- Reactions of α-halonitrosoalkanes with resorcinol
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α-Halonitrosoalkanes react with resorcinol as nitrosylating agents to form 3-hydroxy-N-(2,4-dihydroxyphenyl)-1,4-quinone imine.
- Lyashenko,Kolomiets,Fokin
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- Selective Hydrodechlorination of CFC-113 to 1-Chloro-1,2,2-trifluoroethylene over Supported Ni Catalysts
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Various metal oxides have been examined as catalysts for the hydrodechlorination of CFC-113 to form 1-chloro-1,2,2-trifluoroethylene (CFC-1113).NiO was most effective and over silica gel- or Y-zeolite-supported Ni catalyst, 100 percent conversion of CFC-113 and 96percent selectivity to CFC-1113 were attained.
- Ueda, Wataru,Tomioka, Satoshi,Morikawa, Yutaka,Sudo, Motonori,Ikawa, Tsuneo
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- Photoreduction of 1,1,2-trichlorotrifluoroethane initiated by TiO2 particles
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Reductive dehalogenation of 1,1,2-trichlorotrifluoroethane (CFC 113) takes place upon illumination of air-free suspensions of TiO2 particles containing formate ions. Chloride ions and 1,2-dichlorotrifluoroethane (HCFC 123a) are the main reaction products. Reaction rates increase with increasing concentration of CFC even beyond the solubility limit of the Freon in water. Evidence is presented that a chain transformation of the Freon takes place in formate solutions. The results are explained assuming that reduction of the Freon proceeds via a radical chain mechanism, which involves participation of CFC and formate species located on as well as next to the oxide surface.
- Weaver,Mills
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Read Online
- Gas phase process for chlorotrifluoroethylene
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Disclosed are processes for the dechlorination of haloethanes comprising reacting in the gaseous phase a haloethane and reducing agent such as an alkene, an alkane, hydrogen or combinations of two or more of these, in the presence of a silicon-based catalyst.
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Page/Page column 12; 19-20
(2020/07/15)
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- Isomerization reaction of dichlorotrifluoroethane
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The invention discloses an isomerization reaction of dichlorotrifluoroethane. The reaction uses 2,2-dichloro-1,1,1-trifluoroethane as a raw material, and 1,2-dichloro-1,1,2-trifluoroethane (R123a) and1,1-dichloro-1,2,2-Trifluoroethane (R123b) are prepared under the action of an isomerization catalyst, wherein the isomerization catalyst is a mixture of AlF3 and AlCl3. The reaction has the advantages of simple process, strong operability, low cost, and the like.
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Paragraph 0022-0035
(2019/12/25)
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- PROCESS FOR THE FLUORINATION OF HALOOLEFINS
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A process for the fluorination of haloolefins with elemental fluorine in the presence of anhydrous HF proceeds with high yield and selectivity in the product deriving from the addition of fluorine to the carbon-carbon double bond.
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Page/Page column 6-7
(2012/02/02)
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- Selective reduction of halopolyfluorocarbons by organosilicon hydrides
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It is demonstrated that silicon hydrides can be used for reduction of polyfluorinated halocarbons. For example, the reaction between CF3CCl2F and excess triethylsilane, catalyzed by benzoyl peroxide, leads to the formation of a mixture containing CF3CHClF (major), CF3CH2F, and ClSi(C2H5)3. On the other hand, the reaction of chlorofluoroalkanes, containing an internal -CCl2- group readily proceeds with reduction of both chlorines, leading to compounds such as (CF3)2CH2 and CF3CH2C2F5. In contrast to chlorofluoroalkanes, bromofluoroalkanes are much more reactive and reaction with hydrosilane rapidly proceeds without the catalyst at elevated temperature.
- Petrov, Viacheslav A.
