- Preparation method of hexafluorobutadiene
-
The invention relates to a preparation method of hexafluorobutadiene, and belongs to the technical field of fluorine-containing gas preparation. The preparation method comprises the following steps: preparing a polar base solution, activated zinc and 1,2-dichloro2iodo-1,1,2-trifluoroethane, further preparing 1,2,3,4-tetrachlorohexafluorobutane, and finally preparing hexafluorobutadiene. Accordingto the method, activated zinc is used in the preparation process and is matched with a polar base solution serving as a solvent, so that the reaction rate is increased, the yield and selectivity of 1,2,3,4-tetrachlorohexafluorobutane are guaranteed; therefore, the problem that the reaction rate is influenced by using zinc particles which are not activated and have larger particles and adopting a solvent with poorer polarity in the prior art is solved; in addition, a non-polar solvent and activated zinc are added in the preparation of hexafluorobutadiene, so that byproducts generated in the preparation process of hexafluorobutadiene are easier to separate while the yield and selectivity of hexafluorobutadiene are ensured.
- -
-
Paragraph 0039; 0050-0052; 0062; 0063; 0064; 0074; 0075
(2021/01/29)
-
- METHOD FOR PRODUCING HEXAFLUORO-1,3-BUTADIENE
-
Provided is a method for producing hexafluoro-1,3-butadiene, and the method can produce hexafluoro-1,3-butadiene at an industrially sufficient level of yield. In a reaction liquid containing a halogenated butane represented by chemical formula, CF2X1—CFX2—CFX3—CF2X4 (X1, X2, X3, and X4 are each independently a halogen atom other than a fluorine atom), zinc, and an organic solvent, a reaction is conducted to eliminate the halogen atoms other than a fluorine atom, X1, X2, X3, and X4, from the halogenated butane, yielding hexafluoro-1,3-butadiene. During the reaction, the concentration of a zinc halide generated by the reaction, in the reaction liquid is not more than the solubility of the zinc halide in the organic solvent.
- -
-
Paragraph 0051-0062
(2021/02/12)
-
- PRODUCTION METHOD FOR HEXAFLUORO-1,3-BUTADIENE
-
Provided is a method that is for producing hexafluoro-1,3-butadiene, discharges small amounts of industrial wastes, and is industrially applicable. The method for producing hexafluoro-1,3-butadiene includes a reaction step of reacting a halogenated butane represented by chemical formula, CF2X1-CFX2-CFX3-CF2X4 (X1, X2, X3, and X4 are each independently a halogen atom other than a fluorine atom) in an organic solvent in the presence of zinc to eliminate the halogen atoms, X1, X2, X3, and X4, other than the fluorine atoms to generate hexafluoro-1,3-butadiene, giving a reaction product containing the hexafluoro-1,3-butadiene, and an aftertreatment step of separating the hexafluoro-1,3-butadiene from the reaction product produced in the reaction step, then adding water to a reaction product residue after the separating, and removing the organic solvent, giving an aqueous solution of zinc halide.
- -
-
Paragraph 0045-0046
(2021/06/04)
-
- Preparation method of hexafluorobutadiene
-
The invention relates to a preparation method of hexafluorobutadiene, which comprises the following steps: respectively dehydrating a 3, 4-dichlorohexafluoro-1-butene raw material and an organic solvent, adding the dehydrated 3, 4-dichlorohexafluoro-1-butene raw material and the dehydrated organic solvent into a dechlorination reaction kettle together with zinc powder, carrying out a dechlorination reaction to obtain a dechlorination product, and carrying out rectification and catalytic conversion on the dechlorination product to obtain a hexafluorobutadiene product. Compared with the prior art, the method has the advantages that the by-product is rearranged into hexafluorobutadiene by using a catalyst, and rectification purification is combined, so that the purity of the obtained hexafluorobutadiene product is high, the content of impurities such as hexafluoro-2-butyne and hexafluorocyclobutene in the hexafluorobutadiene product is remarkably reduced, the difficulty of downstream production of high-purity hexafluorobutadiene can be reduced, and the purity requirement on 3, 4-dichlorohexafluoro-1-butene raw material is reduced from 99.95% to 99%, the requirement on the purity of the 3, 4-dichlorohexafluoro-1-butene raw material is reduced, the pressure of upstream production and investment is greatly reduced, and the height of a rectifying tower for producing the 3, 4-dichlorohexafluoro-1-butene can be greatly reduced.
- -
-
Paragraph 0043-0066
(2021/07/09)
-
- Preparation method of hexafluoro-1, 3-butadiene
-
The invention belongs to the technical field of organic synthesis, and particularly relates to a preparation method of hexafluoro-1, 3-butadiene. The method comprises the following steps: cracking R22 used as a raw material to prepare TFE, preparing TFE and Br2 according to a certain ratio under certain conditions to generate dibromotetrafluoroethane, and reacting dibromotetrafluoroethane with TFE at certain temperature under the conditions of zinc powder and a DMF-toluene combined solvent to prepare the hexafluoro-1, 3-butadiene. After the reaction, a gas phase sample is collected and analyzed by GC chromatography, and the proportion of hexafluoro-1, 3-butadiene accounts for more than 85%. The method has the advantages of simple and accessible raw materials, low price, simple and safe technical preparation process, high product yield and the like.
