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CN-115003652-B - Method for purifying carboxylic acid fluoride

CN115003652BCN 115003652 BCN115003652 BCN 115003652BCN-115003652-B

Abstract

The yield of R-COF is prevented from decreasing due to the mixing of impurities, and a high-purity R-COF product is stably produced. According to the present invention, there are provided a method for purifying a carboxylic acid fluoride comprising a step of bringing a carboxylic acid fluoride containing a hydrogen halide into contact with a metal fluoride to remove the hydrogen halide, a method for producing a high-purity carboxylic acid fluoride comprising a step of bringing a carboxylic acid fluoride containing a hydrogen halide into contact with a metal fluoride, a high-purity carboxylic acid fluoride obtained by the method, and a method for using a metal fluoride as a hydrogen halide adsorbent in a method for removing a hydrogen halide from a carboxylic acid fluoride containing a hydrogen halide.

Inventors

  • Mu Cunliang
  • NAKANISHI AKIKO
  • MAEHARA KOHEI

Assignees

  • 关东电化工业株式会社

Dates

Publication Date
20260512
Application Date
20210122
Priority Date
20200122

Claims (9)

  1. 1. A process for purifying a carboxylic acid fluoride, comprising the steps of bringing a carboxylic acid fluoride containing a hydrogen halide into contact with a metal fluoride to remove the hydrogen halide and obtain a carboxylic acid fluoride having a purity of 99.999% or higher, wherein the step of removing the hydrogen halide and obtaining a carboxylic acid fluoride having a purity of 99.999% or higher comprises passing the carboxylic acid fluoride containing a hydrogen halide through a metal fluoride packed column, further comprises subjecting the carboxylic acid fluoride having passed through the metal fluoride packed column to distillation purification in a distillation column, The metal fluoride is sodium fluoride and the metal fluoride is sodium fluoride, The carboxylic acid fluoride is at least one selected from the group consisting of difluoroacetyl fluoride (CHF 2 COF), trifluoroacetyl fluoride, perfluoro-n-butyryl fluoride, and perfluoro-n-heptanoyl fluoride.
  2. 2. A process for producing a carboxylic acid fluoride having a purity of 99.999% or more, which comprises a step of bringing a carboxylic acid fluoride containing hydrogen halide into contact with a metal fluoride to remove the hydrogen halide, wherein the step of removing the hydrogen halide comprises passing the carboxylic acid fluoride containing hydrogen halide through a metal fluoride packed column, and further comprises subjecting the carboxylic acid fluoride having passed through the metal fluoride packed column to distillation purification in a distillation column, The metal fluoride is sodium fluoride and the metal fluoride is sodium fluoride, The carboxylic acid fluoride is at least one selected from the group consisting of difluoroacetyl fluoride (CHF 2 COF), trifluoroacetyl fluoride, perfluoro-n-butyryl fluoride, and perfluoro-n-heptanoyl fluoride.
  3. 3. A method of using a metal fluoride as a hydrogen halide adsorbent in a method of removing hydrogen halide from a hydrogen halide-containing carboxylic acid fluoride to obtain a carboxylic acid fluoride having a purity of 99.999% or more, the method of removing hydrogen halide to obtain a carboxylic acid fluoride having a purity of 99.999% or more comprising passing the hydrogen halide-containing carboxylic acid fluoride through a metal fluoride packed column, further comprising subjecting the carboxylic acid fluoride passed through the metal fluoride packed column to distillation refining in a distillation column, The metal fluoride is sodium fluoride and the metal fluoride is sodium fluoride, The carboxylic acid fluoride is at least one selected from the group consisting of difluoroacetyl fluoride (CHF 2 COF), trifluoroacetyl fluoride, perfluoro-n-butyryl fluoride, and perfluoro-n-heptanoyl fluoride.
  4. 4. The method according to any one of claim 1 to 3, wherein, The hydrogen halide-containing carboxylic acid fluoride is the reaction product of the halogen exchange reaction described below, R-COX 1 +HF→R-COF+HX 1 Wherein R is a 1-valent organic group, a hydrogen atom or a halogen atom, and X 1 is a halogen atom other than fluorine.
  5. 5. The method according to any one of claims 1 to 3, wherein the hydrogen halide-containing carboxylic acid fluoride is a reaction product of a reaction of carboxylic acid chloride and a metal fluoride.
  6. 6. The method according to any one of claims 1 to 3, wherein the hydrogen halide-containing carboxylic acid fluoride is a reaction product of a reaction of carboxylic acid chloride with chromium fluoride.
  7. 7. The method according to any one of claims 1 to 3, wherein the hydrogen halide is at least 1 selected from the group consisting of hydrogen fluoride and hydrogen chloride.
  8. 8. A method according to any one of claims 1 to 3, wherein the carboxylic acid fluoride is trifluoroacetyl fluoride.
  9. 9. The method of any of claims 1-3, wherein the packed column temperature is 15-35 ℃.

