CN107840796B

CN107840796B - Preparation method of trifluoromethyl alkenyl ester

Info

Publication number: CN107840796B
Application number: CN201711106760.0A
Authority: CN
Inventors: 赵波; 张伟; 曾纪珺; 韩升; 唐晓博; 马辉; 郝志军; 毛伟; 王博; 李凤仙; 吕剑
Original assignee: Xian Modern Chemistry Research Institute
Current assignee: Xian Modern Chemistry Research Institute
Priority date: 2017-11-10
Filing date: 2017-11-10
Publication date: 2020-12-15
Anticipated expiration: 2037-11-10
Also published as: CN107840796A

Abstract

The invention discloses a preparation method of trifluoromethyl alkene ester, which comprises the following steps of in the presence of a catalyst, preparing fluorine-containing alkyne CF₃CH≡CR₁And R₂COOH reaction to obtain trifluoromethyl alkene ester, wherein the catalyst is tertiary amine, potassium phosphate or alkali metal hydroxide. The invention provides a green and efficient synthetic method capable of being applied in a large scale, which is mainly used for preparing trifluoromethyl alkenyl ester.

Description

Preparation method of trifluoromethyl alkenyl ester

Technical Field

The invention belongs to the field of fluorine-containing materials, and relates to a preparation method of trifluoromethyl alkenyl ester.

Background

In the past decades, research on the synthesis of fluorine-containing compounds has been a hot area of interest to chemists. Fluorine atom as the element with the strongest electron withdrawing ability can form a C-F bond with strong bond energy with carbon atom, and the atomic radius of the fluorine atom is similar to that of hydrogen atom, so that the physicochemical property and the biological activity of the compound can be obviously changed after the atom is introduced into an organic matter.

Fluorine-containing organic substances are widely applied to the fields of chemical drugs, pesticides, photoelectric materials and the like, and most of the existing organic fluorine-containing substances do not exist in the nature and need to be artificially synthesized. Therefore, research on the synthesis of fluorine-containing organic substances has enabled a large variety of fluorine-containing substances and means.

Fluorine-containing polymers are one of important applications of fluorine-containing olefin compounds, and because fluorine atoms have unique properties such as thermal stability, hydrophobicity and the like, the fluorine-containing polymer materials obtained by polymerizing fluorine-containing olefins play an important role in the field of special materials, such as: the hydrophobic material Teflon (polytetrafluoroethylene) obtained by polymerizing the tetrafluoroethylene monomer is widely applied in the industrial field, the fluorine-containing alkenyl ester compound is also a fluorine-containing polymer monomer, and the synthetic method is simple and cheap, so the hydrophobic material Teflon (polytetrafluoroethylene) has a higher industrial application prospect.

The traditional synthetic method of the alkene ester compound is obtained by catalyzing addition reaction of alkyne acids by noble metals, such as: a comparison document (ACS cat.2015, 5,6918-6921) reports that gold is used for catalyzing acid addition reaction of alkyne, and a gold catalyst which is expensive and difficult to prepare is used, so that large-scale application is difficult.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a preparation method of trifluoromethyl alkene ester, which is green and efficient, can be applied in a large scale, and has the advantages of convenient post-treatment and low production cost.

The invention relates to a preparation method of trifluoromethyl alkene ester, wherein the general formula of the trifluoromethyl alkene ester is shown as the formula (I):

the method comprises the following steps:

with CF₃CH≡CR₁And R₂COOH is used as a raw material, and is synthesized to obtain trifluoromethyl alkene ester in the presence of a catalyst, wherein the reaction equation is as follows:

CF as a raw material₃CH≡CR₁And R₂COOH, in the presence of a catalyst, a fluorine-containing alkyne CF₃CH≡CR₁And R₂COOH to obtain trifluoromethyl alkene ester (I), wherein R in the raw material and the product₁Is hydrogen, perfluoroalkyl, alkyl or aryl, R₂Hydrogen, alkyl or aryl, the catalyst is tertiary amine, metal phosphate or hydroxide, and the reaction conditions are as follows: CF (compact flash)₃CH≡CR₁And R₂COOH is used as a raw material, the molar ratio of the COOH to the R is 1-5: 1₂The molar ratio of COOH is 0.01-2.01: 1, the reaction temperature is 0-180 ℃, and the reaction time is 1-48 h.

The fluorine-containing alkyne CF₃CH≡CR₁Is 1,1,1,4,4, 4-hexafluoro-2-butyne, trifluoropropyne, 4-trifluoromethylphenylacetylene or 2-ethynyltrifluorotoluene.

The R is₂COOH is p-methoxybenzoic acid, n-octanoic acid, p-toluenesulfonic acid, p-methoxysulfinic acid.

The catalyst is triethylamine, diisopropylethylamine, potassium phosphate or cesium hydroxide.

The preferred reaction conditions are: CF (compact flash)₃CH≡CR₁And R₂The molar ratio of COOH is 1-3: 1, and the catalyst and R are₂The molar ratio of COOH is 0.05-1.1: 1, the reaction temperature is 25-120 ℃, and the reaction time is 2-16 h.