- -
-
Paragraph 0029; 0031-0032; 0034-0035; 0037
(2021/04/14)
-
- Study on the pyrolysis characteristics of a series of fluorinated cyclopentenes and implication of their environmental influence
-
3,3,4,4,5,5-hexafluorocyclopentene (6FE), 1,3,3,4,4,5,5-heptafluorocyclopentene (7FE) and octafluorocyclopentene (8FE) are considered as new generation of potential chlorofluorocarbons substitutes. To investigate the thermostabilities, tubular furnace experiments were designed over temperature range of 500-850℃. The results show that 6FE, 7FE and 8FE are all stable below 650 ℃, thus have good stabilities in common storage and practical use condition. Furthermore, considering the short atmospheric lifetimes (several months), low global warming potentials (GWPs, less than 119) and zero ozone depletion potentials (ODPs), the compounds seem no big influences on the climate change.
- Bi, Fang,Gao, Rui,Ji, Yuanyuan,Li, Hong,Li, Ling,Liu, Chenfei,Wang, Xuezhong,Wu, Zhenhai,Yanqin, Ren,Zhang, Hao,Zhang, Xin
-
-
- Synthesis method of halogenated butene
-
The invention discloses a synthesis method of halogenated butene. The method comprises: (1) carrying out a fluorination reaction on hexachlorobutadiene and a fluorination reagent, and purifying the obtained reaction product to obtain fluorochlorobutane; and (2) carrying out a dehalogenation reaction on the fluorochlorobutane and a dehalogenation reagent in a first solvent, and purifying the obtained reaction product to obtain the halogenated butene. The method has the advantages of simple process, less three wastes, high yield, low cost and the like.
- -
-
Paragraph 0066; 0071-0073; 0079-0081; 0087-0088; 0095; 0099
(2020/05/30)
-
- Preparation method of hexafluoro-1,3-butadiene and intermediate thereof
-
The invention discloses a preparation method of hexafluoro-1,3-butadiene and an intermediate thereof, wherein the preparation method of hexafluoro-1,3-butadiene comprises the steps: A1, carrying out areaction on 1,2-dibromo-1-chloro-1,2,2-trifluoroethane with trifluorohaloethylene in a polar aprotic solvent under the action of an initiator, and rectifying and purifying a reaction solution to obtain 1,4-dibromo-2-chloro-3-halo-1,1,2,3,4,4-hexafluorobutane, wherein the structural formula of trifluorohaloethylene is CF2=CFX, X is Cl, Br or I, and the initiator is selected from at least one of azodiisobutyronitrile, di-tert-butyl peroxide, dibenzoyl peroxide, dicumyl peroxide, tert-butyl hydroperoxide, potassium persulfate and ammonium persulfate; and A2, carrying out dehalogenation reactionon 1,4-dibromo-2-chloro-3-halo-1,1,2,3,4,4-hexafluorobutane and zinc powder to obtain hexafluoro-1,3-butadiene. The preparation method has the advantages of simple process, mild reaction conditions, suitability for industrial production and the like.
- -
-
Paragraph 0042; 0048-0073; 0094-0097
(2020/09/30)
-
- PRODUCTION METHOD OF PERFLUOROALKADIENE COMPOUND
-
PROBLEM TO BE SOLVED: To provide a method capable of obtaining a perfluoroalkandiene compound in a high yield while reducing the generation amount of impurities which are difficult to separate. SOLUTION: The production method is a method for producing a perfluoroalkandiene compound represented by the general formula (1): CF2=CF-(CF2)n-4-CF=CF2 (1) [in the formula, n represents an integer of 4 to 20.] and comprises a reaction step of reacting a compound represented by the general formula (2): CF2X1-CFX2-(CF2)n-4-CF2-CF2X3 (2) [in the formula, n is the same as defined above; X1, X2 and X3 are the same or different, X1 and X2 represent a halogen atom, and X3 represents a chlorine atom, a bromine atom or an iodine atom, provided that both X1 and X2 are not fluorine atoms] in the presence of a nitrogen-containing compound and zinc or a zinc alloy in an organic solvent in which the reaction step includes a mixing step of sequentially mixing a solution including zinc or a zinc alloy and an organic solvent, a nitrogen-containing compound and the compound represented by the general formula (2). SELECTED DRAWING: None COPYRIGHT: (C)2021,JPOandINPIT
- -
-
Paragraph 0046; 0056-0058
(2021/01/15)
-
- Direct Transformation of Tetrafluoroethylene to Trifluorovinylzinc via sp2C-F Bond Activation
-
Trifluorovinylzinc is a common synthetic intermediate for trifluorovinyl derivatives, including α,β,β-trifluorostyrenes and hexafluorobutadiene. Here, we report a novel synthetic approach for the formation of trifluorovinylzinc chloride via a C-F bond activation of tetrafluoroethylene (TFE), which is an industrially cost-effective bulk feedstock with a negligible GWP. The present system provides a practical synthetic route to various trifluorovinyl derivatives with very low energy consumption.