Description

Method for purifying carboxylic acid fluoride Technical Field The present invention relates to a process for purifying carboxylic acid fluorides (R-COFs), wherein R is a 1-valent organic group, a hydrogen atom, a halogen atom. The invention also relates to a high purity R-COF and a method for producing the same. Background It is known that R-COF compounds (in particular COF 2) are difficult to separate from hydrogen halide (in particular HF) by distillation and require a considerable amount of time and expense for purification. Patent document 1 discloses that a gas mixture containing HF, HCl and/or HBr and other components, in particular, a gas mixture containing carboxylic acid fluoride, COF 2 or phosphorus pentafluoride and HCl and, if necessary, HF can be fractionated using an ionic liquid. However, the purification method of patent document 1 requires an expensive ionic liquid, and has a problem that HCl remains in the purified product in a percentage order even if the ionic liquid is introduced. Patent document 2 discloses a method for separating an acid from a system in which an organic acid fluoride and an acid are mixed, wherein an aromatic heterocyclic compound having a boiling point of 50 ℃ or higher and a nitrogen atom as a heteroatom is used as a deoxidizer. However, this method has a problem that an aromatic heterocyclic compound is mixed with the flow of gas, which prevents the ultra-high purity. On the other hand, for a complex of R-COF and hydrogen halide, there is a report on the finding that this complex exists in this particular case. Non-patent document 1 discloses a complex of CH 3 COF and HI. However, there have been few reports on such complexes, and it has not been known to be sufficient. Prior art literature Patent literature Patent document 1 Japanese patent 5473222 (Japanese patent application No. 2007-538309) Patent document 2 Japanese patent 4264689 (Japanese patent application No. 2001-396680) Non-patent literature Non-patent document 1 J.Phys.chem.A, vol.101, no.49,1997, p.9260-9271 Disclosure of Invention Problems to be solved by the invention As a result of intensive studies by the present inventors, it was confirmed that R-COF forms a complex with hydrogen Halide (HX). Such complexes are represented, for example, by the formula R-COF-HX (x= F, cl, br, I). R-COF is difficult to separate from the complex, and therefore, the following halogen exchange reaction is performed: R-COX1+HF→R-COF+HX1 (wherein R is a 1-valent organic group, a hydrogen atom, or a halogen atom, and X 1 is a halogen atom other than fluorine), and the R-COF-HX complex is contained in the reaction product, and thus, even if the synthesis yield (crude yield) before purification is high, the removal of the initial fraction to remove impurities or the like causes a reduction in the R-COF yield (distillation yield) due to distillation (reduction in the distillation yield). In addition, when the purpose is to produce an ultra-high purity R-COF having a purity of 5N (99.999% or more and less than 99.9999%) or more, such an ultra-high purity product cannot be produced by conventional purification methods (ultra-high purification is prevented). Accordingly, an object of the present invention is to stably produce a high-purity R-COF product by preventing a decrease in the yield of R-COF due to contamination with impurities. Solution for solving the problem As a result of intensive studies, the present inventors have found that by using a metal fluoride as a hydrogen halide adsorbent, an R-COF-HX complex can be decomposed effectively, and thus, an improvement in the yield and an ultra-high purity of the R-COF compound can be achieved. Namely, the present invention provides the following. [1] A process for purifying a carboxylic acid fluoride, which comprises a step of bringing a carboxylic acid fluoride containing a hydrogen halide into contact with a metal fluoride to remove the hydrogen halide. [2] A process for producing a high-purity carboxylic acid fluoride, which comprises the step of bringing a carboxylic acid fluoride containing a hydrogen halide into contact with a metal fluoride. [3] A method of using a metal fluoride as a hydrogen halide adsorbent in a process for removing hydrogen halide from a hydrogen halide-containing carboxylic acid fluoride. [4] The method according to any one of [1] to [3], wherein the hydrogen halide-containing carboxylic acid fluoride is a reaction product of a halogen exchange reaction, R-COX1+HF→R-COF+HX1 (Wherein R is a 1-valent organic group, a hydrogen atom or a halogen atom, and X 1 is a halogen atom other than fluorine). [5] The method according to any one of [1] to [3], wherein the hydrogen halide-containing carboxylic acid fluoride is a reaction product in a reaction of carboxylic acid chloride and a metal fluoride. [6] The method according to any one of [1] to [3], wherein the hydrogen halide-containing carboxylic acid fluoride is a reaction product in a reaction of ca