- Vapor-phase catalytic methylation of 1,1,1,3,3,3-hexafluoroisopropanol for the mass production of 1,1,1,3,3,3-hexafluoroisopropyl methyl ether
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With the phasing-out of chlorofluorocarbons and hydrochlorofluorocarbons required by the Montreal and Kyoto Protocols, hydrofluoroethers (HFEs) are now considered to be promising alternatives due to their zero ozone-depletion and low global-warming potentials, and their significant capacities for use in heat-pump and cleaning-agent applications. However, the pollution-free and large-scale synthesis of HFEs has been a long-standing challenge. To address the issue, we previously reported a novel synthetic method for the large-scale production of 1,1,1,3,3,3-hexafluoroisopropyl methyl ether (HFE-356mmz), a representative HFE, through the vapor-phase methylation of 1,1,1,3,3,3-hexafluoroisopropanol using metal fluorides as catalysts. In this work, mixed oxides of Mg and Al with various Mg/Al2 ratios were employed as alternative catalysts; their abilities to promote the reaction were determined and the methylation mechanism was explored. All Mg-Al mixed oxides promoted the production of HFE-356mmz, albeit with different efficiencies, which were found to be determined by the surface acid-base properties of the catalysts. The results agree well with those obtained using metal fluorides as catalysts and provide new mechanistic evidence. Our study not only offers further evidence of the reaction mechanism, but also affords a more universal and operable process that uses more-common and less-expensive catalysts.
- Li, Wei,Lu, Fengniu,Zhang, Xiaoling
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- Sensory irritation mechanisms investigated from model compounds: Trifluoroethanol, hexafluoroisopropanol and methyl hexafluoroisopropyl ether
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Quantitative structure-activity relationships (QSAR) have suggested the importance of hydrogen bonding in relation to activation of the sensory irritant receptor by nonreactive volatile organic chemicals. To investigate this possibility further, three model compounds with different hydrogen bond acidity, trifluoroethanol, hexafluoroisopropanol and methyl hexafluoroisopropyl ether, were selected for study. The potency of each chemical is obtained from the concentration necessary to reduce respiratory rate in mice by 50% (RD50). The RD50 values obtained were: methyl hexafluoroisopropyl ether (≥ 160,000 ppm), trifluoroethanol (11,400-23,300 ppm), and hexafluoroisopropanol (165 ppm). QSAR showed that trifluoroethanol and methyl hexafluoroisopropyl ether behaved as predicted as nonreactive sensory irritants, whereas hexafluoroisopropanol was much more potent than predicted. The higher than predicted potency of hexafluoroisopropanol could be due to a coupled reaction, involving both strong hydrogen bonding and weak Bronsted acidity. A concerted reaction could thus be more efficient in activation of the receptor. Hydrogen bonding properties and concerted reactions may be important in the activation of the sensory irritant receptor by nonreactive volatile organic chemicals.
- Nielsen, Gunnar D.,Abraham, Michael H.,Hansen, Lea F.,Hammer, Maria,Cooksey, Christopher J.,Andonian-Haftvan, Jenik,Alarie, Yves
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- METHOD FOR PRODUCING FLUORINE-CONTAINING ETHER
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PROBLEM TO BE SOLVED: To provide a method for producing a fluorine-containing ether compound in a safe and efficient manner, in a method for producing a fluorine-containing ether compound using a dialkyl sulfate. SOLUTION: There is provided a method for producing a fluorine-containing ether compound comprising the steps of: (a) reacting a sulfate-forming agent with a first alcohol compound at 50 to 200°C under reduced pressure in a first reactor to generate a gas containing a dialkyl sulfate; and (b) reacting an aqueous solution containing a metal fluorine-containing alkoxide with the dialkyl sulfate generated in the step (a) under reduced pressure in a second reactor to form a fluorine-containing ether compound. SELECTED DRAWING: Figure 1 COPYRIGHT: (C)2020,JPOandINPIT
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Paragraph 0039-0047
(2020/09/02)
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- A novel vapor-phase catalytic synthetic approach for industrial production of 1,1,1,3,3,3-hexafluoroisopropyl methylether
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1,1,1,3,3,3-Hexafluoroisopropylmethyl ether (HFE-356mmz) is an important substitute for chlorofluorocarbons and hydrochlorofluorocarbons due to its zero ozone depletion potential and low global warming potential. However, mass production of HFE-356mmz remains a long-standing challenge. Herein, we applied metal fluorides as catalysts in the methylation of 1,1,1,3,3,3-hexafluoroisopropanol to produce HFE-356mmz for the first time. The catalyst not only improves the synthetic efficiency, but also makes the reaction solvent-free. The pollution-free, recyclable, and continuous synthetic process enables industrial production of HFE-356mmz. To optimize the synthetic efficiency, a series of metal fluorides (AlF3, MgF2, CaF2, SrF2, and BaF2) was used, among which MgF2 exhibited the highest activity. Through careful examination of each metal fluoride, it was found that the activity of the catalyst was determined by co-operative action of the surface acid–base properties and the total amount of surface acid sites. Based on these results, a rational mechanism for the vapor-phase methylation was proposed.