- Kikushima, Kotaro,Etou, Yuusuke,Kamura, Ryohei,Takeda, Ippei,Ito, Hideki,Ohashi, Masato,Ogoshi, Sensuke
-
supporting information
p. 8167 - 8172
(2020/11/02)
-
- Method for preparing perfluoroalkadiene and perfluoroalkyne by gas-phase isomerization (by machine translation)
-
The invention relates to a method for preparing perfluorinated alkadiene and perfluorinated alkyne by gas phase isomerization. According to the method, perfluorinated cycloolefin is utilized as a rawmaterial, gas phase isomerization reaction happens under the existence of an isomerization catalyst to obtain the perfluorinated alkadiene and the perfluorinated alkyne. According to the method disclosed by the invention, the isomerization catalyst has cheap price; furthermore, the perfluorinated alkadiene or the perfluorinated alkyne can be synthesized at a high conversion rate and at a high selectivity by controlling a reaction temperature; the method is suitable for large-scale gas phase reaction to prepare the perfluorinated alkadiene and the perfluorinated alkyne and is especially suitable for large-scale gas phase reaction to prepare hexafluoro-1,3-butadiene and octafluoro-1,3-pentadiene.
- -
-
Paragraph 0048; 0049
(2020/06/05)
-
- Preparation method of hexafluorobutadiene
-
The invention belongs to the technical field of organic chemistry, particularly relates to a preparation method of hexafluorobutadiene, and provides a preparation method of hexafluorobutadiene. The method comprises the following steps: in an inert atmosphere, carrying out a reaction on 1,1-dibromotetrafluoroethane as a raw material and zinc powder in an aprotic polar solvent in the presence of aluminum trihalide to generate an organic zinc reagent; and then reacting with trifluorobromoethylene under the action of a palladium catalyst to generate hexafluorobutadiene. The invention discloses a preparation method of hexafluorobutadiene, wherein the preparation method can effectively overcome the technical defects of complex synthesis method and high waste generation tendency in the existing hexafluorobutadiene preparation method.
- -
-
Paragraph 0026-0040
(2020/06/09)
-
- Method for synthesizing high-purity hexafluoro-1, 3-butadiene
-
The invention relates to a method for synthesizing high-purity hexafluoro-1, 3-butadiene, and belongs to the field of organic chemical synthesis. The method for synthesizing the hexafluoro-1, 3-butadieneI is characterized by comprising: heating hexachlorobenzene, chlorine and anhydrous hydrogen fluoride under the action of a catalyst to generate 1, 2-dichloro-3, 3, 4, 4, 5, 5, 6, 6-octafluorocyclohexene; heating the 1, 2-dichloro-3, 3, 4, 4, 5, 5, 6, 6-octafluorocyclohexene and a solvent under the action of a strong oxidant to generate 1, 6-octafluoroadipic acid; and finally, heating the 1, 6-octafluoroadipic acid and a solvent under the action of sodium hydroxide to generate sodium fluoride, water, carbon dioxide and hexafluoro-1, 3-butadiene, performing water removal and carbon dioxide removal treatment on the mixed gas to obtain the high-purity hexafluoro-1, 3-butadiene. The raw materials are cheap and convenient to obtain; the catalyst has good stability and long service life; theproduct separation and purification are simple; and industrial production is easy.
- -
-
Paragraph 0024; 0027; 0033; 0034; 0040
(2020/05/18)
-
- Method for preparing hexafluorobutadiene
-
The invention discloses a method for preparing hexafluorobutadiene. The method is realized by carrying out a coupling reaction between trifluorobromoethylene and trifluorovinyl zinc bromide under theaction of a composite catalyst containing a transition metal compound and an organic phosphorus compound. The provided preparation method has the advantages of high reaction yield, low raw material cost, small amount of three wastes, simple process, mild reaction conditions, and simple process operation.
- -
-
Paragraph 0012; 0036-0075
(2020/07/12)
-
- METHOD FOR FLUORINATING PERCHLORINATED COMPOUNDS
-
The present invention relates to a method for preparing a polyinsaturated perfluorinated compound B from a polyinsaturated perhalogenated compound D having the formula CnX2(n?m+1), in which X is independently selected from one of the halogens, F, Cl, Br or I, provided at least one X is not fluorine; n is the number of carbon atoms and is at least higher than or equal to 4, m is the number of double carbon-carbon bonds and is higher than or equal to 2, wherein the method comprises a step in which compound D is fluorinated in the presence of a fluorinating agent of general formula AFp, in which A is hydrogen, an alkali metal or an alkaline earth metal, and p is 1 or 2, and in the presence of an aprotic organic polar solvent; the method being carried out with a molar ratio of AFp to compound D of less than 1.45*2(n?m+1).
- -
-
Paragraph 0044-0048
(2019/04/29)
-
- Method for preparing hexafluorobutadiene from iodine and chlorine
-
The invention relates to a method for preparing hexafluorobutadiene from iodine and chlorine. The method comprises the following steps: preparing a metal coordinated ionic liquid solvent, and reacting iodine with chlorine to prepare iodine monochloride; reacting iodine monochloride with chlorotrifluoroethylene in the presence of the metal coordinated ionic liquid solvent to prepare 1,2-dichloro-2-iodo-1,1,2-trifluoroethane; carrying out a reaction on the 1,2-dichloro-2-iodo-1,1,2-trifluoroethane in the presence of the metal coordinated ionic liquid solvent under the catalysis of zinc powder to obtain 1,2,3,4-tetrachloro-1,1,2,3,4,4-hexafluorobutane; and reacting the 1,2,3,4-tetrachloro-1,1,2,3,4,4-hexafluorobutane with zinc powder in the presence of the metal coordinated ionic liquid solvent to generate hexafluorobutadiene.
