Selective mono-and diamination of polyfluorinated benzenes and pyridines with liquid ammonia
作者:T. A. Vaganova、S. Z. Kusov、V. I. Rodionov、I. K. Shundrina、E. V. Malykhin
DOI:10.1007/s11172-007-0351-2
日期:2007.11
decafluoro-m-xylene, decafluorobiphenyl, hexafluorobenzene, and pentafluorobenzene with liquid ammonia was investigated. Bis-aminodefluorination temperatures for the majority of substrates were shown to exceed significantly the corresponding temperatures of monoaminodefluorination. The optimal conditions for selective preparation of mono-and diaminopolyfluoro(het)arenes were elucidated. An efficient method for
Polyfluoro-heterocyclic compounds. Part VI. Nucleophilic substitution in tetrafluoro-4-nitropyridine
作者:R. D. Chambers、J. Hutchinson、W. K. R. Musgrave
DOI:10.1039/j39660000220
日期:——
5,6-tetrafluoro-4-nitrobenzene which gives exclusive replacement of fluorine ortho to the nitro-group. The pyridine-ring nitrogen is the greatest single factor in determining the orientation of nucleophilic attack. Competition experiments show relative reactivities to be in the order: pentafluoropyridine ≈ pentafluoronitrobenzene > tetrafluoro-4-nitropyridine. Fluorine-19 n.m.r. spectra of derivatives
Synthesis and characterization of novel fluorinated pyridine-based polyimides
作者:Tamara A. Vaganova、Inna K. Shundrina、Soltan Z. Kusov、Vladimir I. Rodionov、Evgenij V. Malykhin
DOI:10.1016/j.jfluchem.2013.01.037
日期:2013.5
New pyridine-containing polyimides based on fluorinated gamma-X-pyridylenediamines (X = H, Cl, NH2, O-linkage) and dianhydride 6FDA were prepared by one-step polycondensation in benzoic acid melt. Molecular weight of the polymers enlarges with an increase of nucleophilicity of the pyridylenediamines and solubility of the macromolecules in the reaction medium. 4,4'-Oxydianiline was used as a co-monomer to prepare high-molecular pyridine-containing PI films with good mechanical properties. The polyimides and co-polyimides obtained are soluble in amide solvents, have good thermal and thermooxidative characteristics. Parameters of the polyimides pyrolysis, which provide consecutive elimination of different elements, were found. (C) 2013 Elsevier B.V. All rights reserved.