- Li, Wei,Yang, Gang,Lu, Fengniu,Zhang, Xiaoling
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- Method for preparing hydrofluoroether through two-step process
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The invention discloses a method for preparing hydrofluoroether through a two-step process. With the method provided by the invention, p-toluensulfonyl chloride and fluorine-containing alcohol are subjected to a reaction to obtain p-toluenesulfonate, and the p-toluenesulfonate and sodium alkoxide are subjected to a Williamson ether synthetic reaction to obtain the hydrofluoroether. The method disclosed by the invention has the advantages of cheap and low-toxicity raw materials, mild and controllable reaction conditions, and high yield.
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Paragraph 0064; 0066
(2019/07/10)
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- Preparation method of hexafluoroisopropyl methyl ether
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The invention discloses a preparation method of 1,1,1,3,3,3-hexafluoroisopropyl methyl ether. The preparation method includes reacting trifluoroacetate with formate to obtain 1,1,1,3,3,3-hexafluoroisopropanol, and applying a methylation reagent to the 1,1,1,3,3,3-hexafluoroisopropanol to obtain the 1,1,1,3,3,3-hexafluoroisopropyl methyl ether. The preparation method has the advantages that raw materials are cheap and easy to obtain, the preparation process is mild and the method is simple to operate.
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Paragraph 0051-0074
(2019/06/30)
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- Method for synthesizing hexafluoroisopropyl methyl ether
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The invention discloses a method for synthesizing a hexafluoroisopropyl methyl ether. The hexafluoroisopropyl methyl ether is prepared by reacting hexafluoroisopropanol and methyl fluorosulfonate. Theinvention provides a rapid and high-efficiency method for synthesizing the hexafluoroisopropyl methyl ether, by-products in chemical production are taken as methylation reagents, and the method has significances for improving the environmental protection during the chemical production; moreover, the method disclosed by the invention simultaneously has the advantages of being mild in reaction conditions, high in reaction speed, high in reaction yield, high in reaction selectivity and high in product purity.
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Paragraph 0039; 0052; 0054; 0056; 0057; 0058
(2018/11/22)
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- Method for preparing hexafluoroisopropyl methyl ether
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The invention discloses a method for preparing hexafluoroisopropyl methyl ether. The method comprises that in the presence of a catalyst, hexafluoroisopropanol and dimethyl sulfate undergo a reaction to produce hexafluoroisopropyl methyl ether and the catalyst comprises a main catalyst and a cocatalyst according to a mole ratio of 300: 1 to 30: 1. The method has the advantages of appropriate reaction temperature, simple processes, low cost, high reaction yield, high selectivity, high product purity and environmental friendliness.
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Paragraph 0026; 0027
(2017/06/24)
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- Process method for catalytic synthesis of 1,1,1,3,3,3-hexafluoro isopropyl methyl ether
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The present invention relates to a process method for catalytic synthesis of 1,1,1,3,3,3-hexafluoro isopropyl methyl ether, and the method includes the steps of preparation of an alkaline hexafluoroisopropanol solution containing a phase transfer catalyst, preparation of hexafluoro isopropyl methyl ether, distillation and purification and the like. The 1,1,1,3,3,3-hexafluoro isopropyl methyl ether is prepared from dimethyl sulfate and hexafluoroisopropanol as raw materials in an alkaline environment under the effect of a soluble quaternary ammonium salt phase transfer catalyst, and product yield and purity are greatly improved.