- -
-
Paragraph 0040-0041; 0051-0052; 0062-0063; 0074
(2017/08/27)
-
- A synthetic refrigeration working group ethylene group compound (by machine translation)
-
The invention relates to a synthetic refrigeration working group ethylene group compounds, is 1, 1 - dibromo - 1, 2, 2, 2 - tetrafluoroethane as raw materials, in under the action of the metal or metal compound, to obtain corresponding trifluorovinyl metal complex. This trifluoro vinyl metal complex in the catalyst and the like with the active substances under the action of the coupling reaction, containing the trifluoro ethylene group compound. The method of the invention easy availability of raw materials, the method is simple, the production safety, is a suitable for industrial production method. (by machine translation)
- -
-
Paragraph 0027; 0028
(2017/07/21)
-
- A synthetic hexafluoro - 1, 3 - butadiene method (by machine translation)
-
The invention relates to a method for synthesizing hexafluoro-1,3-butadiene, and belongs to the field of organic chemistry synthesis. The method for synthesizing hexafluoro-1,3-butadiene comprises the following steps: removing hydrogen fluoride from tetrafluoro ethane (HFC-134a) under the action of a catalyst to generate trifluoroethylene; rapidly reacting trifluoroethylene with liquid bromine to generate 1,2-dibromo-1,1,2-trifluoroethane, and removing hydrogen bromide under alkaline conditions to obtain trifluorobromoethylene; and reacting trifluorobromoethylene with activated zinc powder and N,N-dimethyl formamide to generate trifluorovinylzinc, and carrying out a coupling reaction on trifluorovinylzinc under the action of Fe to generate hexafluoro-1,3-butadiene. A solvent can be recovered after above reactions. The method has the advantages of low price and convenient source of raw materials, good stability and long service of the catalyst, simple separation and purification of the above product, and easy industrial production.
- -
-
Paragraph 0039
(2017/09/26)
-
- Method for preparing hexafluoro-1,3-butadiene
-
The invention relates to a method for preparing hexafluoro-1,3-butadiene. The method comprises the following steps: performing reduction dechloridation on 1,2-dichloro-1,1,-2-halothane with zinc powder to obtain a CF2=CHF gas phase intermediate product, introducing into liquid bromine to carry out an addition reaction, and obtaining CBrF2CHBrF; evaporating CBrF2CHBrF in an evaporator to generate a gas, and using a reaction tube filled with a first catalyst to remove one molecule HBr and generate trifluorovinyl bromide; performing two steps of reactions on the trifluorovinyl bromide under the action of the zinc powder, the solvent and a second catalyst, thereby obtaining the hexafluoro-1,3-butadiene. The method has the advantages of being simple in process, high in yield, easy in raw material obtaining, easy in industrialization, green and environment-friendly.
- -
-
Paragraph 0065; 0066; 0067; 0068
(2017/08/27)
-
- A synthetic hexafluoro -1,3-butadiene method
-
The invention relates to a method for synthesizing hexafluoro-1,3-butadiene, and belongs to the field of organic chemistry synthesis. The method comprises the following steps: carrying out gas phase bromination on tetrafluoroethane HFC-134a to generate dibromotetrafluoroethane CF3CBr2F, and carrying out a coupling reaction on dibromotetrafluoroethane, activated zinc powder and N,N-dimethyl formamide under the action of Fe to generate hexafluoro-1,3-butadiene. A solvent after the above reactions can be recycled. The method has the advantages of low price and convenient source of raw materials, high product yield, simple separation and purification of the above product, and easy industrial production.
- -
-
Paragraph 0034; 0037; 0038; 0042
(2018/02/04)
-
- Preparation method of perfluoro butadiene
-
The invention discloses a preparation method of a perfluoro butadiene. Firstly under the action of an initiator, trifiuorobromoethylene is reacted with zinc powder to obtain a reaction solution containing a trifiuorobromoethylene zinc reagent. Then the reaction solution is reacted with a coupling agent to obtain the perfluoro butadiene. The method has the advantages of mild reaction conditions, simple operation, high productivity, less three wastes, low production cost and high product yield.
- -
-
Paragraph 0011; 0028
(2017/03/18)
-
- Method for preparing hexafluorobutadiene
-
The invention discloses a method for preparing hexafluorobutadiene. The method comprises the following steps: carrying out a hydrogenation dechlorination dimerization reaction on 1,1-dichloro-1,2,2-trifluoroethane or 1,2-dichloro-1,1,2-trifluoroethane on a supported metal catalyst in H2 atmosphere, separating out a target product hexafluorobutadiene, carrying out gas phase thermal cracking on an intermediate hydroflurochlorobutane to remove HCl in order to prepare hexafluorobutadiene, filtering the product generated after above reactions, washing the filtered product with an alkali, washing the washed product with water, drying the product, compressing, and carrying out rectifying purification to obtain the highly pure hexafluorobutadiene. The method for preparing hexafluorobutadiene overcomes the disadvantages of long operating period, low unit volume output and large device investment of present technologies, and has the advantages of high yield, few steps, easy industrialization, realization of production of the highly pure hexafluorobutadiene through selection of reactants and control of reaction conditions, simple process, cheap and easily available raw material, low cost, facilitation of industrial production, continuous production, and great improvement of the unit device productivity.
