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EP-4011856-B1 - METHOD FOR PURIFYING PHOSPHORUS-CONTAINING OLEFIN COMPOUND SALT AND METHOD FOR PRODUCING OLEFIN COMPOUND USING PURIFIED PRODUCT OBTAINED THEREBY

EP4011856B1EP 4011856 B1EP4011856 B1EP 4011856B1EP-4011856-B1

Inventors

  • ITO, Yuuko
  • NAKAUE, Tsubasa
  • CHAKI, TAKEHIRO
  • USUI, TAKASHI
  • IWAMOTO, TOMOYUKI
  • KUSHIDA, Megumi

Dates

Publication Date
20260506
Application Date
20200804

Claims (8)

  1. A method for purifying a phosphorus-containing olefin compound salt, comprising reprecipitating and/or recrystallizing a solid comprising at least one phosphorus-containing olefin compound salt of formula (1) or (2): wherein X 1 , X 2 each independently are H,F, Cl, Br or I; Y is H, F, Cl, Br, I, alkyl, alkyl ether, fluoroalkyl or fluoroalkyl ether wherein the alkyl is linear or has a side chain or is cyclic and may also have one or two or more substituents containing an atom other than C and H and/or may contain one or two or more atoms other than C and H in the chain structure or the cyclic structure; W + each independently is a monovalent cation comprising PR 3 or P(OR) 3 , wherein R each independently are groups having a saturated or unsaturated structure containing C and H, are optionally bonded together to form a ring, and optionally contain an atom other than C and H; and M - is a boron fluoride anion; in a solvent, thereby obtaining a purified product of the phosphorus-containing olefin compound salt, wherein after the solid is dissolved in a solvent at 45-60°C, the temperature of a solution is reduced at -0.25°C/min or less to thereby perform reprecipitation and/or recrystallization.
  2. The method of claim 1, wherein the solvent is at least one of ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, methanol, ethanol, propanol, isopropanol, and butanol.
  3. The method of claim 1 or 2, further comprising extracting the purified product by suction filtration and/or pressure filtration.
  4. The method of any of claims 1-3, wherein the solid comprises at least one compound selected from (trans-2-perfluoropropoxy-1,2-difluoroethen-1-yl) (tributyl) phosphonium tetrafluoroboranuide, (cis-2-perfluoropropoxy-1,2-difluoroethen-1-yl) (tributyl) phosphonium tetrafluoroboranuide, perfluoropropoxy vinyl ether, (2,2,3,3,3-pentafluoro-1-tributylphosphin-1-one) tetrafluoroboranuide, boron trifluoride tributylphosphine oxide, tetrafluoroboric acid, (1,2-difluoroethen-1-yl) (tributyl) phosphonium tetrafluoroboranuide), diethyl ether, dimethyl ether, and 2-methoxy-2-methylpropane.
  5. The method of any of claims 1-4, wherein the purity of the phosphorus-containing olefin compound salt in the purified product is ≥ 95 mass%.
  6. A method for producing an olefin compound, comprising (i) purifying a phosphorus-containing olefin compound salt by performing the method of any of claims 1-5, and (ii) reacting the obtained purified product and a base to thereby obtain a reaction product containing a dephosphorized and hydrogenated olefin compound.
  7. The method of claim 6, wherein the olefin compound is (E)-1,2-difluoroethylene.
  8. The method of claim 6 or 7, wherein the reaction product comprises (E)-1,2-difluoroethylene and at least one of acetylene, trifluoroethylene, pentafluoroethane (R-125), 1,1,1,2-tetrafluoroethane (R-134a), (Z)-1,2-difluoroethylene, tetrafluoroethylene, and cis- and trans-1H-nonafluoro-2-propoxyethene.

