JPS61225150A - 3,3,3-trifluoro-2-trifluoromethyl-2-substituted propionyl fluoride - Google Patents

Abstract

PURPOSE:Heptafluoroisobutenyl ether is subjected to isomerization reaction using a specific quaternary or tertiary salt as an isomerization reaction catalyst to give the title compound which is used as a synthetic intermediate of surface active agent, medicines and so on. CONSTITUTION:A heptafluoro-i-butenyl ether of the formula: (CF3)2=CFOR (R is hydrocarbon) is subjected to isomerization reaction under normal pressure, using, as an isomerization catalyst, a quaternary ammonium salt such as benzyl triethylammonium chloride, quaternary phosphonium salt, e.g., benzyltriphenylphosphonium chloride, or tertiary sulfonium salt such as dodecyl ethyl methyl slufonium chloride, preferably in an amount of about 0.1-10wt% based on the heptafluoro-i-butenyl ether to give the titled compound. USE:Intermediate of agricultural chemicals and starting material for manufacturing monomers for functional polymers.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing 3,3,3-trifluoro-2-trifluoromethyl-2-substituted propionic acid florade. More specifically, the present invention relates to a method for producing 3.3.3-trifluoro-2-trifluoromethyl-2-substituted propionic acid florade from heptafluoroisobutenyl ether.

[Conventional technology]

Octafluoroisobutyne is a by-product during the production of hexafluoropropene, which is an important raw material for fluorine-containing copolymers.This highly toxic octafluoroisobutyne is generally used in lower alcohols, such as methanol and ethanol. , n-propanol, isopropanol, n-butanol, and the like.

This alcohol adduct, octafluoroisobutyl alkyl ether, is stirred with an alkali metal or alkaline earth metal hydroxide or carbonate or a base such as a trialkylamine in the presence of a phase transfer catalyst such as a quaternary ammonium salt. The dehydrofluorination reaction is carried out to give heptafluoroisobutenyl alkyl ether.

The heptafluoroisobutenyl alkyl ether thus obtained isomerized when reacted with a catalytic amount of tertiary amine to form 3,3,3-trifluoro-2-1-lifluoromethyl-2-alkylpropion. Give acid florade (Izv, Akad, Nauk, 5S
S.R.

Ser, Khim 1967 Vol.
, requiring strict conditions such as 24 to 30 hours.

[Problem that the invention seeks to solve]

As a result of various studies in search of a method for performing the isomerization reaction of heptafluoroisobutenyl alkyl ether under milder conditions, the present inventor found that a specific quaternary salt or tertiary salt as an isomerization reaction catalyst was found. We have found that the reaction can be carried out even under atmospheric pressure by using . Further, this isomerization reaction is equally applicable not only to alkyl ethers but also to aryl ethers and the like.

[Means for Solving the Problems] and [Operation] Therefore, the present invention relates to a method for producing 3,3,3-trifluoro-2-1-lifluoromethyl-2-substituted propionic acid florade, which has the general formula (CF3)2CRCOF (where R
is a hydrocarbon group] The production of fluorade 3,3-1-refluoro-2-trifluoromethyl-2=substituted propionic acid is carried out using the general formula (CF3)2C=CF
Isomerizing heptafluoroisobutenyl ether represented by OR [where R is a hydrocarbon group] in the presence of a quaternary ammonium salt, a quaternary phosphonium salt, or a tertiary sulfonium salt. This is done by

As the raw material heptafluoroisobutenyl ether, as mentioned above, alkyl ethers such as methyl, ethyl, n-propyl, isobutyl, n-butyl, aryl ethers such as phenyl, or aralkyl ethers such as benzyl are used.

Examples of quaternary ammonium salts used as isomerization reaction catalysts include penzyltriethylammonium chloride, cetylbenzyldimethylammonium chloride, and phenyltriethylammonium chloride; examples of quaternary phosphonium salts include benzyltriphenylphosphonium chloride, n. Examples of the tertiary sulfonium salt include -butyltriphenylphosphonium chloride and cetyltri(n-butyl)phosphonium bromide. Examples of the tertiary sulfonium salt include dodecylethylmethylsulfonium chloride and dimxylmethylsulfonium iodide.

The reaction is carried out using these isomerization reaction catalysts in an amount of about 0.1 to 10% by weight based on heptafluoroisobutenyl ether.
-, carried out by heating under reflux conditions.

Among the isomerization reaction catalysts listed in 2 above, quaternary ammonium salts are also used as catalysts for the dehydrogenation reaction of octafluoroin butyl alkyl ether, as mentioned above.
For example, when tetramethylammonium chloride is used, hebutafluoroisobutenyl alkyl ether is given, but when ben=4-diltriethylammonium chloride is used, the dehydrofluorination reaction may occur depending on the temperature conditions. In addition, the isomerization reaction proceeds to produce 3.3.3-1-refluoro-2-trifluoromethyl-2-substituted propionic acid fluorade.

〔Effect of the invention〕

According to the method of the present invention, 3,3,3-trifluoro-3,3,3-trifluoro-
2-trifluoromethyl-2-substituted propionic acid fluorade can be obtained almost quantitatively even if heptafluoroisobutenyl ether is subjected to an isomerization reaction under mild conditions of about several hours under atmospheric pressure. Furthermore, since the product has a low boiling point, continuous reaction is possible in an atmospheric pressure system.

〔Example〕

Next, the present invention will be explained with reference to examples.

Example].

In a 20 m Q flask equipped with a Dimroth condenser, thermometer, and stirrer, 10.0 g (47 mmol) heptafluoroisobutenyl methyl ether and 0.1 g benzyl 1-ethylammonium chlorite.
was charged and refluxed for 6 hours. After the reaction is complete, heat the
, 3.3-1~lifluoro-2-1~lifluoromethyl-2-methylpropionic acid fluorade (boiling point 47~49
9.2 g (yield: 92.0%) of the product (yield: 92.0%) was obtained.

Example 2 In Example 1, when 10.0 g (44 mmol) of heptafluoroisobutenyl ethyl ether was used instead of heptafluoroin butenyl methyl ether, 3,3.3-trifluoro-2 8.7 g (yield: 87%) of -trifluoromethyl-2-ethylpropionic acid fluorade (boiling point 74-76°C) was obtained.

Example 3 In Example 1, when 0.1 g of benzyltriphenylphosphonium chloride was used instead of benzyltriethylammonium chloride, 3,3°3-trifluoro-2-1-lifluoromethyl-2-methylpropionic acid 9.0 g (yield 90%) of Florade was obtained.

Example 4 In Example 1, if 0.1 g of dodecylethylmethylsulfonium chloride was used instead of benzyltriethylammonium chloride, 3,3°3-1-lifluoro-2-trifluoromethyl-2-methylpropionic acid fluorade 8.6 g (yield 86%) was obtained.

Claims (1)

[Claims] 1. General formula (CF_3)_2C=CFOR [where R
is a hydrocarbon group] is subjected to an isomerization reaction in the presence of a quaternary ammonium salt, a quaternary phosphonium salt, or a tertiary sulfonium salt. Formula (CF_3)_2
A method for producing 3,3,3-trifluoro-2-trifluoromethyl-2-substituted propionic acid florade represented by CRCOF [here, R is a hydrocarbon group]. 2. A method for producing 3,3,3-trifluoro-2-trifluoromethyl-2-substituted propionic acid florade according to claim 1, wherein the reaction is carried out under atmospheric pressure.