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Paragraph 0021-0023
(2017/03/23)
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- Friedel-crafts reaction of benzyl fluorides: Selective activation of C-f bonds as enabled by hydrogen bonding
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A Friedel-Crafts benzylation of arenes with benzyl fluorides has been developed. The reaction produces 1,1-diaryl alkanes in good yield under mild conditions without the need for a transition metal or a strong Lewis acid. A mechanism involving activation of the C-F bond through hydrogen bonding is proposed. This mode of activation enables the selective reaction of benzylic C-F bonds in the presence of other benzylic leaving groups.
- Champagne, Pier Alexandre,Benhassine, Yasmine,Desroches, Justine,Paquin, Jean-Franois
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supporting information
p. 13835 - 13839
(2015/02/05)
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- Activation of alkyl C-F Bonds by B(C6F5)3: Stoichiometric and catalytic transformations
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The Lewis acid B(C6F5)3 is shown to activate a series of alkyl fluorides. In stoichiometric reactions, treatment of sterically demanding phosphines with B(C6F5) 3/alkyl fluorides gives phosphonium fluoroborate salts while treatment of B(C6F5)3/alkyl fluorides with the salts [tBu3PX][XB(C6F5)3] (X = H, PhS) gives the alkane and the salt byproduct [tBu3PX][FB(C 6F5)3]. These fluoroalkanes are also catalytically converted to the corresponding alkanes by reaction of the fluoroalkane and Et3SiH using B(C6F5)3 as the catalyst.
- Caputo, Christopher B.,Stephan, Douglas W.
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scheme or table
p. 27 - 30
(2012/04/10)
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- Preparation of Methyl Fluoroalkyl Ethers
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Methyl fluoroalkyl ether can be produced by the reaction of a fluoroalkyl alcohol with chloromethane. The process involves reacting an alkoxide of a fluoroalkyl alcohol with chloromethane.
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Page/Page column 4
(2010/12/29)
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- NOVEL ALPHA-FLUOROMETHOXYCARBOXYLIC ESTER, PROCESS FOR PRODUCING THE ALPHA-FLUOROMETHOXYCARBOXYLIC ESTER, AND PROCESS FOR PRODUCING SEVOFLURANE
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The present invention provides a novel α-fluoromethoxycarboxylic ester represented by Formula (1): (CF3)2C(OCH2F)COOR wherein R is a hydrocarbon group that may have a substituent; a process for producing 1,1,1,3,3,3-hexafluoroisopropyl fluoromethyl ether, the process including hydrolyzing and decarboxylating the α-fluoromethoxycarboxylic ester; and a process for producing an α-fluoromethoxycarboxylic ester represented by Formula (1): (CF3)2C (OCH2F)COOR, the process including reacting an α-hydroxycarboxylic ester represented by Formula (2): (CF3)2C(OH)COOR with a halofluoromethane in the presence of an alkaline compound. According to the present invention, 1,1,1,3,3,3-hexafluoroisopropyl fluoromethyl ether (sevoflurane), which is known as an anesthetic compound, can be efficiently produced at low cost.
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Page/Page column 4-5
(2010/02/17)
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- NOVEL CARBOXYLIC ACID COMPOUND, USE THEREOF, AND PROCESS FOR PRODUCING THE SAME
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The present invention provides a process for producing 1,1,1,3,3,3-hexafluoro-2-methoxypropane, wherein a novel compound, 2-methoxy-2-trifluoromethyl-3,3,3-trifluoropropionic acid or a salt thereof is decarboxylated, or wherein an olefin compound represented by chemical formula (4): CF2=C(CF3)(OCH3) is reacted with a fluorinating agent; and a process for producing 2-methoxy-2-trifluoromethyl-3,3,3-trifluoropropionic acid or a salt thereof by reacting a hydroxycarboxylic ester with a methylating agent and then hydrolyzing the reaction product, or hydrolyzing the hydroxycarboxylic ester and then reacting the resulting product with a methylating agent. In accordance with the invention, 1,1,1,3,3,3-hexafluoro-2-methoxypropane, which is useful as a raw material for, for example, the anesthetic Sevoflurane, can be produced efficiently and at low cost.
