- 2, 3, 3, 3-tetrafluoropropene method for the synthesis of
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The invention discloses a method for synthesizing 2,3,3,3-tetrafluoropropene and belongs to the field of organic synthesis. The method comprises the following steps: (1) preparing 2-chloropropene from 1,2-dichloropropane, which serves as a raw material, through continuous catalytic cracking by adopting a fixed bed in the presence of beta-zeolite, which serves as a catalyst; (2) selectively chlorinating 2-chloropropene with chlorine gas under the catalysis of ferric chloride, so as to prepare 2,3,3,3-tetrachloropropylene; and (3) fluorating 2,3,3,3-tetrachloropropylene with hydrofluoric acid under the catalysis of SbF3 or SbF5, thereby obtaining 2,3,3,3-tetrafluoropropene. The synthesis route has the advantages that the source of raw materials is wide, the cost is low, and the product yield is high; and the obtained product can serve as an automotive air conditioning refrigerant and has a positive significance in reduction of greenhouse effect.
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Paragraph 0022
(2018/01/19)
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- PROCESS FOR THE PRODUCTION OF CHLORINATED PROPANES AND/OR PROPENES
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Processes for the production of chlorinated propenes are provided wherein the feedstream comprises 1,2-dichlropropane. The present processes make use of at least one reactor twice, i.e., at least two reactions occur in the same reactor. Cost and time savings are thus provided. Additional savings can be achieved by conducting more than two chlorination reactions, or all chlorination reactions, in one chlorination reactor, and/or by conducting more than two dehydrochlorination reactions, or all dehydrochlorination reactions, within a single dehydrochlorination reactor.
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Paragraph 0059-0061
(2013/06/05)
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- Dehydrochlorination of 1,2-dichloropropane by CO2 laser-induced breakdown; comparison with thermal elimination
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Dehydrochlorination of 1,2-dichloropropane (DCP) was conducted by thermal elimination and CO2 laser-reduced dielectric breakdown, which was induced by focusing the 10.6 μm lines of a CO2 TEA laser. Thermal dehydrochlorination proceeded by a four-centered mechanism at > 425 °C and by a surface-catalyzed radical process at 2000 °C.
- Ouchi, Akihiko,Sakuragi, Masako
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p. 2249 - 2255
(2007/10/03)
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- KrF Excimer Laser-induced Dehydrochlorination of 1,2-Dichloropropane
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Dehydrochlorination of 1,2-dichloropropane was conducted with and without irradiation of KrF excimer laser (248 nm).It afforded four products, cis-1-, trans-1-, 2-, and 3-chloropropene.The reaction was remarkably accelerated with irradiation of laser especially at the low temperatures.
- Ouchi, Akihiko,Niino, Hiroyuki,Yabe, Akira,Kawakami, Haruhiko
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p. 917 - 920
(2007/10/02)
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- Collisional Energy Transfer in Thermal Decomposition Reaction of 1,2-Dichloropropane
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The thermal decomposition reaction of 1,2-dichloropropane (1,2-DCP) was studied at temperatures from 663.2 to 703.2 K over the pressure range 0.04-10.0 Torr.The decomposition modes of 1,2-DCP were monitored via four reaction channels of unimolecular HCl eliminations and a negligible portion of a side radical chain reaction. 3-Chloropropene (3-CP), cis-1-chloropropene (cis-1-CP), trans-1-chloropropene (trans-1-CP), and 2-chloropropene (2-CP) were produced.Rate parameters for the thermal processes found in this study are k3(3-CP)/s-1=1013.61 +/- 0.30exp-1/RT>, kcis(cis-1-CP)/s-1=1012.90 +/- 0.70exp-1/RT>, ktrans(trans-1-CP)/s-1=1013.21 +/- 0.80exp-1/RT>, k2(2-CP)/s-1=1013.05 +/- 0.44exp-1/RT>, and ktot(total)/s-1=1013.70 +/- 0.50exp-1/RT>.The unimolecular thermal decomposition reactions of the four-channel 1,2-DCP system were carried out in the presence of a He bath gas to evaluate intermolecular-energy-transfer parameters.The average energies removed per collision from energized 1,2-DCP by bath gas are as follows: by the substrate, 1200 cm-1 for the stepladder model; by He, 250 cm-1 for the exponential model.The effects of active additives, CO2 and HCl, and the surface condition of the reaction vessel were also studied to ascertain the potential properties of the thermal decomposition reaction of 1,2-DCP.
- Yun, Sun Jin,Jung, Kyung-Hoon,Kang, Wee-Kyeong
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p. 5842 - 5847
(2007/10/02)
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- REDUCTION OF SOME POLYHALOGENATO- AND POLYACETOXYALLYLIC COMPOUNDS WITH TRIBUTYLTIN HYDRIDE IN THE PRESENCE OR ABSENCE OF A PALLADIUM CATALYST I. REDUCTION OF DICHLORO- AND DIACETOXY-PROPENES
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Radical-promoted tributyltin hydride reduction of 3,3-dichloropropene, (Z)-1,3-dichloropropene, or (E)-1,3-dichloropropene yields a mixture of the three possible regio-stereoisomeric monochloropropenes.The palladium-catalyzed reduction yields regiospecifically the two stereoisomeric 1-chloropropenes with a Z/E ratio which remains constant whatever the starting dichloropropene but which is not the thermodynamic ratio.The results are against a radical mechanism and strongly support a polar ?-allyl mechanism for the catalytic reactions.