- -
-
Page/Page column 0026
(2017/02/23)
-
- Halogenated fluorine-containing zinc compound alkenylsilane (cyclometallized)
-
The purpose of the present invention is to provide a method for easily producing a fluorine-containing (cyclo)alkenyl zinc halide compound at low cost. The present invention provides a method for producing a fluorine-containing (cyclo)alkenyl zinc halide compound represented by formula (1) (wherein A1 represents a perfluoroalkyl group having 1-12 carbon atoms, or a fluorine atom; A2 represents a fluorine atom or a hydrogen atom; A3 represents a fluorine atom or a hydrogen atom, or alternatively A3 and A1 or A2 may combine together to form a perfluoroalkylene chain having 1-12 carbon atoms; and X' represents a halogen atom), which comprises a step wherein a fluorine-containing olefin represented by formula (2) (wherein X represents a fluorine atom or a chlorine atom; and the other symbols are as defined above) is reacted with a zinc halide represented by formula ZnX'2 (wherein the symbol is as defined above) in the presence of one or more metals that are selected from among magnesium and magnesium alloys.
- -
-
Paragraph 0129
(2017/06/02)
-
- Method of manufacturing hexafluorotitanic -1, 3-butadiene
-
PROBLEM TO BE SOLVED: To provide a method for producing hexafluoro-1,3-butadiene easily, inexpensively and in a high yield. SOLUTION: Hexafluoro-1,3-butadiene is produced from tetrafluoroethylene in the presence of a transition metal catalyst using an organometallic compound. Then the produced hexafluoro-1,3-butadiene may be purified by distillation. COPYRIGHT: (C)2012,JPOandINPIT
- -
-
Paragraph 0004; 0087
(2017/01/02)
-
- PROCESS FOR PRODUCING HEXAFLUORO-1,3-BUTADIENE
-
Disclosed is a process for producing hexafluoro-1,3-butadiene, which is used for an etching gas capable of being used in fine processing for semiconductors, safely in industrialization and at low cost economically. Specifically disclosed is a process for producing hexafluoro-1,3-butadiene comprises (1) a step comprising allowing a compound having four carbon atoms each which bonds to an atom selected from the group consisting of a bromine atom, an iodine atom and a chlorine atom, to react with a fluorine gas in the presence of a diluting gas in a gas phase, thereby preparing a mixture containing a product (A), and (2) a step comprising eliminating halogens excluding a fluorine atom with a metal from the product (A) prepared in the step (1) in the presence of a solvent, thereby preparing a mixture containing hexafluoro-1,3-butadiene.
- -
-
Page/Page column 6
(2009/09/07)
-
- PROCESS FOR THE SYNTHESIS OF PERFLUOROBUTADIENE
-
Process for preparing perfluoro-1,3-butadiene, comprising the following steps : A) preparation of fluoro-halo-butanes of formula : CF2 YI-CFYIICFYIICF2 YI (V) in which YI and YII which may be identical or different, may be H, C1 or Br, with the condition that YI and YII are not simultaneously hydrogen; starting with a chloroolefin having the formula : CY'Y = CY'C1 (II) in which Y, Y', Y', which may be identical or different, are H, C1 or Br, with the condition that Y, Y', Y' are not simultaneously hydrogen; and performing the following steps : - a fluorodimerization, and - a fluorination with elemental fluorine, the order of the two steps also possibly being inverted, - a dehalogenation or dehydrohalogenation step being performed between the two steps, B) dehalogenation or dehydrohalogenation of the fluoro-halo compounds of formula (V) to give the compound perfluoro-1,3-butadiene.
- -
-
Page/Page column 11-12
(2009/09/04)
-
- Method of preparing perfluoroalkadiene
-
Disclosed herein is a method of preparing a perfluoroalkadiene. A dihaloperfluorocarbon used as a starting material is added dropwise to a nonpolar organic solvent, a metal powder and an organic metal compound. The dihaloperfluorocarbon is slowly added dropwise in a temperature range from 30° C. to 150° C. for a certain period of time. Moreover, the nonpolar organic solvent used may be benzene, toluene, xylene, etc., and the organic metal compound is used by being dissolved in ethyl ether or tetrahydrofuran at a concentration of 1 to 3M. The metal powder used may be Mg, Zn, Cd, etc.
- -
-
Page/Page column 3
(2009/04/24)
-
- A general method for nearly reduction-free dehalogenations in a fluorinated biphasic system
-
We have studied the dehalogenations of halofluorinated alkanes and fluorinated ethers, both linear and cyclic, as well as halofluorinated alkanes containing an aromatic moiety, to their corresponding unsaturated species in a biphase fluorinated/hydrogenated solvent system. The reactions in the biphase system lead to higher selectivities and better yields than those obtained performing the reaction in the traditional hydrogenated monophasic system. By this method, the concentrations of hydrogenated by-products of general formula R-CF2H or RCFHR' are as low as 100 ppm. This novel biphasic system provides therefore a useful synthetic route to materials and chemicals for electronics, optical polymers, plasma etching, etc. which require a very high purity of all compounds involved.
- Wlassics,Tortelli
-
p. 359 - 365
(2008/12/22)
-
- Coupling reactions of chlorofluoro and perfluoroalkyl iodides
-
Coupling reactions of chlorofluoro- and perfluoroalkyl iodides R f-I with Rf = ClCF2CFCl-(CF2) 3CF2-, ClCF2CFClO(CF2) 3CF2-, ClCF2CFCl-, (CF3) 2CF- , (CF3)2CFCF2CF2- in the presence of a zinc/solvent system give dimers in good yields. Both homodimerizations (one iodide) and heterodimerizations (two different iodides) have been studied. The effect of temperature and solvent is shown. The zinc mediated dechlorination of vicinal chlorine atoms in the dimers afforded terminal alkenes and dienes.
