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Lebedyeva I.O.,Kharkiv Polytechnic Institute | Povstyanoy M.V.,Kharkiv Polytechnic Institute | Povstyanoy V.M.,Kharkiv Polytechnic Institute | Panasyuk O.G.,Ukrainian State University of Chemical Technology | And 2 more authors.
Monatshefte fur Chemie | Year: 2010

A one-pot synthesis of diethyl 4,4′-(1,4-phenylene)bis[6- (chloromethyl)-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylates] is proposed via three-component condensation of terephthalic aldehyde, 4-chloroacetoacetic ester, and ureas under Biginelli reaction conditions. Interaction of the obtained precursors that contain two highly reactive binucleophilic groups with primary amines leads to bis-heterocyclization with formation of (1,4-phenylene)-bis(pyrrolo[3,4-d]pyrimidine-2,5-diones). © Springer-Verlag 2010. Source


Lebedyeva I.O.,Kharkiv Polytechnic Institute | Povstyanoy V.M.,Kharkiv Polytechnic Institute | Ryabitskii A.B.,Spoluka Chemical Company | Panasyuk O.,Ukrainian State University of Chemical Technology | And 5 more authors.
European Journal of Organic Chemistry | Year: 2013

Polyheterocyclic pyrimidinyltheophyllines have been synthesized from pyrimidine and theophylline precursors. Attempts to cyclize these reactive bis-heterocyclic systems resulted in the formation of the corresponding diazepine moieties. In addition, modification of the reaction conditions led to the formation of imidazo[2,1-f]purines. Polyheterocyclic pyrimidinyltheophyllines have been synthesized from pyrimidine and theophylline precursors. Attempts to cyclize these reactive bis-heterocyclic systems resulted in the formation of the diazepine moiety. Modification of the reaction conditions led to the formation of imidazo[2,1-f]purines. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Rozhanchuk T.S.,Taras Shevchenko National University | Tananaiko O.Yu.,Taras Shevchenko National University | Mazurenko E.A.,Taras Shevchenko National University | Egorov O.A.,Spoluka Chemical Company
Journal of Analytical Chemistry | Year: 2012

The analytical prospects of a carbositall electrode modified with a film based on SiO 2, hemoglobin (Hb), and gold nanoparticles (CSE SiO 2-Hb-Au), prepared by deposition with an electrically generated catalyst, are reported. Hemoglobin on the surface of CSE SiO 2-Hb-Au is shown to possess electrocatalytic activity toward dissolved oxygen, giving a rationale for the development of a rapid voltammetric procedure of O 2 quantification with a detection limit of 0.1 mg/L. The inhibition activity of a number of nitrogen-containing organic substances to the catalytic current CSE SiO 2-Hb-Au is studied. A voltammetric procedure is proposed for determination of the anti-flu drug rimantadine, 1-(1-adamantyl)ethylamine hydrochloride, with a detection limit of 0.4 mg/L. The procedure is applicable to the quantification of rimantadine in blood serum and saliva. © 2012 Pleiades Publishing, Ltd. Source


Bricks J.,Ukrainian Academy of Sciences | Ryabitskii A.,Ukrainian Academy of Sciences | Ryabitskii A.,Spoluka Chemical Company | Kachkovskii A.,Ukrainian Academy of Sciences
Chemistry - A European Journal | Year: 2010

We report here the synthesis of a series of symmetrical and unsymmetrical trimethine cyanine dyes derived from 2-azaazulene, combined spectral and quantum-chemical investigations of their molecular geometry and electron structure, as well as the nature of the lowest electron transitions. Based on the analysis of both calculations and experimental data obtained from absorption and 13C NMR spectra, it was concluded that the 2-azaazulene residue can be treated as a weakly basic terminal group; its donor properties are provided with the participation of the HOMO-1, in contrast to the typical Brooker's terminal residues with their donor HOMOs. The new classification of the terminal groups of cyanine dyes, and hence the classification of types of unsymmetrical cyanines, is proposed. It is shown that the nature of the higher electron transitions (delocalized or local) in the cyanine dyes depends on their type. In the unsymmetrical trimethine cyanine of the mixed type, negative deviations are observed in their absorption spectra. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Lebedyeva I.O.,Kharkiv Polytechnic Institute | Povstyanoy M.V.,Kharkiv Polytechnic Institute | Ryabitskii A.B.,Spoluka Chemical Company | Povstyanoy V.M.,Kharkiv Polytechnic Institute
Journal of Heterocyclic Chemistry | Year: 2010

(Chemical Equation Presented) At the process of ethyl 6-methyl-4-aryl-2- thioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylates condensation with aryl aldehydes and chloroacetic acid the unexpected formation of 5- arylidenethiazolidine-2,4-diones was determined in high yields as the reaction time was increased to 20 h. The latter represent the products of destructive hydrolyzes of ethyl 2-benzylidene-7-methyl-3-oxo-5-aryl-2,3-dihydro-5H-[1,3] thiazolo[3,2-a]pyrimidine-6-carboxylates which have been proved by independent synthesis. © 2010 HeteroCorporation. Source

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