The invention has the advantages that:

(1) the comparison document adopts an expensive gold catalyst, and the method can be carried out without metal, so that the method is more green and efficient.

(2) The invention uses cheap alkali catalyst, which is convenient for post-treatment and can be applied in large scale. (3) The fluorine-containing alkyne serving as the raw material is a fluorine chemical product and is cheap and easy to obtain.

Detailed Description

The present invention is further illustrated by the following specific examples, which are not intended to limit the invention in any way.

Example 1:

2mL of dichloromethane, 0.025g of triethylamine and 0.152g of p-methoxybenzoic acid are added into a 25mL Schlenk tube, after cooling by liquid nitrogen, the mixture is vacuumized, 0.2-0.3g of 1,1,1,4,4, 4-hexafluoro-2-butyne is sucked in, the mixture reacts at 25 ℃ for 10 hours, and the target product is obtained after reduced pressure distillation, wherein the yield is 99%.

Examples 2 to 4:

examples 2 to 4 trifluoromethyleneesters were prepared by the same preparation method as in example 1, except that the trifluoromethylalkyne in example 1 was 1,1,1,4,4, 4-hexafluoro-2-butyne, and examples 2 to 4 were trifluoropropyne, 4-trifluoromethylphenylacetylene or 2-ethynyltrifluorotoluene, respectively. The reaction results of examples 2 to 4 are shown in Table 1.

TABLE 1 reaction results for trifluoromethyl alkynes

Examples	Alkynes of acetylene	Catalyst and process for preparing same	Yield (%)
				2	Trifluoropropyne	Triethylamine	95
3	4-trifluoromethylphenylacetylene	Diisopropylethylamine	91
				4	2-ethynyl trifluorotoluene	Diisopropylethylamine	76

Examples 5 to 7:

examples 5 to 7 trifluoromethyleneesters were prepared by the same preparation method as in example 1, except that the trifluoromethylalkyne in example 1 was 1,1,1,4,4, 4-hexafluoro-2-butyne, and the starting materials 2-bromotrifluoropropene, 2-chlorotrifluoropropene or 1-chlorotrifluoropropene were used in examples 5 to 7. The reaction results of examples 5 to 7 are shown in Table 2.

TABLE 2 reaction results for different kinds of olefins

Examples	Olefins	Catalyst and process for preparing same	Yield (%)
				5	2-bromotrifluoropropene	Triethylamine	83
6	2-chlorotrifluoropropene	Triethylamine	71
				7	1-chlorotrifluoropropene	Cesium hydroxide	65

Examples 8 to 10:

examples 8 to 10 Trifluoromethylene ester was prepared by the same preparation method as in example 1, except that the reactant in example 1 was p-methoxybenzoic acid, and the reactant in examples 8 to 10 was n-octanoic acid, p-toluenesulfonic acid or p-methoxysulfinic acid. The reaction results of examples 8 to 10 are shown in Table 3.

TABLE 3 influence of catalyst amounts

Examples	Reactants	Catalyst and process for preparing same	Yield (%)
				8	N-octanoic acid	Cesium hydroxide	71
9	P-toluenesulfonic acid	Triethylamine	89
				10	P-methoxysulfinic acid	Diisopropylethylamine	81

Examples 11 to 13:

examples 11 to 13 Trifluoromethylene esters were prepared by the same preparation method as in example 1, except that triethylamine was used as a catalyst in example 1, and diisopropylethylamine, potassium phosphate or cesium hydroxide was used as a catalyst in examples 11 to 13, respectively. The reaction results of examples 11 to 13 are shown in Table 4.

TABLE 4 Effect of reaction time on the reaction

Examples	Catalyst and process for preparing same	Yield (%)
			11	Diisopropylethylamine	99
12	Potassium phosphate	65
			13	Cesium hydroxide	71

Claims

1. A method for preparing trifluoromethyl alkene ester, wherein the general formula of the trifluoromethyl alkene ester is shown as the formula (I):

the method comprises the following steps: fluorine-containing alkyne CF in the presence of a catalyst₃CH≡CR₁And R₂COOH reaction to give trifluoromethylene esters (I), wherein the fluorine-containing alkynes CF₃CH≡CR₁Is 1,1,1,4,4, 4-hexafluoro-2-butyne, trifluoropropyne, and the R is₂COOH is p-methoxybenzoic acid, a catalyst is tertiary amine, and the reaction conditions are as follows: CF (compact flash)₃CH≡CR₁And R₂COOH is used as a raw material, the molar ratio of the COOH to the R is 1-5: 1₂The molar ratio of COOH is 0.01-2.01: 1, the reaction temperature is 0-180 ℃, and the reaction time is 1-48 h.

2. The process for preparing trifluoromethylene esters according to claim 1, wherein the catalyst is triethylamine or diisopropylethylamine.

3. The process for the preparation of trifluoromethylene esters as claimed in claim 1, wherein the reaction conditions are as follows: CF (compact flash)₃CH≡CR₁And R₂The molar ratio of COOH is 1-3: 1, and the catalyst and R are₂The molar ratio of COOH is 0.05-0.2: 1, the reaction temperature is 25-60 ℃, and the reaction is carried outThe time is 2-16 h.