- Guibe, Francois,Zigna, Anne-Marie,Balavoine, G.
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p. 257 - 266
(2007/10/02)
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- Bestimmung der Geschwindigkeitskonstanten der Reaktion von 1CH2 mit Fluor- und Chlorethen
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The rate constants for the addition of 1CH2 to fluoroethene and chloroethene have been determined using the known rate constant for the reaction of 1CH2 with ketene.The experiments yielded the results k4a(296 K) = (8.2 -/+ 0.6)E13 cm3 mol-1 s-1 k4b(296 K) = (2.9 -/+ 0.4)E13 cm3 mol-1 s-1. - Keywords: Chemical Kinetics / Gases / Photochemistry / Radicals
- Simon, F. G.,Heydtmann, H.
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p. 543 - 545
(2007/10/02)
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- Polyfunctionalized N-Tensides. VII. Substitution and Elimination in the Reaction of 1,2-Dihalogenoalkanes with Amines
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1,2-Dichloroalkanes, 1,2-Dibromoalkanes and mixtures of 1-bromo-2-chloroalkanes and 1-chloro-2-bromoalkanes react with primary or secondary amines and give both elimination and substitution products, often in a nearly 1:1 proportion.The elimination products are the cis and trans-1-halo-1-alkenes, the 2-halo-1-alkenes, the 1,3- and 2,4-dienes and the 1-alkenes.The main substitution products are the 1,2-bis-aminoalkanes.Physical dates, 1H-n.m.r.-spectra,surface tension values and CMC-dates are given.
- Beger, J.,Meerbote, E.
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- Thermal, Unsensitized Infrared Laser, and Laser SiF4 Sensitized Decomposition of 1,2-Dichloropropane
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1,2-Dichloropropane decomposes via four reaction channels forming 3-chloropropene, cis-1-chlopropene, trans-1-chloropropene, and 2-chloropropene.All pathways have been observed in thermal and laser-induced processes.Rate parameters for the thermal processes have been derived from comparative rate, single-pulse shock-tube studies.They are as follows: k(3-chloropene)=1E13.48exp(-27187/T) s-1; k(cis-1-chloropropene)=1E12.98exp(-26853/T) s-1; k(trans-1-chloropropene)=1E13.19exp(-27855/T s-1; k(2-chloropropene)=1E13.05exp(-29782/T) s-1; k(cis,trans-1-chloropropene)=1E13.34exp(-27235/T) s-1; k(total)=1E13.70exp(-27250/T) s-1; T=940-1060 K.The focused-laser experiments, both unsensitized as well as those sensitized with SiF4, yield product ratios which are very similar and suggest that the sensitized experiments also involve a photolytic process.With the thermal results as a base, we find lifetimes for laser-induced decomposition of ca. 1E-9 s and energy content prior to decomposition equivalent to 41 photons per molecule.In the nonfocused SiF4 sensitized experiments the results indicate a temperature of 1100 K and reaction time of ca. 1 μs.The cis-1-chloropropene to trans-1-chloropropene ratios from the laser experiments suggest that this represents a final product distribution.
- Tsang, W.,Walker, J. A.,Braun, W.
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p. 719 - 723
(2007/10/02)
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- The Dehydrochlorination of gem-Dichloroalkane and the Formation of Dienes from the Reactions of Butenes and Cyclohexene with Chlorine through Molten Salt
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The dehydrochlorination of 1,1-dichloropropane and 1,1-dichloro-3-methylbutane was carried out over molten salt catalysts (mainly ZnCl2-containing melts) using a conventional flow system.The cis/trans ratio (1.8) of the resulting olefins from 1,1-dichlorobutane was found to stand between the ratio (1.4) with 1,1-dichloro-3-methylbutane and the ratio (2.2) with 1,1-dichloropropane; this can be explained by considering the stereochemistry of the adsorbed carbonium ions.The detailed results of the reactions of three butene isomers with chlorine through molten salts were presented.The selective formation of butadiene was explained in terms of the thermally assisted attack of chlorine in the allylic positions of butene, followed by the 1,2- or 1,4-elimination of HCl from chlorobutenes, a process which is strongly assisted by the ZnCl2-containing melts.The reaction of 2-methyl-2-butene and cyclohexene with chlorine through molten salts was also undertaken.The addition of Zn powder to ZnCl2 melts in advance was found to improve the selectivity for the formation of isoprene and cyclohexadiene.Because the HCl evolved reacts instantly with Zn powder to afford ZnCl2 and hydrogen, Zn powder substantially prohibits the addition of HCl to dienes yielding chlorobutenes and chlorocyclohexenes.
- Kikkawa, Shoichi,Nomura, Masakatsu,Shimizu, Michimasa
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p. 2586 - 2591
(2007/10/02)
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