- NOUVELLE METHODE de DETERMINATION des INDICES de REFRACTION d'ALCANES PERHALOGENES
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We propose a new formula such as (*) in order to calculate the refractive index (n) of perhalogenated alkanes containing Ni atoms i(C,F,Cl, or Br), at a given temperature.The contributions Ki of each element are determined at different temperatures.This method which has been tested on a series of compounds whose experimental values of the refractive index are given is the literature, leads to results which are much nearer reality than those given by different methods known so far.
- Bosc, D.,Pietrasanta, Y.,Rigal, G.,Rousseau, A.
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- Preparation of highly fluorinated cyclopropanes and ring-opening reactions with halogens
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Various highly fluorinated cyclopropanes 1 were prepared by reaction of the appropriate fluorinated olefins with hexafluoropropylene oxide (HFPO) at 180 °C. The fluorinated nitrile le was converted to the triazine derivatives 2a and 2b by catalysis with Ag2O and NH3/(CF3CO)2O, respectively. The fluorinated cyclopropanes reacted with halogens at elevated temperatures to provide the first useful, general synthesis of 1,3-dihalopolyfluoropropanes. At 150-240 °C, hexafluorocyclopropane and halogens X2 produce XCF2CF2CF2X (X = Cl, Br, I) in 50-80% isolated yields. Pentafluorocyclopropanes c-C3F5Y [Y = Cl, OCF3, OC3F7 and OCF2CF(CF3)OCF2CF2Z; Z = SO2F, CN, CO2Me] react regiospecifically at 150 °C to give XCF2CF2CFXY, c-C3F5Br reacts regioselectively with Br2 to give a 16.7:1 mixture of BrCF2CF2 CFBr2:BrCF2CFBrCF2Br, whereas c-C3F5H reacts unselectively with I2 to produce a statistical 2:1 mixture of ICF2CF2CFHI:ICF2CFHCF2I. Tri- and di(pentafluorocyclopropyl) derivatives 2 also undergo ring-opening reaction with halogens to give 16 and 17. Upon treatment of tetrafluorocyclopropanes 1j, 1k, and 1l with Br2 or I2, ring opening occurred exclusively at substituted carbons to give XCF2CF2CXY2. Thermolysis of the ring-opened product ICF2CF2CFIORF at 240 °C gave RFI and ICF2CF2COF in high yields.
- Yang, Zhen-Yu
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- Method and device for preparing 2,3,3,3-tetrafluoropropene
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The invention provides a method and a device for preparing 2,3,3,3-tetrafluoropropene. The device for preparing 2,3,3,3-tetrafluoropropene comprises a circulation flow reactor, a first rectifying tower, a first cooling tower, a second rectifying tower and a second cooling tower. The method provided by the invention adopts a continuous loop reactor technology to realize the technology of separatinghydrogen chloride by-products in real time under the reaction conditions, so that the selectivity of the reaction is greatly improved; since the continuous circulation operation of the raw materialsis realized, the total conversion rate of the reaction is very high. 2,3,3,3-tetrafluoropropene obtained by the method is low in cost; the production technology has the advantages of being few in by-products and wastes and suitable for industrial large-scale production.
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Paragraph 0084-0087; 0094-0097
(2019/01/14)
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- PROCESS FOR PRODUCTION OF 2,3,3,3-TETRAFLUOROPROPENE
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The present invention provides a process for producing 2,3,3,3-tetrafluoropropene including the following reaction steps: (i) reducing a halogenated fluoropropane represented by formula (1): ACF2CF2CH2FyAz, wherein A is Cl, Br, or I; x is an integer from 0 to 2; y and z are each an integer from 0 to 3; and the total number of x, y, and z is 3, to produce a 1-halogenated-1,1,2,2-tetrafluoropropane represented by formula (2): ACF2CF2CH3; and (ii) contacting the 1-halogenated-1,1,2,2-tetrafluoropropane obtained in step (i) with a catalyst in a gas phase to produce 2,3,3,3-tetrafluoropropene. According to the invention, 2,3,3,3-tetrafluoropropene (HFO-1234yf) can be produced in a high yield, using inexpensive starting materials.
