxopyrimid-4-yl)hydrazine 3, which gives the diazo derivative 4 on treatment with 2,4-diazido-6-cyanomethoxy-s-triazine in DMSO in the presence of triethylamine et room temperature |
H 99 Interaction of perfluorent-2-ene and its 2-amino-4-ivino derivative with ethylenediamine and with diethylenetriamine [Text] / V. I. Saloutin, Z. E. Skryabina, Ya. V. Burgart, O. N. Chupakhin, M. Fontaltaba, X. Solans, M. Fontbardia // Journal of Fluorine Chemistry. - 1994. - Vol. 69, N 1. - P25-29 Рубрики: ХИМИЧЕСКИЕ НАУКИ |
A 18 Acidic hydrolysis of N-acyl-1-substituted 3-amino-1,2-dicarba-closo-dodecaboranes [Electronic resource] / G. L. Levit, A. M. Demin, M. I. Kodess, M. A. Ezhikova, L. Sh. Sadretdinova, V. A. Ol'shevskaya, V. N. Kalinin, V. P. Krasnov, V. N. Charushin // Journal of Organometallic Chemistry. - 2005. - Vol. 690, № 11. - P2783-2786 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: Acidic hydrolysis of N-acyl 1-methyl- and 1-phenyl-3-amino-1,2-dicarba-closo-dodecaboranes has been studied. It has been shown that acidic hydrolysis of diastereomeric amides of 1-methyl-3-amino-1,2-dicarba-closo-dodecaborane results in the partial racemization of the target 3-amino-1-methylcarborane. Under the similar conditions, the hydrolysis of N-acyl-3-amino-1-phenyl-1,2-dicarba-closo-dodecaboranes resulted in amide bond cleavage accompanied by simultaneous deboronation with the removal of boron atom at position 6 of carborane cage and formation of 7,8-dicarba-nido-undecaborane derivative according to 11B and 1H NMR spectroscopy. \\\\Expert2\\nbo\\Journal of Organometallic Chemistry\\2005, v. 690, p.2783.pdf |
M 46 Medvedeva, N. Study of rare encounters in a membrane using quenching of cascade reaction between triplet and photochrome probes with nitroxide radicals [Text] / N. Medvedeva, V. Papper, G. I. Likhtenshtein // Physical Chemistry Chemical Physics. - 2005. - Vol. 7, № 18. - P3368-3374. - Библиогр. : с. 3373 (26 назв.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: Measurements of active encounters between molecules in native membranes containing ingredients, including proteins, are of prime importance. To estimate rare encounters in a high range of rate constants (rate coefficients) and distances between interacting molecules in membranes, a cascade of photochemical reactions for molecules diffusing in multilamellar liposomes was investigated. The sensitised cascade triplet cis-trans photoisomerisation of the excited stilbene involves the use of a triplet sensitiser (Erythrosin B), a photochrome stilbene-derivative probe (4-dimethylamino-4 -aminostilbene) exhibiting the phenomenon of trans-cis photoisomerisation, and nitroxide radicals (5-doxyl stearic acid) to quench the excited triplet state of the sensitiser. Measurement of the phosphorescence lifetime of Erythrosin B and the fluorescence enhancement of the stilbene-derivative photochrome probe, at various concentrations of the nitroxide probe, made it possible to calculate the quenching rate constant kq= 1.1*10 15 cm2 M-1 s-1 and the rate constant of the triplet-triplet energy transfer between the sensitiser and stilbene probe kT= 1.0*1012 cm2 M-1 s-1. These values, together with the data on diffusion rate constant, obtained by methods utilising various theoretical characteristic times of about seven orders of magnitude and the experimental rate constants of about five orders of magnitude, were found to be in good agreement with the advanced theory of diffusion-controlled reactions in two dimensions. Because the characteristic time of the proposed cascade method is relatively large (0.1 s), it is possible to follow rare collisions between molecules and free radicals in model and biological membranes with a very sensitive fluorescence spectroscopy technique, using a relatively low concentration of probes. |
