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Klasek A.,Tomas Bata University in Zlin | Rudolf O.,Tomas Bata University in Zlin | Rouchal M.,Tomas Bata University in Zlin | Lycka A.,Research Institute for Organic Syntheses VUOS | Ruzicka A.,University of Pardubice
Tetrahedron | Year: 2013

4-Hydroxy-2-quinolones (1) react with thionyl chloride to give new spiro-benzo[1,3]oxathioles (3) and bis(4-hydroxy-2-quinolone-3-yl)sulfides (2) and small quantities of 3-chloro-4-hydroxyquinolin-2-ones (4). Compounds 3 afford sulfides 2 by heating in different solvents and [1,4]oxathiino[3,2-c:5,6- c′]diquinoline- 6,8(5H,9H)-diones (6) by reaction with triphenylphosphine. The reconversion of compounds 2 to 3 was achieved using bromine. The reaction mechanisms are discussed for all transformations. All compounds were characterized by IR, 1H, and 13C NMR (in some cases also 15N NMR) spectroscopy, and EI and/or ESI mass spectrometry. The X-ray structure was determined for compound 3b. © 2012 Elsevier Ltd. All rights reserved. Source

Chlupaty T.,University of Pardubice | Padelkova Z.,University of Pardubice | Lycka A.,Research Institute for Organic Syntheses VUOS | Ruzicka A.,University of Pardubice
Journal of Organometallic Chemistry | Year: 2011

Lithium n-butyl amidinates (formally lithium salts of N',N-disubstituted amidoimides of pentanoic acid) with various substituents were prepared and characterized in solution by 1H, 7Li, 13C and 15N NMR spectra parameters in C6D6, THF-d 8 and Et2O-d10. The characteristic spectral parameters were compared with parent carbodiimides and amidines prepared by hydrolysis, where large solvent effects were described. Five of studied compounds were studied by X-ray diffraction techniques in the solid state. Lithium n-butyl amidinates containing less bulky substituents like isopropyl or cyclohexyl crystallize with Et2O or THF as centrosymmetric dimers with mutually parallel amidinate moieties. The lithium N,N'-bis[2,6-di(propan-2- yl)phenyl]n-butylamidinate crystallizes from Et2O solution as an asymmetric dimer. The first unit is composed by one ligand coordinated to one of lithium atoms. The lithium atom is also coordinated by one of the nitrogen atoms of the second ligand. The second nitrogen atom of the same ligand is coordinated to the second lithium atom which is also connected to the Et 2O molecule and the aromatic ring of the ligand in a η3-fashion. The same compound crystallizes from the THF solution as a monomeric bis-tetrahydrofuranate. © 2011 Elsevier B.V. All rights reserved. Source

Chlupaty T.,University of Pardubice | Padelkova Z.,University of Pardubice | Lyka A.,Research Institute for Organic Syntheses VUOS | Brus J.,Czech Institute of Macromolecular Chemical | Ruika A.,University of Pardubice
Dalton Transactions | Year: 2012

The new class of homo- and heteroleptic n-butyl-N,N′-disubstituted amidinato group 14 metal(ii) complexes were prepared by salt elimination from starting lithium amidinates and metal(ii) chlorides both in stoichiometric ratio 2:1 and 1:1, respectively. The target amidinates contain less bulky isopropyl or cyclohexyl as well as a sterically demanding aromatic substituent. Desired 1:1 Pb(ii) complexes are not accessible by the described procedure. Ligand transfer from Pb to Sn is taking place if homoleptic Pb(ii) compounds are reacted with SnCl 2. Prepared tetrylenes were characterized by 1H, 13C, 119Sn and 207Pb NMR spectroscopy in C 6D 6 or THF-d 8. X-Ray diffraction studies of one heteroleptic Ge(ii) monomeric where the coordination polyhedron of the three coordinated germanium atoms is a trigonal pyramid, two different dimeric structures of heteroleptic Sn(ii) complexes, one amidine hydroiodide byproduct and the oxidation product of the heteroleptic chloro Sn(ii) amidinate as a tetranuclear species with two Sn(iv) and two Sn(ii) atoms in central Sn 2O 2 planar ring were performed on appropriate single crystals. The dimer of one of the heteroleptic stannylenes reveals a new type of monomeric units connection, weak Sn-Cl contact and an interaction of the tin atom with delocalized N-C(C)-N system of the amidinato ligand of the second molecule. © The Royal Society of Chemistry 2012. Source

Jalovy Z.,University of Pardubice | Ek S.,Swedish Defence Research Agency | Ottis J.,University of Pardubice | Ruzicka A.,University of Pardubice | And 2 more authors.
Journal of Energetic Materials | Year: 2013

A process for the preparation of 1,1-diamino-2,2-dinitroethene suitable for scale-up was developed. The crucial features to allow scalability and enhance the process safety were the improved synthesis of 2-methoxy-2-methylimidazolidine-4,5-dione and its conversion into 2-hydroxy-2-methylimidazolidine-4,5-dione, which is a new intermediate in the synthesis of 1,1-diamino-2,2-dinitroethene. Its nitration produced 2-(dinitromethylidene)-imidazolidine-4,5-dione, whose hydrolysis into 1,1-diamino-2,2-dinitroethene was further improved. The use of trifluoroacetic acid to remove sulfuric acid prior to hydrolysis is no longer required. The described procedure yields no hazardous intermediates such as dinitromethane or 2-(dinitromethylidene)-5,5-dinitrodihydropyrimidine-4,6(1H,5H)-dione. Thus, the process safety was enhanced in comparison with the commercial production process starting from 2-methylpyrimidine-4,6-dione. © 2013 Copyright Swedish Defence Research Agency (FOI). Source

Matyas R.,University of Pardubice | Jirasko R.,University of Pardubice | Lycka A.,Research Institute for Organic Syntheses VUOS | Pachmaa J.,University of Hradec Kralove
Propellants, Explosives, Pyrotechnics | Year: 2011

The existence of two new types of chloroderivates of cyclic acetone peroxides - 3-(chloromethyl)-3,6,6,9,9-pentamethyl-1,2,4,5,7,8-hexoxonane and 3,6-bis(chloromethyl)-3,6,9,9-tetramethyl-1,2,4,5,7,8-hexoxonane was proved by HPLC/MS/MS and NMR in the reaction products when acetone and hydrogen peroxide are mixed in the presence of excess hydrochloric acid (molar ratio hydrochloric acid to acetone nc/na=2.5). The details of analysis, and the conditions under which these asymmetric chloroderivates of cyclic peroxides form, are described. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

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