- Wlassics, Ivan,Tortelli, Vito
-
scheme or table
p. 1719 - 1728
(2009/06/05)
-
- Coupling routes to hexafluoro-1,3-butadiene, substituted-1,3-fluorine-containing butadienes and fluorinated polyenes
-
Hexafluoro-1,3-butadiene was readily prepared via a variety of self-coupling processes, such as Cu(0) mediated self-coupling of iodotrifluoroethene, Pd(0) catalyzed coupling of iodotrifluoroethene with the trifluorovinylzinc reagent, and CuBr2 mediated coupling of the trifluorovinylzinc reagent. Perfluoro-2,3-dimethyl-1,3-butadiene was readily synthesized by the reaction of pentafluoropropenyl-2-zinc reagent with either CuBr2 or FeCl3. Alternatively, perfluoro-2,3-dimethyl-1,3-butadiene was prepared by oxidation of the pentafluoropropenyl-2-copper reagent with dioxygen. Cu(0) mediated coupling of an (E)-substituted α,β-difluoro-β-iodostyrene provided the first useful route to a (Z)(Z)-1,4-diaryl-1,3-tetrafluorobutadiene. Extension of the Cu(0) mediated coupling methodology to a perfluorodienyl iodide demonstrated a useful stereospecific route to perfluoropolyenes.
- Burton, Donald J.,Hansen, Steven W.,Morken, Peter A.,MacNeil, Kathryn J.,Davis, Charles R.,Xue, Ling
-
p. 435 - 442
(2008/12/22)
-
- Preparative-scale one-pot syntheses of hexafluoro-1,3-butadiene
-
Hexafluoro-1,3-butadiene, with its negligible global warming potential, is required in quantities for application in plasma dielectric etching in semiconductor industry and as gaseous microbubble suspension contrast agents in diagnostic ultrasound imaging. Three efficient protocols for the preparation of perfluoro-1,3-butadiene in 62-70% overall yields have been described. They involve the coupling of (1) iodotrifluoroethylene (ITFE) with activated copper, (2) trifluorovinylzinc bromide in the presence of copper (II) or iron (III) salts and (3) trifluorovinylzinc chloride, prepared from 1,1,1,2-tetrafluorethane (HFC 134a) in the presence of copper (II) or iron (III) salts.
- Ramachandran, P. Veeraraghavan,Reddy, G. Venkat
-
p. 443 - 446
(2008/12/21)
-
- CHEMICAL PRODUCTION PROCESSES AND SYSTEMS
-
Chemical production processes are provided that include reacting a metal comprising olefin to form a conjugated olefin; reacting a heterohalogenated olefin to form a conjugated olefin; reacting a halogenated alkane to form a conjugated olefin; and/or reacting a hydrohalogenated olefin to form a conjugated olefin. Chemical production systems are also provided that can include: a first reactant reservoir configured to house a perhalogenated olefin; a second reactant reservoir configured to house a catalyst mixture; a first reactor coupled to both the first and second reservoirs, the first reactor configured to house a metal-comprising mixture and receive both the perhaloganated olefin form the first reactant reservoir and the reactant mixture from the second reactant reservoir; and a product collection reservoir coupled to the first reactor and configured to house a conjugated olefin.
- -
-
Page/Page column 7; 8; 10; 11
(2008/06/13)
-
- Dehalogenation process
-
A process for obtaining vinyl compounds by dehalogenation of halofluorinated compounds having a linear, branched or cyclic structure, said halofluorinated compounds containing in the molecule at least one group: wherein Y1 and Y2, equal to or different from each other, are selected from Cl, Br, I; wherein the halofluorinated compounds are dehalogenated in the presence of a transition metal, or of transition metal couples, by operating in a biphasic system of solvents immiscible among each other, formed of a (per)fluorinated solvent and a dipolar aprotic or protic solvent (co-solvent), wherein the ratio moles co-solvent/equivalents of the halofluorinated compound ranges from 0.5 to 10, preferably from 0.5 to 5, still more preferably from 1 to 3.
- -
-
Page/Page column 5; 6; 11
(2008/06/13)
-
- Dehalogenation process
-
A process for obtaining vinyl compounds by dehalogenation of halofluorinated compounds having a linear, branched or cyclic structure, said halofluorinated compounds containing in the molecule at least one group: wherein Y1 and Y2, equal to or different from each other, are selected from Cl, Br, I; wherein the halofluorinated compounds are dehalogenated in the presence of a transition metal, or of transition metal couples, by operating in a biphasic system of solvents immiscible among each other, formed of a (per)fluorinated solvent and a dipolar aprotic or protic solvent (co-solvent), wherein the ratio moles co-solvent/equivalents of the halofluorinated compound ranges from 0.5 to 10, preferably from 0.5 to 5, still more preferably from 1 to 3.
- -
-
Page/Page column 4
(2008/06/13)
-
- Synthesis of 1,2,3,4-tetrachlorohexafluorobutane
-
The condensation of 1-iodo-1,2,2-trifluoro-1,2-dichloroethane induced by granulated Zn in the presence of catalytic amounts of AcOEt without a solvent results in 1,2,3,4-tetrachlorohexafluorobutane in high yield.
