Reaction of pentafluorobenzoylpyruvic acid with amines

Reactions of pentafluorobenzoylpyruvic acid with amines afford the respective enamines. The intramolecular cyclization of the latter results inN-substituted 4-quinolone-2-carboxylic acids. Ammonia and triethylamine favor the cyclization of pentafluorobenzoylpyruvic acid to 2-carboxychromone.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 299–302, February, 1994.     

Reaction of 2-amino-4-imino-2-perfluoropentene with ethylenediamine and diethylenetriamine

The transamination of 2-amino-4-imino-2-perfluoropentene with ethylenediamine gives the corresponding 6-fluoro-5,7-bis(trifluoromethyl)-2,3-dihydro-1H-1,4-diazepine. The transamination of 2-amino-4-imino-2-perfluoropentene by diethylenetriamine is accompanied by intramolecular nucleophilic substitution of the α-fluorine atom to form 1,9-bis(trifluoromethyl)-3,4,6,7-tetrahydro-2H-pyrazino[1,2-a]pyrazine whose structure was established by an X-ray structural investigation. Several salts of this bicyclic compound and its complex with BF₃ have been described. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1773–1776, October, 1993.     

Reaction of 2-halofluoroalkyl-containing β-ketoesters with N-dinucleophiles

Conclusions During the reaction of hydrazines and o-phenylenediamine with 2-halosubstituted (3-keto-esters, including fluoroalkyl substituted, two reaction paths are realized; substitution of the halogen atoms in position 2 by hydrogen and condensation with formation of various compounds depending on the structure of the starting -ketoester and dinucleophile.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2527–2535, November, 1987.     

Conformational structure of esters of fluorinated acylpyruvic acids

Esters of fluorinated acylpyruvic acids were obtained for the first time. PMR and IR spectroscopy, dipole moment measurements, and quantum chemical calculations showed that these compounds exist as equilibrium mixtures of E and Z enolic isomers.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1410–1414, June, 1990.     

Electronic structure and stability of complex hydrides Mg<Subscript>2</Subscript><Emphasis Type="Italic">M</Emphasis>H<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> (<Emphasis Type="Italic">M</Emphasis> = Fe,Co)

This paper reports on the results of theoretical investigations carried out for the hydrides Mg₂FeH₆ and Mg₂CoH₅ and the mixed hydride Mg₂(FeH₆)_0.5(CoH₅)_0.5 in terms of the full-potential linearized augmented plane wave (FLAPW) method. It has been shown that the partial substitution of the Co atoms for the Fe atoms leads to a slight increase in the stability of the hydride, but, at the same time, makes it impossible to increase the stability of the alloy. The high stability of the hydrides under investigation has been explained by the strong bonding between atoms of the transition metal and hydrogen.     

Synthesis of 2(3)-ethoxycarbonyl-5,6,7,8-tetrafluorochromones

The hitherto unknown ethyl pentafluorobenzoylpiruvate was prepared by condensing pentafluoroacetophenone with diethyl oxalate. Intramolecular cyclization of this ester or of its copper(II) chelate, as well as of ethyl 2-(ethoxymethylene)pentafluorobenzoylacetate affords 2- and 3-ethoxycarbonyl-5,6,7,8-tetrafluorochromones. Hydrolysis of the latter followed by decarboxylation gives 5,6,7,8-tetrafluorochromone.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 362–364, February, 1993.     

Thermal decomposition of peroxide derivatives of polyfluorinatedβ-ketoesters

The thermal flow microcalorimetric method was used to determine the kinetic parameters for the thermal decomposition of peroxide derivatives of polyfluorinated-ketoesters and the decomposition products were established.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1647–1650, July, 1990.     

Interaction of fluorine-containing 1,3-dicarbonyl compounds with polyamines

In the reaction of fluorinated copper(II) 1,3-diketonates with diethylenetriamine (or triethylenetetramine) in CHCl₃, N,N-bis(1,3-aminovinylketones) are formed in 21–35% yields. Fluorine-containing 1,3-diketones and 1,3-ketoesters, upon interaction with polyamines without solvent, undergo acid cleavage, forming the corresponding amides. The copper(II) 1,3-ketoesterates are readily cleaved in CHCl₃ at 25°C in excess triethylenetetramine or ethylenediamine.Department of Fine Organic Synthesis, Institute of Organic Chemistry, Ural Branch, Russian Academy of Sciences, 620219 Ekaterinburg. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp. 2591–2596, November, 1992.     

A new approach to the synthesis of fluorinated chromones

The condensation of two molecules of ethyl pentafluorobenzoylacetate gives 1-oxo-3-penta fluorophenyl-1H-pyrano[4,3-b]6,7,8,9-tetrafluorochromone.Department of Fine Organic Synthesis, Institute of Organic Chemistry, Urals Branch, Russian Academy of Sciences, 620219 Ekaterinburg. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 9, pp. 2186–2188, September, 1992.