H 10 H-1 and C-13-NMR investigations on-adduct formation of 1,2,4-triazine 4-oxides and 3-chloro-6-phenyl-1,2,4-triazine with liquid ammonia and alkylamines [Text] / A. Rykowski, O. N. Chupakhin, D. N. Kozhevnikov, V. N. Kozhevnikov, V. L. Rusinov, der Plas H. C. Van // Heterocycles. - 2001. - Т. 55, № 1. - P127-133 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: 1H- and 13C-NMR spectra of the ?-adducts formed between 6-phenyl-1,2,4-triazine 4-oxide (1a), 3-ethyl-6-phenyl-1,2,4-triazine 4-oxide (1b) and liquid ammonia, methylamine or dimethylamine are described, together with 1H NMR spectra of 3-chloro-6-phenyl-1,2,4-triazine (7) in liquid ammonia. The results of the NMR study have shown that the carbon C-5 in 1a-b and 7 is the preferred site for nucleophilic attack by liquid ammonia and alkylamines at low temperatures (from -75° to -20°C). The ?-adduct (5e) formed between 1a and dimethylamine at -75°C on heating to -20°C irreversibly converts to open-chain product (3a), via intermediary C-3 ?-adduct (6). The amination of 7 into 3-amino-6-phenyl-1,2,4-triazine (10) occurs via SN(AE) mechanism involving the isomerisation of the C-5 ?-adduct (8) into the C-3 ?-adduct (9) as confirmed by a 15N study with labeled liquid ammonia. |
A 10 A simple one pot synthesis of condensed 1,2,4-triazines by using the tandem AN-SNipso and SNH-SNipso reactions [Text] / O. N. Chupakhin, G. L. Rusinov, D. G. Beresnev, V. N. Charushin, H. Neunhoeffer // Journal of Heterocyclic Chemistry. - 2001. - Т. 38, № 4. - P901-907 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: A new synthetic approach to condensed 1,2,4-triazines based on using the tandem AN-SNipso and SNH-SNipso reactions has been developed. 5-Methoxy-3-penyl-l,2,4 1,2,4-triazine and its N1-methyl quaternary salt were found to react with C,N-, C,O- and N,N?-bifunctional nucleophiles (m-phenylenediamine, resorcinol, semicarbazide and ureas) into triazacarbazoles, benzofuro[2,3-e][1,2,4]-triazines, and 6-azapurine derivatives. In all cases nucleophiles attack first the unsubstituted C-6 carbon of the triazine ring, while the final stage is replacement of the methoxy group affording cyclization products. \\\\Cserver\\dist\\НБО\\Электронная библиотека_Библиогр1\\Journal of Heterocyclic Chemistry\\2001.v.38.p.901.Chupachin.pdf |
M 78 Modification of macrocyclic compounds by azaheterocycles [Text] / N. A. Itsikson, G. L. Rusinov, D. G. Beresnev, O. N. Chupakhin // Heterocycles. - 2003. - Vol. 61, № 31. - P593-637 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: Synthesis, modification and properties of macrocycles, such as crown ethers, their open-chain analogues, i.e. podands, calixarenes and resorcinarenes, having azaheterocyclic fragment are discussed.???? |
E 27 Efficient large (ca. 40 g) laboratory scale preparation of (S)- and (R)-valine tert-butyl esters [Text] / V. P. Krasnov, G. L. Levit, I. M. Bukrina, A. M. Demin, O. N. Chupakhin, Ji Uk Yoo // Tetrahedron: Asymmetry . - 2002. - Vol. 13, № 17. - P1911-1914 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: A large laboratory scale (ca. 40 g) method for the preparation of enantiomerically pure (S)- and (R)-valine tert-butyl esters has been developed. The method involves three steps: preparation of N-TFA-valines, preparation of valine tert-butyl esters using 2-methylpropene in dioxane in the presence of sulfuric acid, and isolation of the target compounds as the acetate derivative. The overall yield is up to 70% relative to the starting valine, ee being more than 98% (by HPLC)???? |
T 44 The first case of direct coupling of heterocycles with calixarenes. Reaction of resorcinarenes with 1,2,4-triazin-5(2H)-ones [Text] / O. N. Chupakhin, G. L. Rusinov, N. A. Itsikson, D. G. Beresnev, I. L. Nikolaeva, A. R. Burilov, A. I. Konovalov // Heterocyclic Communications. - 2004. - Vol. 10, № 1. - P15-18 : ил. - Библиогр.: с. 18 (8 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): CALIXARENE -- CARBON -- RESORCINOL DERIVATIVE -- TRIAZINE DERIVATIVE Аннотация: A convenient method for an one-step coupling of resorcinarenes with 3-R-1,2,4-triazin-5(2H)-ones, involving nucleophilic addition to the unsubstituted carbon atom C-6 of triazine ring, has been worked out. |
