A kind of synthetic method of 2-bromo-2,3,3,3-tetrafluoropropionic acid ethyl ester

Abstract

The present application relates to the technical field of fluorine-containing intermediate synthesis, and specifically discloses a synthetic method of 2-bromo-2,3,3,3-tetrafluoroethyl propionate. A synthetic method of 2-bromo-2,3,3,3-tetrafluoroethyl propionate, comprising the following steps: addition reaction: using hexafluoropropylene and ethanol to carry out addition reaction under the action of a base catalyst to obtain 1,1,2,3,3,3-pentafluoropropyl ether; hydrolysis reaction: 1,1,2,3,3,3-pentafluoropropyl ether is hydrolyzed under the action of an acid catalyst to obtain 2,3,3,3-tetrafluoroethyl propionate; bromination reaction: 2,3,3,3-tetrafluoroethyl propionate and a bromination agent are subjected to bromination reaction to obtain 2-bromo-2,3,3,3-tetrafluoroethyl propionate. The synthetic method in this application, not only has high yield, and the raw material source is simple and corrosion-free, the reaction is simple and easy to operate, the process is simple and suitable for industrial production, low cost, and high economic benefit.

Description

Technical Field

[0001] The present application relates to the technical field of synthesis of fluorine-containing intermediates, and in particular to a method for synthesizing ethyl 2-bromo-2,3,3,3-tetrafluoropropionate. Background Art

[0002] Ethyl 2-bromo-2,3,3,3-tetrafluoropropionate is an important organic synthesis reagent, which is often used to introduce a tetrafluoropropionyl unit into the target organic molecular structure. It has high reactivity and selectivity, so it is widely used in organic synthesis, catalysis and material science. Especially in the research and development and preparation of fluorine-containing drugs, 2-bromo-2,3,3,3-tetrafluoropropionate plays an important role in sedation, antimicrobial, anesthesia and other fields because of its strong physiological activity and long action time.

[0003] In addition, ethyl 2-bromo-2,3,3,3-tetrafluoropropionate is also commonly found in laboratories as a chemical reagent for research and teaching purposes. It can derive more related compounds through the reactivity of ester bond functional groups, and is further used to synthesize fluorine-containing compounds such as medicines, pesticide intermediates, and dyes. These compounds are also widely used in materials science and catalytic reactions.

[0004] Furthermore, 2-bromo-2,3,3,3-tetrafluoropropionic acid ethyl ester is a high value-added fluorine-containing pharmaceutical and pesticide intermediate, with a molecular formula of C5H5BrF4O2, a molecular weight of 252.99, and a boiling point of 122°C. There are few literatures on the synthesis of this product, and since the molecular structure of this product contains both fluorine atoms and bromine atoms, the synthesis of this product is relatively difficult.

[0005] There are two main ways to synthesize ethyl 2-bromo-2,3,3,3-tetrafluoropropionate: one method is to synthesize ethyl 2-bromo-2,3,3,3-tetrafluoropropionate from ethanol and 2-bromo-2,3,3,3-tetrafluoropropionyl fluoride. The specific steps include using ethanol and 2-bromo-2,3,3,3-tetrafluoropropionyl fluoride to react to generate the target product; the other method is to use 2,3,3,3-tetrafluoropropionic acid as a starting material, use a brominating agent to replace the hydrogen on the 2-carbon atom to obtain 2-bromo-2,3,3,3-tetrafluoropropionic acid, and then use concentrated sulfuric acid to catalyze the reaction with ethanol to obtain ethyl 2-bromo-2,3,3,3-tetrafluoropropionate. In the above-mentioned synthetic routes, there are the disadvantages of difficulty in sourcing reaction raw materials, difficulty in synthesizing raw materials resulting in small production capacity and low yield, making it difficult to carry out large-scale production, strong acidic raw materials being highly corrosive and requiring extremely high equipment, and complex processes, making it difficult to obtain satisfactory results in industrial preparation. Summary of the invention

[0006] In order to improve the yield of ethyl 2-bromo-2,3,3,3-tetrafluoropropionate and solve the problem of difficult raw material sources and strong corrosiveness, the present application provides a method for synthesizing ethyl 2-bromo-2,3,3,3-tetrafluoropropionate.

