- Synthetic method of octafluorocyclopentene
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The invention relates to a synthetic method of octafluorocyclopentene, and belongs to the technical field of chemical engineering. The method comprises the following steps: dissolving perfluorocyclopentane, FeCp*2 and trifluoromethanesulfonate of alkali metal in a dry aprotic solvent, conducting stirring, conducting irradiating with a mercury lamp for 1-2 hours under the protection of protective gas to obtain a reaction product, and conducting separating and purifying to obtain octafluorocyclopentene. In the method, reactants react fully, operation is simple, reaction conditions are mild, hightemperature and high pressure are avoided, pollution discharge is easy after the reaction is finished, three wastes are few, aftertreatment is simple, the problem that many impurities are caused dueto the fact that fluorine-chlorine exchange cannot react fully is solved, the solvent can be recycled, pollution in the synthesis process is reduced, and the method is environmentally friendly and belongs to a green synthesis method.
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- Preparation method of octafluorocyclopentene
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The invention relates to a preparation method of octafluorocyclopentene, and belongs to the technical field of chemical engineering. The method comprises the following steps: (1) dissolving 1, 2-dichlorocyclopentane in carbon tetrachloride, cooling to 0-20 DEG C, introducing diluted fluorine gas, stirring, heating to 30-50 DEG C, carrying out fluorination and fluorination reaction for 1-2 hours to obtain a product, and separating and purifying to obtain 1, 2-dichlorooctafluorocyclopentane; and (2) dissolving a reductive dechlorination reagent in a dry polar solvent, stirring, protecting by protective gas, heating to 50-80 DEG C, dropwise adding the 1, 2dichlorooctafluorocyclopentane by adopting a constant-pressure dropping funnel, continuously reacting for 0.5-1.5 hours when no foam is generated, and collecting the generated gas by using a cold trap. The method is simple to operate; high-temperature and high-pressure conditions are not set, and reaction conditions are mild; and less three wastes are generated, the environmental pressure is low, and the method belongs to a green synthesis process.
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Paragraph 0029; 0031-0032; 0034-0035; 0037
(2021/04/14)
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- Continuous chemical industry preparation method of octafluorocyclopentene
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The invention relates to the field of fine chemical industry, in particular to a continuous chemical industry preparation method of octafluorocyclopentene. The continuous chemical industry preparationmethod comprises the steps of gas phase chlorination reaction, intermediate product purification, gas phase fluorination reaction and the like. The final product octafluorocyclopentene is obtained from easily obtained raw material cyclopentene by using a gas phase method, compared with an existing liquid phase fluorination-method technology for preparing octafluorocyclopentene, the preparation method of the octafluorocyclopentene has the advantages of cheap reaction raw materials, simplicity in reaction, no applicability to solvent, no organic waste liquid generation, short reaction time, high product yield, capability of continuous production and great prospect of industrial production.
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Paragraph 0020-0054
(2019/12/25)
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- Preparation method of halogenation cycloolefin
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The invention relates to a preparation method of halogenation cycloolefin and belongs to the field of chemical synthesis. According to the preparation method, in an amide or alkylamine solvent, with halogenation cycloparaffin as a raw material, a dehalogenation reaction is conducted, and the target product halogenation cycloolefin is obtained. According to the method, the reaction conditions are mild, the yield of the halogenation cycloolefin is high, dangerous reduction agents such as metal or hydrogen do not need to be used, the technology is safe and reliable, solid waste such as metal halide is not generated, and a common distillation means can be used for effective industrial separation.
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Paragraph 0064; 0065
(2019/08/20)
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- Industrial production method for perfluorocyclopentene
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The invention discloses an industrial production method for perfluorocyclopentene, and belongs to the field of fine chemical intermediate synthesis. Cyclopentene, chlorine and pyridine hydrofluoride which are used as raw materials undergo high-temperature chlorination in a solvent sulfolane to obtain octachlorocyclopentene, and the octachlorocyclopentene and pyridine hydrofluoride undergo high-temperature fluorination substitution to obtain the perfluorocyclopentene. Residues obtained after the separation of the product undergo reduced pressure distillation to obtain the solvent sulfolane which can be reused. The method allows the product yield to reach 45-55%, the product content to be more than 99%, the water content to be less than 0.1% and the chloride ion content to be less than 0.1%. The method has the advantages of no pollution in the production process, green production process, high yield, simple steps, facilitation of the reduction of the production cost, high product purity, and facilitation of later application.