M 57 Mercury sorption on a thiocarbamoyl derivative of chitosan [Text] / K. C. Gavilan, A. V. Pestov, H. M. Garcia, Yu. G. Yatluk, J. Roussy, E. Guibal // Journal of Hazardous Materials. - 2009. - Vol. 165, № 1-5. - P415-426 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: The grafting of thiourea on chitosan backbone allows synthesizing a thiocarbamoyl derivative that was very efficient for mercury sorption in acidic solutions. Though the sorption capacity is not increased compared to raw chitosan in near neutral solutions, this modification allowed maintaining high sorption capacity (close to 2.3 mmol Hg g-1) at pH 2. Mercury sorption in acidic solutions is not affected by the presence of competitor metals (such as Zn(II), Pb(II), Cu(II), Cd(II), Ni(II)) or the presence of nitrate anions (even at concentration as high as 0.8 M)). The presence of chloride or sulfate anions (0.8 M) decreased Hg(II) sorption capacity to 1 mmol Hg g-1. Kinetics are controlled by a combination of pseudo second-order reaction rate and resistance to intraparticle diffusion. Mercury desorption reached about 75% using thiourea (in HCl solution) \\\\Expert2\\nbo\\Journal of Hazardous Materials\\2009, v.165.p.415.pdf |
H 43 Heavy metals removal by flocculation/precipitation using N-(2-carboxyethyl)chitosans [Text] / S. YU. Bratskaya, A. V. Pestov, Yu. G. Yatluk, V. A. Avramenko // Colloids and Surfaces A: Physicochemical and Engineering Aspects. - 2009. - Vol. 339, № 1-3. - P140-144 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: Here we report on solution properties and flocculation performance of polyampholyte chitosan derivatives - N-carboxyethylated chitosans (CEC) - synthesized "in gel" by treatment of chitosan with acrylic acid. We show that carboxyethylation with the substitution degrees (DS) from 0.7 to 1.6 yields water-soluble derivatives, whose isoelectric points (IEP) range from 6.30 to 3.55. At pH 7.5 interaction of negatively charged CEC derivatives with positively charged colloids of the heavy metal hydroxides (Zn2+, Cu2+, Ni2+), serving as a model of postgalvanic wastewaters, results in lowering of electrokinetic potential of the hydroxide colloids and their precipitation at appropriate flocculant dose. Investigations of CEC flocculation performance depending on pH and DS show that the efficiency of metal removal decreases in the row Cu2+ Zn2+ Ni2+ corresponding to the row of the hydroxocomplex stability for these metals. The higher was pH of the system and DS of CEC derivative, the narrower was the flocculation window and the stronger was negative effect of flocculant overdosing on the efficiency of heavy metal removal. Based on the estimation of floc settling rates and the residual metal concentrations, we have concluded that the optimal DS of CEC derivatives for the precipitation of metal hydroxides is 0.7-1.0 |
S 10 S-N(H) approach in the synthesis of nitronyl nitroxides [Text] / O. N. Chupakhin, I. A. Utepova, M. V. Varaksin, E. V. Tretyakov, G. V. Romanenko, V. Ovcharenko, D. V. Stass // Journal of Organic Chemistry. - 2009. - Vol. 74, № 7. - P2870-2872 Рубрики: ХИМИЧЕСКИЕ НАУКИ \\\\Expert2\\nbo\\Journal of Organic Chemistry\\2009, v.74, p.2870.pdf |
A 48 Aminomethylation of chlorophyll a derivatives using bis(N,N-dimethylamino) methane [Text] / D. V. Belykh, I. S. Tarabukina, D. A. Gruzdev, M. I. Kodess, A. V. Kutchin // Journal of Porphyrins and Phthalocyanines. - 2009. - Vol. 13, № 7-8. - P949-956 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: Bis(N,N-dimethylamino)methane has been shown to be a convenient reagent for the aminomethylation of chlorophyll a derivatives. Methylpheophorbide a (in enol form) and chlorin e6 13-amides were aminomethylated with bis(N,N-dimethylamino)methane. Reactivity of methylpheophorbide a exo-ring and chlorin e6 13-amides vinyl group were shown to be different. Selective methylpheophorbide a exo-ring aminomethylation was realized and isomerization of the exo-ring aminomethylation product with rhodochlorin 15-acrylic derivative formation was studied. The action of bis(N,N- dimethylamino)-methane in the presence of weak acid has been shown to be a simple and effective synthetic procedure to obtain a new chlorin e6 derivative with two N,N-dimethylaminomethyl substituents in the vinyl group. The aminomethylation products' high yields, the simplicity of the procedure, the use of metal-free chlorines and the possible synthesis of new compounds, were found to be the main advantages of using bis(N,N-dimethylamino)methane as an aminomethylation reagent in chlorophyll a derivatives' chemistry |