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Page/Page column 12
(2009/03/07)
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- NOVEL ALPHA -FLUOROMETHOXYCARBOXYLIC ESTER, PROCESS FOR PRODUCING THE ALPHA -FLUOROMETHOXYCARBOXYLIC ESTER, AND PROCESS FOR PRODUCING SEVOFLURANE
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The present invention provides a novel α-fluoromethoxycarboxylic ester represented by Formula (1): (CF3)2C(OCH2F)COOR wherein R is a hydrocarbon group that may have a substituent; a process for producing 1,1,1,3,3,3-hexafluoroisopropyl fluoromethyl ether, the process including hydrolyzing and decarboxylating the α-fluoromethoxycarboxylic ester; and a process for producing an α-fluoromethoxycarboxylic ester represented by Formula (1) : (CF3)2C(OCH2F)COOR, the process including reacting an α-hydroxycarboxylic ester represented by Formula (2): (CF3)2C(OH)COOR with a halofluoromethane in the presence of an alkaline compound. According to the present invention, 1,1,1,3,3,3-hexafluoroisopropyl fluoromethyl ether (sevoflurane), which is known as an anesthetic compound, can be efficiently produced at low cost.
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Page/Page column 7-8
(2009/04/23)
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- Hydrogen bonding lowers intrinsic nucleophilicity of solvated nucleophiles
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The relationship between nucleophilicity and the structure/environment of the nucleophile is of fundamental importance in organic chemistry. In this work, we have measured nucleophilicities of a series of substituted alkoxides in the gas phase. The functional group substitutions affect the nucleophiles through ion-dipole, ion-induced dipole interactions and through hydrogen bonding whenever structurally possible. This set of alkoxides serves as an ideal model system for studying nucleophiles under microsolvation settings. Marcus theory was applied to analyze the results. Using Marcus theory, we separate nucleophilicity into two independent components, an intrinsic nucleophilicity and a thermodynamic driving force determined solely by the overall reaction exothermicity. It is found that the apparent nucleophilicities of the substituted alkoxides are always much lower than those of the unsubstituted ones. However, ion-dipole, ion-induced dipole interactions, by themselves, do not significantly affect the intrinsic nucleophilicity; the decrease in the apparent nucleophilicity results from a weaker thermodynamic driving force. On the other hand, hydrogen bonding not only stabilizes the nucleophile but also increases the intrinsic barrier height by 3 to ~4 kcal mol-1. In this regard, the hydrogen bond is not acting as a perturbation in the sense of an external dipole but more directly affects the electronic structure and reactivity of the nucleophilic alkoxide. This finding offers a deeper insight into the solvation effect on nucleophilicity, such as the remarkably lower reactivities in nucleophilic substitution reactions in protic solvents than in aprotic solvents.
- Chen, Xin,Brauman, John I.
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scheme or table
p. 15038 - 15046
(2009/03/12)
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- SYNTHESIS AND TRANSFORMATIONS OF PERFLUORO(2,4-DIMETHYL-3-HEPTENE) OXIDE
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The oxidation of perfluoro(2,4-dimethyl-3-heptene) was realized with aqueous solutions of sodium hypohalites.The reaction of the obtained perfluoro(2,4-dimethyl-3-heptene) oxide with nucleophilic and electrophilic reagents was studied.Attack on the epoxide ring of perfluoro(2,4-dimethyl-3-heptene) oxide is hindered with increase in the size of the nucleophile.Perfluoro(2,4-dimethyl-3-heptene) oxide exhibits high stability toward electrophiles.
- Zapevalov, A. Ya.,Filyakova, T. I.,Kolenko, I. P.,Peschanskii, N. V.,Kodess, M. I.
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p. 2066 - 2071
(2007/10/02)
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