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Page/Page column 14-15
(2010/04/03)
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- PROCESSES FOR PRODUCING AND COMPOSITIONS COMPRISING 2,3,3,3-TETRAFLUOROPROPENE AND/OR 1,2,3,3-TETRAFLUOROPROPENE
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A process is disclosed for making CF3CF=CH2 or mixtures thereof with CHF=CFCHF2. The process involves contacting CCI3CF2CF3 and optionally CCI2FCF2CCIF2 with H2 in the presence of a catalyst including a catalytically effective amount of palladium supported on a support of alumina, fluorided aluminaand/or aluminum fluoride, to produce a product mixture including CH2=CFCF3 (and when CCI2FCF2CCIF2 is present, CHF=CFCHF2); recovering CH2=CFCF3 or a mixture thereof with CHF=CFCHF2 from the product mixture; and optionally, separating at least a portion of any CHF=CFCHF2 in the product mixture from the CH2=CFCF3 in the product mixture. The mole ratio of H2 to the total of CCI3CF2CF3 and CCI2FCF2CCIF2 fed to the reaction zone is between about 1 :1 and about 5:1. The present invention also provides another process for making CH2=CFCF3 Or mixtures thereof with CHF=CFCHF2 This process involves (a) reacting CCI3CF2CF3 and optionally CCI2FCF2CCIF2 with H2 in the presence of a catalytically effective amount of a hydrogenation catalyst to form CH3CF2CF3 (and when CCI2FCF2CCIF2 is present, CH2FCF2CHF2); (b) dehydrofluorinating CH3CF2CF3 and optionally any CH2FCF2CHF2 from (a) to form a product mixture including CH2=CFCF3, and if CH2FCF2CHF2 is present, CHF=CFCHF2; (c) recovering CH2=CFCF3 or a mixture thereof with CHF=CFCHF2 from the product mixture formed in (b); and optionally (d) separating at least a portion of any CHF=CFCHF2 in the product mixture formed in (b) from the CH2=CFCF3 in the product mixture formed in (b). The present invention also provides compositions involving CH2=CFCF3 and/or CHF=CFCHF2, including compositions useful as refrigerants, foam blowing agents, cleaning agents and aerosols and azeotropic compositions involving (a) CF2HCF=CFH and (b) HF.
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Page/Page column 16-17
(2008/12/05)
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- 19F nuclear magnetic resonance studies of halogenated propanes
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The relationship between 19F chemical shifts in halogenated propanes and their structures are elucidated using MNDO calculations to determine the population of rotamers.The pairs of atom gauche to a fluorine atom and van der Waals interaction between the two terminal substituents are responsible for the 19F chemical shifts.The differences among chemical shifts in diastereomers are also discussed in terms of the conformation of molecule.
- Tanuma, T.,Ohnishi, K.,Okamoto, H.,Miyajima, T.,Morikawa, S.
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p. 259 - 284
(2007/10/02)
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- TELOMERISATION DU TETRAFLUOROETHYLENE AVEC LE TETRACHLORURE DE CARBONE PAR CATALYSE REDOX
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The redox telomerization of tetrafluoroethylene with carbon tetrachloride using the FeCl3/benzoin complex as catalyst has been studied.The CFen transfer constants of this reaction are measured and compared to the results obtained und
- Battais, A.,Boutevin, B.,Pietrasanta, Y.,Bertocchio, R.,Lantz, A.
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p. 215 - 232
(2007/10/02)
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- Synthesis of > and Some Chlorofluoropropenes
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The starting substances C3Cl5F3 (1) and C3Cl4F4 (2) prepared earlier by the addition of CCl3F with CClF=CClF and/or CF2=CClF were utilized for the synthesis of chlorofluoropropenes by means of fluorination, reduction of C-Cl bonds in halogenopropanes, and final dehalogenation, all the reactions being performed at atmospheric pressure.The reaction conditions permit laboratory scale production.The contents of the isomeric admixtures in the resultant products were determined by NMR spectroscopy.The starting halogenopropanes 1, 2 represent mixtures of isomers, but in course of the individual synthetic steps the content of the main isomer was generally increased.In comparison with previously used syntheses, our procedure proves advantageous for the synthesis of "perfluoroallylchloride" (9a, isomer purity 95percent).Using this procedure a number of halogenopropanes were prepared and dechlorinated to give the corresponding halogenopropenes (isomer purity percent): CClF2-CClF-CCl2F (2a, 87), CF3-CClF-CCl3 (2b, 78), CClF2-CClF-CClF2 (3a, 87), CF3-CClF-CCl2F (3b, 90), CF3-CClF-CHCl2 (5a, 90), CF3-CClF-CHClF (6a, 73), CClF2-CF=CClF (8a, 93), CF3-CF=CCl2 (8b, 84), 9a, CF3-CF=CClF (9b, 86) and CF3-CF=CHCl (11a, 84).The minor isomers in substance 2 yielded products which were isolated after being combined from several preparations: CClF2-CF2-CHCl2 (5b, 84); CClF2-CF=CHCl (10a, 98), which by addition of chlorine yielded CClF2-CClF-CHCl2 (4a, 95).The NMR spectra of all the major and minor products, excluding perhalogenopropanes, are listed.
- Paleta, Oldrich,Kvicala, Jaroslav,Guenter, Jaroslav,Dedek, Vaclav
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p. 920 - 924
(2007/10/02)
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