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p. 7294 - 7297
(2007/10/03)
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- Deuterium isotope studies of the hydrofluorination of chloroethenes over chromia catalysts
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The mechanism of the catalytic fluorination of chloroalkenes over a chromia catalyst has been investigated by examining the effects of substituting DF for HF as the fluorine source for reaction with tetrachloroethene and trichloroethene.At a temperature of 250 degC and a HF (DF)/alkene molar ratio of 4.2:1, the rate of conversion of tetrachloroethene is increased by using DF and there is a concomitant increase in the selectivity to some chlorofluoroalkanes and a decrease in the selectivity to chlorofluoroalkenes.The opposite behaviour observed for the halogenated alkenes and alkanes indicates that the alkenes are not important intermediates in the production of the alkanes by a series of hydrofluorination and dehydrochlorination reactions.For tetrachloroethene, the main reaction pathway to the alkanes is a direct chlorine/fluorine exchange over a heavily fluorinated chromia surface with minimal C-H/C-D cleavage of intermediates.Substitution of DF for HF causes no change in the product selectivities from reaction with trichloroethene over chromia catalysts.However, the presence of dideutero - and monodeutero - products shows that both chlorine/fluorine exchange and HF addition / HCl elimination pathways are occurring for the less-substituted alkene.
- Kavanagh, David M. C.,Ryan, T. Anthony,Mile, Brynmor
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p. 167 - 176
(2007/10/02)
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- Bi-Pd Catalyst for Selective Hydrodechlorination of 1,1,2-Trichlorotrifluoroethane to Trifluoroethene, a Key Intermediate to 1,1,1,2-Tetrafluoroethane as a CFC Replacement for Refrigeration
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Trifluoroethene, a key intermediate to 1,1,1,2-tetrafluoroethane (FC-134a), was catalytically synthesized with 80-90percent selectivity at 80-100percent conversion in the hydrodechlorination of 1,1,2-trichlorotrifluoroethane (FC-113) at 200-250 deg C under an atmospheric pressure over Bi-Pd (Bi/Pd = 0.4-0.6) supported on metal oxides.
- Ohnishi, Ryuichiro,Suzuki, Isao,Ichikawa, Masaru
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p. 841 - 844
(2007/10/02)
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- Reduction of polyhalofluoroalkanes with formate to hydrogen-bearing alternatives initiated by carbon dioxide anionic radical
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Reduction of polyhalofluoroalkanes with formate in the presence of a catalytic amount of persulfate is described.Such a reagent posseses good selectivity in the reduction of carbon-chlorine bonds.A chain mechanism including carbon dioxide anionic radicals and polyhalofluoroalkyl radicals is proposed.
- Hu, Chang-Ming,Tu, Ming-Hu
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p. 105 - 108
(2007/10/02)
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- FLUORINATION OF HYDROGEN-CONTAINING OLEFINS WITH ELEMENTAL FLUORINE
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The hydrohalo-olefins cis and trans CHCl=CHCl, CHCl=CCl2, CHCl=CH-CH2Cl and CH2=CCl-CH2Cl have been fluorinated with elemental fluorine to give good yields of hydrohalofluoroalkanes.The best operational conditions for F2 addition to the double bond rather than hydrogen and/or chlorine atom substitution, dimerization and oligomerization of radical intermediates have been studied.Pleriminary studies on the reaction of Freon 12 and Freon 22 towards elemental fluorine have also been carried out.
- Conte, L.,Gambaretto, G. P.,Napoli, M.,Gervasutti, C.
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p. 319 - 326
(2007/10/02)
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- Reaction of Bistrifluoromethylaminosulphenyl Chloride with Fluoro-olefins and Hexafluorobut-2-yne under Free-radical Conditions
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Reaction of bistrifluoromethylaminosulphenyl chloride with unsymmetrical fluoro-olefins in daylight or under photochemical conditions gives both possible 1:1 adducts (ca. 1:1) arising from homolytic fission of the S-Cl bond.Addition to octafluorobut-2-ene and hexafluorobut-2-yne gives mixtures of the syn- and anti- adducts.
- Service, Colin F.,Tipping, Anthony E.
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p. 135 - 140
(2007/10/02)
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