- Karimova,Glazkov,Ignatenko,Mysova
-
p. 2336 - 2337
(2007/10/03)
-
- Process for production of perfluoroalkadienes
-
A process for preparing a perfluoroalkadiene compound of formula (I) CF2═CF—(CF2)n?4—CF═CF2??(I) (wherein n is an integer from 4 to 20) by the deiodofluorination of a compound of formula (II) I—(CF2)n—I??(II) (wherein n is as defined above), characterised in that said deiodofluorination is conducted in the presence of metallic zinc and a nitrogen-containing organic compound.
- -
-
-
- IR Multiphoton Dissociation Dynamics of Octafluorocyclopentene: Time-Resolved Observation of Concerted Products :CF2 and Hexafluorobutadiene
-
Real time observation of :CF2 and hexafluorobutadiene (HFBD) generated simultaneously in the concerted IR multiphoton dissociation of octafluorocyclopentene (OFCP) is reported.The formation rate of both the transients, i.e., hot HFBD and :CF2, which have an overlapping absorption at 250 nm, fits to a single exponential, with a rate constant (2.0 +/- 0.1) x 106s-1.The fast exponential decay of the transient signal up to 100 μs is assigned to electrocyclic isomerization of HFBD to hexafluorocyclobutene with a rate constant k = (5.7 +/- 0.2) x 104s-1, whereas the slower decay on the millisecond time scale suggests :CF2 dimerization to form C2F4, with a bimolecular rate constant (4.5 +/- 0.1) x 107M-1s-1.RRKM calculation for the unimolecular dissociation of OFCP and isomerization of HFBD gives an average energy of OFCP as 383 +/- 10kJ/mol and of nascent HFBD as 202 +/- 5 kJ/mol, corresponding to the experimental rates.The nascent vibrationally hot HFBD exhibits a red shift of 50 nm in the transient absorption spectrum.
- Chowdhury, P. K.
-
p. 12084 - 12089
(2007/10/02)
-
- Thermal reactions of hexafluoro-1,3-butadiene. Part II. Synthesis and thermal transformations of C12F18 trimers
-
Hexafluoro-1,3-butadiene reacts at >/=150 deg C with its cyclodimers containing trifluorovinyl groups to give all the trimers expected for - and -cycloadditions.The ratios of the products formed depend on the temperature and are determined by the stabilities of the dimers and trimers concerned.All those trimers which contain a cyclobutane moiety take part in thermal transformations, such as ring expansion, dimerization and retrocycloaddition reactions.Hexafluoro-1,3-butadiene and its dimers, which are formed in retrocycloaddition reactions, undergo secondary thermal transformations.The latter include the previously unknown insertion of a hexafluorobutadiene molecule into the four-membered ring of one of the dimers.
- Kazmina, Nataliya B.,Mysov, Evgeni I.,Leites, Larisa A.,Bukalov, Sergei S.
-
-
- Thermal reactions of hexafluorobutadiene and hexafluorocyclobutene with elemental sulphur
-
Hexafluorobuta-1,3-diene and hexafluorocyclobutene interact with elemental sulphur under conditions of mutual conversion (>/= 280 deg C) to give the same products, hexafluoro-3,6-dihydro-1,2-dithiine (1), hexafluorothiolene-3 (2) and hexafluorothiolanethione (3).The product composition and ratio depend on the reaction conditions.Dithiine 1 and thiolene 2 were formed in competitive reactions.Their thermal stability and the retrocycloaddition reaction of dithiine 1 have been studied.The latter reaction results in thiolene 2 in addition to the formation of hexafluorocyclobutene.This is consistent with a stepwise mechanism for the retrocycloaddition as well as the cycloaddition reaction.
- Kazmina, N. B.,Mysov, E. I.,Aerov, A. F.,Kagramanova, E. M.
-
p. 203 - 208
(2007/10/02)
-
- Real Time Optical Observation of Nascent Hexafluorobutadiene in the IR Multiphoton Dissociation of Decafluorocyclohexene
-
Real time observation of retro-Diels-Alder dissociation of decafluorocyclohexene into tetrafluoroethylene and hexafluorobutadiene induced by transversely excited atmospheric pulsed CO2 laser is reported.The formation rate and the red-shifted absorption spectra of nascent hexafluorobutadiene suggest substantial internal energy incorporation, which appears to be sufficient for its undergoing electrolytic transformation to hexafluorocyclobutene at a rate corresponding to the decay kinetics.When the above IR multiphoton dissociation of decafluorocyclohexene occurs in presence of oxygen, UV light emission due to COF2* is observed.
- Chowdhury, Pradyot Kumar
-
p. 3455 - 3461
(2007/10/02)
-
- Process for the synthesis of perfluoroalkandienes
-
Perfluorobutadiene and higher alkandienes, with terminal double bonds, are obtained from α,ω-dibromo, α, ω,bromo, iodo perfluoroalkanes by dehalofluorination carried out with the aid of an organometallic compounds, in the presence of aprotic solvent belonging to the class of hydrocarbons or polar aprotic solvent belonging to the class of ethers, with limited reaction times.