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- Industrialized production method for 1,2,3,3,4,4,5,5-octafluorocyclopentene
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The invention discloses an industrialized production method for 1,2,3,3,4,4,5,5-octafluorocyclopentene, and belongs to the field of synthesis of fine chemical intermediates. Cyclopentene, a chlorine gas and anhydrous potassium fluoride are used as raw materials, sulfolane is used as a solvent, chlorination is performed step by step through programmed heating, and the chlorinated product and the potassium fluoride are subjected to a high-temperature substitution reaction to form the 1,2,3,3,4,4,5,5-octafluorocyclopentene. According to the method provided by the invention, kettle residues afterseparation of the product can be reused after the solvent sulfolane is distilled out under reduced pressure; and the method provided by the invention has the advantages of simple production process steps, greenness, environmental protection, a high yield and low production cost, and the obtained product has high purity and is beneficial to a later application.
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Paragraph 0046-0080
(2018/07/30)
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- Study on the Preparation of Cr-based Catalysts Doped by Zn using Sol–Gel Auto-Combustion Method and Its Application for Synthesis of 1-Chloro-2,3,3,4,4,5,5-heptafluorocyclopentene
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High-surface-area chromium-based catalysts in the presence of a small amount of zinc were prepared via a sol–gel auto-combustion method using chromic nitrate, zinc nitrate, and citric acid. First, the auto-combustion behavior of the dried gel was investigated by derivative thermogravimetry and (DTG)-TG and infrared (IR) techniques. The results revealed that the dried gel exhibited self-propagating combustion properties. Second, the as-burnt powders were characterized by IR, X-ray diffraction (XRD), Brunauer–Emmett–Teller analysis (BET), and scanning electron microscopy (SEM). The findings showed that the gels were directly converted into CrZn-O nanoparticles with high surface area during the auto-combustion process. Third, the pre-fluorination Cr-Zn catalysts were characterized by XRD, BET, SEM, X-ray photoelectron spectroscopy (XPS), and Fourier transform (FT)-IR spectroscopy of pyridine adsorption techniques. It was found that the presence of zinc led to significant structural changes in the catalyst, the particle size was smaller, the surface area became larger, and more active sites appeared. Finally, the catalytic activities of the samples were tested for the fluorination of 1,2-dichlorohexafluorocyclopentene (1,2-F6) with anhydrous hydrogen fluoride. The obtained results indicated that the pre-fluorination activated Cr-Zn catalysts prepared by this sol–gel auto-combustion method exhibited high efficiency in the synthesis of cyclic hydrofluorocarbons.
- Han, Yajun,He, Jinwei,Wu, Zhenhai,Zhou, Xiaomeng
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p. 1128 - 1138
(2017/10/31)
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- Synthesis of 1,1,2,2,3,3,4-heptafluorocyclopentane as a new generation of green solvent
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1,1,2,2,3,3,4-Heptafluorocyclopentane is a new generation of green solvent. It was synthesized by the liquid-phase fluorination reactions from hexachlorocyclopentadiene to 1-chloroheptafluoro-cyclopentene in the presence of KF in DMF and by the vapor-phase hydrogenation reaction from 1-chloroheptafluorocyclopentene to 1,1,2,2,3,3,4-heptafluorocyclopentane in the presence of Pd-based hydrogenation catalyst. Quantum chemical calculations for the isomers energies using Gaussian09 were conducted to verify the chemical equilibriums between isomers of trichloropentafluorocyclopentene or dichlorohexafluorocyclopentene in the fluorination reactions. Possible mechanisms for 1,1,2,2,3,3,4-heptafluorocyclopentane synthesis were proposed.
