- Catalytic and noncatalytic ammonolysis of chloropentafluorobenzene
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Ammonolysis of chloropentafluorobenzene both in the presence and in the absence of copper(I) salt results mainly in replacement of the para-and ortho-fluorine atoms with respect to chlorine rather than replacement of the chlorine atom. Ammonolysis of 4-chloro-2,3,5,6-tetrafluoroaniline and 2-chloro-3,4,5,6-tetrafluoroaniline in the absence of copper(I) salt yields exclusively the corresponding fluorine substitution products, whereas in the presence of copper(I) salt the chlorine atom is replaced. Successive ammonolysis of chloropentafluorobenzene in the presence of copper catalyst along these two paths was put into the basis of a new method for preparation of 2,3,5,6-tetrafluoro-1,4-phenylenediamine. * This study was financially supported by the Russian Foundation for Basic Research (project no. 99-03-33111), by the Ministry of Science and Technology of the Russian Federation (project no 9.3.01), and by the Ministry of Education of the Russian Federation (project no. 015.05.01.13).
- Selivanova,Pokrovskii,Shteingarts
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- Amino- and hydrodefluorination of polyfluoroaromatic amines with aqueous ammonia in a steel autoclave. Synthesis of highly pure tetrafluorophenylenediamines
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The action of aqueous ammonia on liexafhiorobenzene in a steel autoclave at 180-220 °C yields a mixture of isomeric tet rafluorophenylenediamines and 2,4,5-trifhioroplienylene-1,3-diamine. The content of the hydrodefluorination product significantly depends on the reaction temperature and time. Tetrafluorophenylene-1,3-diamine undergoes hydrodefluorination with aqueous ammonia in a steel autoclave at 200 °C to give 2,4,5-trifluorophenylene-1,3- diamine; when the additives of NH4F and/or FeCl3 are present, 2,5-difluorophenylene-1,3-diamine is additionally formed. The hydrodefluorination products are not formed during bis-aminodefluorination of hexafluorobenzene with aqueous ammonia in a glass reactor or with anhydrous ammonia (in a mixture with aprotic solvent) in a steel autoclave.
- Kusov,Rodionov,Vaganova,Shundrina,Malykhin
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- Selective mono-and diamination of polyfluorinated benzenes and pyridines with liquid ammonia
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Amination of pentafluoropyridine, 2,3,5,6-tetrafluoropyridine, 4-chlorotetrafluoropyridine, 3,5-dichlorotrifluoropyridine, octafluorotoluene, α,α,α,2,3,5,6-heptafluorotoluene, 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 isolation of particular polyfluorophenylenediamines from product mixtures formed in nonselective reactions of pentafluorobenzene and hexafluorobenzene with aqueous ammonia based on complexation with a crown ether is proposed.
- Vaganova,Kusov,Rodionov,Shundrina,Malykhin
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p. 2239 - 2246
(2008/09/20)
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- METHOD FOR PRODUCTION OF FLUORINATED PHENYLENEDIAMINE
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A method for the production of a fluorinated phenylenediamine is provided which comprises steps of reacting a diamide represented by the following formula with NaOCl at a molar ratio of the NaOCl to the diamide in the range of 2.0 - 6.0 and NaOH at a molar ratio of the NaOH to the diamide in the range of 1.8 - 6.0 is provided. According to this invention, the fluorinated phenylenediamine can be produced conveniently in a high yield.
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Page/Page column 23-25
(2008/06/13)
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