U 62 Unusual transformation of a fluoroalkyl-containing beta-aminovinyl ketone [Electronic resource] / O. P. Krasnykh, N. S. Karpenko, V. I. Filyakova, V. N. Charushin // Russian Chemical Bulletin (Translation of Izvestiya Akademii Nauk, Seriya Khimicheskaya). - 2004. - Vol. 53, № 6. - P1355-1356 : ил. - Библиогр.: с. 1356 (3 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): CHLORIDE -- KETONE DERIVATIVE -- CYCLIZATION -- FLUOROALKYL-CONTAINING BETA-AMINOVINYL KETONE \\\\Expert2\\nbo\\Russian Chemical Bulletin\\2004, 53 (6), 1355.pdf |
R 30 Reactions of 2-Arylhydrazono-1,3-dicarbonyl Compounds with Ethylenediamine [Electronic resource] / O. G. Khudina, Ya. V. Burgart, N. V. Murashova, V. I. Saloutin // Russian Journal of Organic Chemistry (Translation of Zhurnal Organicheskoi Khimii). - 2003. - Vol. 39, № 10. - P1421-1428 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: 2-Arylhydrazono-1,3-diketones react with ethylenediamine to give, depending on the substituents, dihydro-1,4-diazepine derivative or N,N'-ethylenebis(1,3-aminovinyl ketones). Treatment of the latter with nickel(II) or copper(II) acetate results in formation of the corresponding metal chelates. Nickel complexes of N,N'-ethylenebis(1,3-aminovinyl ketones) can also be synthesized from 2-arylhydrazono-1,3-diketones and ethylenediamine on a metal template. Reactions of 2-arylhydrazono-3-oxo esters with ethylenediamine yield N,N'-ethylenebis(3-alkyl-2-arylhydrazono-3-oxopropionamides). Ethyl 2-arylhydrazonoacetoacetate reacts with ethylenediamine under mild conditions, affording ethyl 2-p-tolylazo-3-[2-(2-p-tolylhydrazono-1,3-dioxobutylamino)ethylamino]-2-butenoate?? \\\\Expert2\\nbo\\Russian Journal of Organic Chemistry\\2003, 39 (10), 1421.pdf |
F 76 Formation of polynuclear palladium complexes with the benzimidazole-2-thiolate anion [Electronic resource] / M. O. Talismanova, A. A. Sidorov, G. G. Aleksandrov, V. N. Charushin, S. K. Kotovskaya, I. L. Eremenko, I. I. Moiseeva // Russian Chemical Bulletin (Translation of Izvestiya Akademii Nauk, Seriya Khimicheskaya). - 2008. - Vol. 57, № 1. - P47-55 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: The reactions of palladium(II) salts with 2-mercaptobenzimidazole (HL) and its 5,6-difluorinated derivative (HLF) were investigated. In the presence of hydrochloric acid, PdCl2 and K2PdCl4 react with HL and HLF in the ethanol—water and acetonitrile—water systems to form the mono-nuclear dicationic complexes [Pd(HL)4]Cl2 (1) and [Pd(LF)4]Cl2 (2). In the absence of HCl, the reactions afford the tetranuclear complex Pd4[(L)2(3-S,N-(L))2(S,N-(L))4] (3). The reaction of triethylamine with an ethanolic solution of 3 leads to degradation of 3 and the formation of the lantern-type dinuclear complex Pd2[2-(L)4] (4), in which the palladium atoms are in the nonequivalent coordination environment, PdN4 and PdS4. The reaction of K2PdCl4 with HL or HLF in the THF—water or acetonitrile—water systems (for the reaction with HLF) in the presence of Et3N produces the lantern-type dinuclear complexes Pd2[(?S,N-(L3))4] and Pd2[(S,N)(LF))4] (5), in which the metal atoms are in the equivalent coordination environment (cis-PdN2S2) \\\\Expert2\\nbo\\Russian Chemical Bulletin\\2008, 57 (1), 47.pdf |