- Zhang, Chengping,Qing, Feiyao,Quan, Hengdao,Sekiya, Akira
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- A novel strategy for synthesis of dichlorooctafluorocyclopentane and reaction mechanism investigation
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A novel method was used for preparing 1,1-dichlorooctafluorocyclopentane and 1,2-dichlorooctafluorocyclopentane through the reaction of 1,2-dichlorohexafluorocyclopentene, anhydrous hydrogen fluoride, and chlorine. A series of single- and multi-component catalysts were prepared by means of impregnation and coprecipitation, respectively. The catalyst containing Fe(III), Zr(IV), Co(II), Zn(II) and Cu(II) showed the highest catalytic activity among these catalysts. Moreover, the main reaction routes and catalytic mechanism were investigated through experiments and theoretical analysis. Given the environmental and economic benefits, this method has a great application potential in industrial production.
- Zhang, Pingli,Lu, Dayong,Zhou, Biao,Zhou, Xiaomeng
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- PROCESSES FOR THE SYNTHESIS OF 3-CHLOROPERFLUORO-2-PENTENE, OCTAFLUORO-2-PENTYNE, AND 1,1,1,4,4,5,5,5-OCTAFLUORO-2-PENTENE
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Disclosed is a process comprising reacting CF3CF2CCI2CF2CF3 (CFC-41 -10mca) with hydrogen in the presence of a dehalogenation catalyst to produce CF3CF2CCI=CFCF3 (CFC-1419myx). Also disclosed herein is a process comprising reacting CF3CF2CCI=CFCF3 (CFC- 1419myx) with hydrogen in the presence of a dehalogenation catalyst to produce CF3CF2C≡CCF3 (octafluoro-2-pentyne). Also disclosed herein is a process comprising reacting CF3CF2CCI2CF2CF3 (CFC-41 -10mca) with hydrogen in the presence of a dehalogenation catalyst to produce CF3CF2C≡CCF3 (octafluoro-2-pentyne). In addition, a process for reacting CF3CF2C≡CCF3, in a pressure vessel, with a Lindlar catalyst and hydrogen to produce CF3CF2CH=CHCF3 (1,1,1,4,4,5,5,5-octafluoro-2- pentene) is disclosed.
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Page/Page column 14-15
(2009/07/18)
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- DRY-ETCHING GAS FOR SEMICONDUCTOR PROCESS AND PREPARATION METHOD THEREOF
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The invention is a method for continuously preparing highly pure octafluorocyclopentene for use in dry-etching processes. The method includes reacting octachlorocyclopentene with KF in a continuous manner, and purifying crude octafluorocyclopentene. In the reacting step, two KF-charged filters are installed in parallel and allowed to communicate with a reactor containing octachlorocyclopentene in an alternating manner to produce crude octafluorocyclopentene. In the purifying step, organics having lower boiling points than octafluorocyclopentene are removed, and metal ingredients and organics having boiling points higher than octafluorocyclopentene are separated to recover octafluorocyclopentene as a gas. The gaseous octafluorocyclopentene composition contains C5F8 in an amount of 99.995 vol % or higher, nitrogen in an amount of 50 vol ppm or less, oxygen in an amount of 5 vol ppm or less, water in an amount of 5 vol ppm or less, and metal ingredients in an amount of 5 wt ppb or less.
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Page/Page column 6-7
(2008/06/13)
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- Extremely facile ring inversion and rearrangement in fluorobicyclo[2.1.0]pentanes
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cis-1,2,3,4,5,5-Hexafluorobicyclo[2.1.0]pentane and 1,2,4,5-tetrafluorobicyclo[2.1.0]pentane have been synthesized from hexafluorobenzene. The former hydrofluorocarbon, which exists entirely in the endo configuration, rearranges to cis-1,2,3,3,4,5-hexafluorocyclopentene below room temperature (Ea = 21.9 kcal/mol, log A = 13.4). The latter undergoes degenerate ring inversion with extraordinary ease (ΔG? = 6.8 ± 0.2 kcal/mol at -55 °C). Density functional calculations indicate that significant bonding between the bridgehead carbons is retained in the ring inversion transition state. Analogous calculations predict for hexafluorobicyclo[1.1.0]butane a considerably lower barrier for ring inversion and more 1,3-bonding in the transition state.