- -
-
-
- Broadband Transient Infrared Laser Spectroscopy of Trifluorovinyl Radical, C2F3: Experimental and ab Initio Results
-
The trifluorovinyl radical (C2F3) is identified by using infrared spetroscopy.Real-time broadband infrared laser and diode infrared laser absorption spectra of the trifluorovinyl radical were measured.The radical was generated from UV laser photolysis of trifluoroiodoethene(C2F3I) at248 nm in the gas phase.The observed vibrational frequencies and intensities 2, 1290 (+/- 5) cm-1, 106 (+/- 39) km mol-1; and ν3, 1225 (+/- 5) cm-1, 119 (+/- 41) km mol-1> are in good agreement with ab initio values calculated in this work.Pseudo-first-order decay kinetics of the transient vibrational bands were observed.Analysis of the photoproducts with Fourier transform infrared spectroscopy showed that 1,3-hexafluorobutadiene (C4F6) was present in high concentration.It was probably formed from the reaction of trifluorovinyl radical with trifluoroiodoethene, as is consistent with the observed kinetics.
- Wurfel, Brent E.,Pugliano, Nick,Bradforth, Stephen E.,Saykally, Richard J.,Pimentel, George C.
-
p. 2932 - 2937
(2007/10/02)
-
- ADDITION OF 1-IODO-1,2-DIFLUORO-1,2,2-TRICHLOROETHANE AND 1-IODO-1,2,2-TRIFLUORO-1,2-DICHLOROETHANE TO TRIFLUOROCHLOROETHENE AND 1,2-DIFLUOROCHLOROETHENE
-
It was shown that the addition of 1-iodo-1,2-difluoro-1,2,2-trichloroethane to trifluorochloroethene and also the addition of 1-iodo-1,2-difluoro-1,2,2-trichloroethane and 1-iodo-1,2,2-trifluoro-1,2-dichloroethane to 1,2-difluorochloroethene lead to the formation of mixtures of telomers. 1-Chloro- and 1,4-dichloroperfluorobutadiene and 1,6-dichloroperfluorohexatriene were obtained from polyhalogenobutanes and hexanes by successive dehydrohalogenation, chlorination, and dechlorination.It was shown that 1,1,2,3,4-pentafluoropentachlorobutane and 1,1,2,3,4,5,6-heptafluoroheptachlorohexane form α-aryl-ω-chloroperfluoropolyenes in reaction with arylmagnesium bromides.
- Kremlev, M. M.,Cherednichenko, P. G.,Moklyachuk, L. I.,Yagupol'skii, L. M.
-
p. 2316 - 2320
(2007/10/02)
-
- Process for the synthesis of perfluoroalkandienes
-
Perfluorobutadiene and higher alkandienes, with terminal double bonds, are obtained from α,ω-dibromo or α,ω-bromo iodo per-fluoroalkanes by dehalofluorination carried out at limited reaction times by means of an organometallic compound in the presence of an aprotic solvent selected from the class of hyd-rocarbons or a polar aprotic solvent selected from the class of ethers.
- -
-
-
- Infrared Multiphoton-Induced Concerted :CF2 Elimination in Octafluorocyclopentene by a Pulsed CO2 Laser
-
On infrared multiphoton excitation, octafluorocyclopentene (OFCP) undergoes a ring-opening reaction to give difluorocarbene and hexafluorobutadiene as unstable primary products which undergo further reactions; the former dimerizes to tetrafluoroethylene, and the latter isomerizes to its thermodynamically stable cyclic isomer.The multiphoton dissociation (MPD) yield of OFCP shows a strong fluence dependence, with a threshold of 0.3 J/cm2 for the 10R(32) line of the CO2 laser for inducing the reaction.Two characteristic peaks in the MPD spectra have been observed, both red-shifted from the ν20 ring deformation mode absorption peak of OFCP.Increase in pressure of OFCP or foreign gas addition has shown to deteriorate the MPD yield.
- Chowdhury, Pradyot K.,RAO, K. V. S. Rama,Mittal, J. P.
-
p. 2877 - 2882
(2007/10/02)
-
- ADDITION OF 1,2-DIBROMO-1-CHLOROTRIFLUOROETHANE TO CHLOROTRIFLUOROETHYLENE INDUCED BY UV-RADIATION. SYNTHESIS OF PERFLUORO-1,3-BUTADIENE AND PERFLUORO-1,3,5-HEXATRIENE
-
Photochemically initiated reaction of 1,2-dibromo-1-chlorotrifluoroethane (II) with chlorotrifluoroethylene (I) gave 38percent 1,4-dibromo-2,3-dichlorohexafluorobutane (III) and 19percent 1,6-dibromo-2,3,5-trichlorononafluorohexane (IV) in addition to the higher telomers.Dehalogenations of III and IV yielded perfluoro-1,3-butadiene (VI) and perfluoro-1,3,5-hexatriene (VIII) with 3-chlorononafluoro-1,5-hexadiene (VII), respectively.Photochemical reduction of butane III with 2-propanol resulted in a preferential reduction of C-Br bonds, and from 2,3-dichloro-1,1,2,3,4,4-hexafluorobutane (IX) thus formed, esters of difluoroacetic acid were prepared by dehalogenation of IX and subsequent oxidation and esterification of the product.The photochemical reduction of hexane IV gave a mixture of 79percent trichlorononafluorohexane XII and 21percent dichlorononafluorohexane XIII.The mechanism of formation of the unusual products of the title addition reaction is discussed.
- Dedek, V.,Chvatal, Z.
-
p. 363 - 380
(2007/10/02)
-