Description

Technical Field The present invention relates to a method for purifying a phosphorus-containing olefin compound salt and a method for producing an olefin compound using a purified product obtained thereby. Background Art (E)-1,2-difluoroethylene (hereinafter referred to as "R1132(E)") has a low global warming potential (GWP), and thus has attracted attention as an alternative refrigerant to difluoromethane (R-32) and 1,1,1,2,2-pentafluoroethane (R-125), which are greenhouse gases. Conventionally, as a method for producing R1132(E), for example, H.-J. Frohn et al, J. Fluorine Chem., 123, 43-49 (2003) has reported that a reaction product containing a target product can be obtained according to the following procedure (Abstract and "3.2. Reactions of olefin 1 with Pbu3," in particular, 3.2.2) . The above report example states that in addition to the target product R1132(E), about 16% (0.3 g for 1.9 g) of cis- and trans-1H-nonafluoro-2-propoxyethene (cis:trans = 1:5) was also present as an impurity. R. Blachnik et al., Zeitschrift für Kristallographie - New Crystal Structures, 216(1-4), 219-220 (2001) report on the crystal structure of [Ph3P-CH=CH-PPh3][BF4]2, using single crystals obtained by reacting starting materials in dry ethanolic solution to produce the target compound, filtrating the reaction solution and slowly evaporating the solvent, so that single crystals of the target compound precipitated from the solution. H. Wessolowski et al., J. Fluorine Chem., 80(2), 149-152 (1996) describes the synthesis of perfluoroalkenyl phosphonates and iodoperfluoroalkenes from CF3-C(CF3)2-CF=CF2 and (n-F9C4)O-CF=CF2. Summary of Invention Technical Problem The present invention was made in view of the above problems, and an object of the present invention is to provide a method for purifying a phosphorus-containing olefin compound salt as a raw material or an intermediate that is useful to increase the purity of a target product in a method for producing an olefin compound and that can be applied to the production method, and to also provide a method for producing an olefin compound using a purified product obtained thereby. Solution to Problem The present invention thus provides a method for purifying a phosphorus-containing olefin compound salt (also referred to as "the present purification method" hereinafter), comprising reprecipitating and/or recrystallizing a solid comprising at least one phosphorus-containing olefin compound salt of formula (1) or (2): wherein X1, X2 each independently are H,F, Cl, Br or I;Y is H, F, Cl, Br, I, alkyl, alkyl ether, fluoroalkyl or fluoroalkyl ether;W+ each independently is a monovalent cation comprising PR3 or P(OR)3, wherein R each independently are groups having a saturated or unsaturated structure containing C and H, are optionally bonded together to form a ring, and optionally contain an atom other than C and H; andM- is a boron fluoride anion;in a solvent, thereby obtaining a purified product of the phosphorus-containing olefin compound salt,wherein after the solid is dissolved in a solvent at 45-60°C, the temperature of a solution is reduced at -0.25°C/min or less to thereby perform reprecipitation and/or recrystallization. Also, the present invention provides a method for producing an olefin compound (also referred to as "the present production method" hereinafter), comprising (i) purifying a phosphorus-containing olefin compound salt by performing the method defined above, and(ii) reacting the obtained purified product and a base to thereby obtain a reaction product containing a dephosphorized and hydrogenated olefin compound. Preferred embodiments of the invention are as defined in the appended dependent claims and/or in the following detailed description. Advantageous Effects of Invention According to the present purification method, a solid containing the salt is reprecipitated and/or recrystallized in a solvent, thereby obtaining a highly purified product of the phosphorus-containing olefin compound salt. The purified product of the phosphorus-containing olefin compound salt is useful as a raw material or an intermediate in a method for producing an olefin compound. An olefin compound with high purity can be produced by synthesizing the target product using the purified product as a raw material or an intermediate. Description of Embodiments The present purification method comprises reprecipitating and/or recrystallizing a solid comprising at least one phosphorus-containing olefin compound salt of formula (1) or (2): wherein X1, X2 each independently are H,F, Cl, Br or I;Y is H, F, Cl, Br, I, alkyl, alkyl ether, fluoroalkyl or fluoroalkyl ether;W+ each independently is a monovalent cation comprising PR3 or P(OR)3, wherein R each independently are groups having a saturated or unsaturated structure containing C and H, are optionally bonded together to form a ring, and optionally contain an atom other than C and H; andM- is a boron fluoride anion;in a solvent, thereby