- Wei, Yanjun,Liu, Yufa,Wong, Terrence,Lemal, David M.
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p. 688 - 703
(2008/09/16)
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- GAS FOR PLASMA REACTION AND METHOD FOR PRODUCTION THEREOF
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A high-purity gas for plasma reaction having an octafluorocyclopentene purity of at least 99.9% by volume based on the total volume of the gas for plasma reaction, wherein the total content of nitrogen gas and oxygen gas, contained as trace gaseous ingredients of the remainder, is not larger than 200 ppm by volume. This high-purity gas for plasma reaction can be produced by (1) a process of distilling crude octafluorocyclopentene in an inert gas of group 0, or (2) a process of distilling crude octafluorocyclopentene into a purity of at least 99.9% by volume, and then, removing an impurity remainder.
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- Process for the preparation of fluorinated olefin
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In a process for preparing a fluorinated olefin having a carbon—carbon double bond, the carbon atoms of which have a fluorine atom, by reacting a halogenated olefin having at least one carbon—carbon double bond, a carbon atom or the carbon atoms of which bond have a chlorine atom or atoms bound thereto, and, in which the carbon atom or atoms with a single bond in the molecule have no halogen atom other than a fluorine atom, with an alkali metal fluoride, said reaction of the halogenated olefin with the alkali metal fluoride is conducted in the presence of an organic halogen-containing compound having a carbon—carbon single bond, a carbon or the carbons of which have at least one halogen atom other than fluorine atom.
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- Solvents for use in fluorination reactions
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A method of fluorinating an organic compound comprising reacting an organic compound with a fluorinating agent characterized in that a perfluorocarbon compound is present in the reaction medium. The perfluorocarbon compound may replace an amount of a solvent which would otherwise be required for the reaction to proceed efficiently. The perfluorocarbon compound is readily recoverable after reaction and may be re-used in subsequent reactions. Additives to the reaction medium, such as 18-crown-6, may increase the amoun of solvent which may be replaced. The method is beneficial where solvent consumption would otherwise be large, or where solvent recovery would otherwise be difficult.
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- Process for producing fluorinated alkene and fluorinated alkane
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A vic-dichloro-fluorinated alkene of the formula: R1 --CCl=CCl--R2, and a fluorinated alkane of the formula: R1 --CR3 R4 --CR5 R6 --R2, wherein each of R1 and R2 independently represents a perfluoroalkyl group or both of R1 and R2 form together a perfluoroalkylene group, and R3, R4, R5 and R6 independently represent hydrogen or fluorine, are produced from an inexpensive raw material. More specifically, hexachlorocyclopentadiene is reacted with gaseous chlorine using an antimony catalyst, and then the reaction product is reacted with hydrogen fluoride to give 1,2-dichlorohexafluorocyclopentene. Thus-obtained compound is either (i) hydrogenated, or (ii) treated with a fluorinating agent to substitute the chlorine atoms by fluorine atoms, and then hydrogenated, to give the intended fluorinated alkane.
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- Perfluorocarbon fluids as solvent replacements
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Perfluoroperhydrophenanthrene 1 may be used as a 'bulking agent' to minimise the problem of solvent recovery in halogen exchange ('Halex') reactions for the preparation of octafluorocyclopentene 8, and chlorofluoro-pyridine, -pyrimidine and -benzene derivatives. New 'one-pot' procedures for the syntheses of hexafluorobut-2-yne 3, octafluorobut-2-ene 11 and hexafluorocyclobutene 7 are described.
- Chambers, Richard D.,Edwards, Andrew R.