S 98 Synthesis of perfluoro- and 2-trifluoromethylpentafluoro-dihydrofurans and their epoxy derivatives [Electronic resource] / V. I. Filyakova, M. I. Kodess, A. Ya. Zapevalov, V. I. Saloutin // Russian Journal of Organic Chemistry (Translation of Zhurnal Organicheskoi Khimii). - 2003. - Vol. 39, № 7. - P1010-1015. - Bibliogr. : p. 1015 (11 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): CESIUM -- EPOXIDE -- FURAN DERIVATIVE -- PERFLUORO COMPOUND Аннотация: Perfluorotetrahydrofuran-2-carboxylic acid was converted through a series of transformations into perfluoro-2,3-dihydrofuran and perfluoro-2,5- dihydrofuran; likewise, from (2-perfluorotetrahydrofuryl)difluoroacetic acid 2-trifluoromethylpentafluoro-2,3-dihydrofuran was obtained. Perfluoro-2,3- dihydrofuran and 2-trifluoromethylpentafluoro-2,3-dihydrofuran underwent isomerization into perfluoro-2,5-dihydrofuran and 2-trifluoromethylpentafluoro- 2,5-dihydrofuran by the action of cesium fluoride. Treatment of perfluoro-2,5-dihydrofuran with SbF5 resulted in ring opening and formation of cis-perfluoro-2-butenoyl fluoride, while 2- trifluoromethylpentafluoro-2,3-dihydrofuran was converted into 2-trifluoromethylpentafluoro-2,5-dihydrofuran under the same conditions. Perfluoro-3,4-epoxytetrahydrofuran and 2-trifluoromethyl-3,4-epoxypenta- fluorotetrahydrofuran containing fused oxirane and tetrahydrofuran rings were synthesized by reactions of perfluoro-2,5-dihydrofuran and 2- trifluoromethylpentafluoro-2,5-dihydrofuran, respectively, with sodium hypochlorite. \\\\Expert2\\nbo\\Russian Journal of Organic Chemistry\\2003, 39 (7), 1010.pdf |
R 30 Reaction of polyfluoro-3-chloro(bromo)-1-butenes with sodium hypohalites and properties of epoxides derived therefrom [Electronic resource] / A. Ya. Zapevalov, V. I. Filyakova, M. I. Kodess, V. I. Saloutin // Russian Journal of Organic Chemistry (Translation of Zhurnal Organicheskoi Khimii). - 2003. - Vol. 39, № 7. - P919-923. - Bibliogr. : p. 923 (13 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): DERIVATIVE -- CARBON -- CESIUM -- EPOXIDE -- HYPOHALITES -- SODIUM HYPOHALITES Аннотация: Epoxidation of 3-chloro(bromo)heptafluoro-1-butenes and 3,4-dichlorohexafluoro-1-butene with aqueous solutions of sodium hypohalites is accompanied by cleavage of the carbon skeleton at the double bond and formation of polyfluorocarboxylic acid sodium salts as by-products. 3-Chloro(bromo)-1,2- epoxyheptafluoro- and 3,4-dichloro-1,2-epoxyhexafluorobutanes were synthesized and subjected to isomerization into carbonyl compounds by the action of cesium fluoride or antimony pentafluoride. \\\\Expert2\\nbo\\Russian Journal of Organic Chemistry\\2003, 39 (7), 919.pdf |
Z 99 [1,5]Sigmatropic shift of hydrogen in amination of 3-pyrrolidino-1,2,4- triazine 4-oxide [Text] / O. N. Chupakhin, V. N. Kozhevnikov, D. N. Kozhevnikov, V. L. Rusinov // Tetrahedron Letters. - 1999. - Vol. 40, № 33. - P6099-6100. - Bibliogr. : p. 6100 (11 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): AMINATION -- DERIVATIVE -- PYRROLIDINE DERIVATIVE -- TRIAZINE DERIVATIVE Аннотация: The reaction of 3-pyrrolidino-1,2,4-triazine 4-oxide with ammonia leads to the product of tele-substitution of pyrrolidine - 5-amino-1,2,4-triazine 4-oxide. Sigmatropic shift of hydrogen postulated for such reactions has been proved by isolation of key intermediates. |
C 52 Chiroptical properties and new derivatives of cyclopalladated 6-ferrocenyl-2,2-bipyridine. Molecular structure of a tert-butyl isocyanide derivative [Electronic resource] / L. A. Bulygina, Z. A. Starikova, K. K. Babievskii, I. A. Utepova, V. L. Rusinov, O. N. Chupakhin, V. I. Sokolov // Russian Chemical Bulletin (Translation of Izvestiya Akademii Nauk, Seriya Khimicheskaya). - 2008. - Vol. 57, № 10. - P2214-2216 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: Optically active cyclopalladated 6-ferrocenyl-2,2?-bipyridine has been studied by circular dichroism and luminescent spectroscopy; a replacement of the chloride ion at palladium with the rhodanide ion and tert-butyl isocyanide molecule has been carried out; molecular structure of the product in the latter case has been determined by X-ray diffraction analysis \\\\Expert2\\nbo\\Russian Chemical Bulletin\\2008, 57 (10), 2214-2216.pdf |