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p. 3623 - 3627
(2007/10/03)
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- Thermal and Photochemistry of Perfluoro-1,6-heptadiene and the Perfluoro-1,3,6-heptatrienes
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Pyrolysis transformed the title diene (1) into a 9:1 mixture of perfluorobicycloheptane (2) and cis-perfluorobicycloheptane (3) at 300 deg C and at >450 deg C principally into perfluorocyclopentene (11).Mercury-sensitized vapor phase photolysis of 1 also yielded 2 and 3, but the latter now dominated and its trans isomer 13 was formed as well.In the presence of nitrogen as a bath gas, the product was further enriched in the isomers.Radical bromination of 1, a model reaction for the triplet photocyclization, gave cis- and trans-perfluoro-1,2-bis(bromomethyl)cyclopentane (16).Configurations were assigned to the cis and trans isomers of perfluoro-1,3,6-heptatriene (19 and 20), and they were equilibrated with iodine/visible light (Kt->c = 1.6(7) in CDCl3, 14 deg C).The cis triene underwent electrocyclization at 133 deg C to perfluoro-3-allylcyclobutene (27); thermal ring opening of this cyclobutene yielded exclusively the cis isomer.At 250 deg C both the cis triene and the allylcyclobutene were transformed quantitatively into perfluorobicyclohept-2-ene (28).Trans triene gave no detectable cyclobutene over a range of temperatures, but yielded the compound at 250 deg C.Ultraviolet irradiation of cis triene produced the allylcyclobutene, and mercury photosensitization of either compound (or the trans triene) proceeded a step farther to give tricycloheptane valence isomers (31 and 32).The internal cycloadditions described here contribute to our knowledge of the ground rules for reactions of this type in unsaturated fluorocarbons.
- Jing, Naiyong,Lemal, David M.
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- Reactions of 1,2,3,4,5-Pentafluorocyclopentadiene
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The synthesis of 1,2,3,4,5-pentafluorocyclopentadiene (2) from 1,2,3,4,5-pentachloro-1,2,3,4,5-pentafluorocyclopentane (1) is closely investigated.Side-products are 1,2,3,4-tetrafluorocyclopentadiene (4) and 5-chloro-1,2,3,4-tetrafluorocyclopentadiene (5).Under UV irradiation, 2 isomerizes to give 1,2,3,5,5-pentafluorocyclopentadiene (6). 2 dimerizes forming a mixture of Diels-Alder products.This dimerisation is irreversible until 700 deg C.The hydrogen in 2 can be replaced by bromine forming 7. 2 adds Cl2, Br2, I2, and carbonylmetal hydrides.Also with the most stable salt Tl(+)C5F5(-) (8) the synthesis of a η5-C5F5 complex was unsuccessful.A modified synthesis of hexafluorocyclopentadiene (12) from hexachlorocyclopentadiene (9) is presented. 12 adds AsF5 forming c-C5F7AsF4 (13).With SbF5 no cation c-C5F5(+) (14) could be detected so far.
- Paprott, Gerhard,Lehmann, Sabine,Seppelt, Konrad
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p. 727 - 734
(2007/10/02)
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- Reactions Involving Fluoride Ion. Part 31. Remarkable Reactivity of Perfluorobicyclobutylidene
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Perfluorobicyclobutylidene (3) readily forms cycloadducts with butadiene, cyclopentadiene, 6,6-dimethylfulvene and furan, whereas perfluoro-3,4-dimethylhex-2-ene (2) is unreactive under the same conditions.This marked difference in reactivity between (2) and (3) is attributed to angle strain in (3).Reaction of the alkene (3) with cylohexa-1,3-diene yields 1H,1'H-perfluorobicyclobutyl (9) and benzene, by hydrogen transfer.The alkene (3) undergoes an 'ene' reaction with propene.Epoxides of perfluorobicyclobutylidene (3) and perfluorobicyclopentylidene (11) have been prepared; they both show high thermal stability and the latter epoxide fragments in the presence of fluoride ion to yield perfluorocyclopentene and perfluorocyclopentanone.
- Bayliff, Andrew E.,Bryce, Martin R.,Chambers, Richard D.,Kirk, Julian R.,Taylor, Graham
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p. 1191 - 1194
(2007/10/02)
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