[0007] The present application provides a method for synthesizing ethyl 2-bromo-2,3,3,3-tetrafluoropropionate, which adopts the following technical scheme: A method for synthesizing ethyl 2-bromo-2,3,3,3-tetrafluoropropionate comprises the following steps: Addition reaction: Hexafluoropropylene and ethanol are subjected to an addition reaction in the presence of a base catalyst to obtain 1,1,2,3,3,3-pentafluoropropyl ether; Hydrolysis reaction: 1,1,2,3,3,3-pentafluoropropyl ethyl ether is hydrolyzed under the action of an acid catalyst to obtain 2,3,3,3-tetrafluoropropionic acid ethyl ester; Bromination reaction: 2,3,3,3-tetrafluoropropionic acid ethyl ester and a brominating agent are subjected to bromination reaction to obtain 2-bromo-2,3,3,3-tetrafluoropropionic acid ethyl ester.

[0008] By adopting the above technical scheme, the industrial fluorine-containing monomer hexafluoropropylene is used as the starting raw material to effectively solve the disadvantages of difficulty in raw material source and corrosiveness of the raw material, avoid the harsh conditions of fluorine substitution reaction, and have low requirements on reaction equipment. Simple addition reaction under base catalysis and hydrolysis reaction under acid catalysis are carried out, and the use of a large amount of strong base and strong acid is avoided. The reaction is simple and easy to operate, and the process is simple and suitable for industrial production. Finally, the target product is prepared by bromination under mild conditions, with high total yield, low cost, high economic benefit, and simple raw material source and no corrosion.

[0009] In a specific embodiment, the synthesis formula of ethyl 2-bromo-2,3,3,3-tetrafluoropropionate is:

[0010] In a specific embodiment, the base catalyst includes one of potassium hydroxide and sodium hydroxide.

[0011] In a specific embodiment, the acid catalyst includes one of concentrated sulfuric acid and polyphosphoric acid.

[0012] In a specific embodiment, the bromination reagent includes one of bromine and N-bromosuccinimide.

[0013] In a specific embodiment, the addition reaction steps are: first add the base catalyst to ethanol, stir, add hexafluoropropylene at 0°C, heat to 20-55°C, keep stirring for 2-10 hours, and then distill at atmospheric pressure to obtain 1,1,2,3,3,3-pentafluoropropyl ether.

[0014] By adopting the technical solution, the temperature and time of the addition reaction are further limited, thereby improving the yield and purity of 1,1,2,3,3,3-pentafluoropropyl ethyl ether.

[0015] In a specific embodiment, the hydrolysis reaction step is: adding 1,1,2,3,3,3-pentafluoropropyl ethyl ether to water, adding an acid catalyst at 0°C, heating to 20-50°C, keeping warm and stirring for 1-5 hours, and after the reaction is completed, the lower layer is separated, washed with water and dried to obtain 2,3,3,3-tetrafluoropropionic acid ethyl ester.

[0016] By adopting the technical scheme, the temperature and time of the hydrolysis reaction are further limited, thereby improving the yield and purity of 2,3,3,3-tetrafluoroethyl propionate.

[0017] In a specific embodiment, the bromination reaction step is: add ethyl 2,3,3,3-tetrafluoropropionate to a glass kettle, add a bromination reagent at 0°C, heat to 50-80°C, keep warm and stir for 1-5 hours, and after the reaction is completed, recover ethyl 2,3,3,3-tetrafluoropropionate by atmospheric distillation, and wash the bottom liquid with water to obtain ethyl 2-bromo-2,3,3,3-tetrafluoropropionate.

[0018] By adopting the above technical scheme, the temperature and time of the bromination reaction are further limited, thereby improving the yield and purity of the final product 2-bromo-2,3,3,3-tetrafluoroethyl propionate.

[0019] In summary, the present application includes at least one of the following beneficial technical effects: 1. In the present application, the industrial fluorine-containing monomer hexafluoropropylene is used as the starting material to effectively solve the disadvantages of the difficulty in sourcing raw materials and the corrosiveness of the raw materials, avoid the harsh conditions of the fluorine substitution reaction, and have low requirements on the reaction equipment. A simple addition reaction under base catalysis and a hydrolysis reaction under acid catalysis are carried out, and the use of a large amount of strong base and strong acid is avoided. The reaction is simple and easy to operate, and the process is simple, which is suitable for industrial production. Finally, the target product is prepared by bromination under mild conditions, with high total yield, low cost and high economic benefit; 2. The temperature and time of the hydrolysis reaction are further limited in the present application, thereby improving the yield and purity of ethyl 2,3,3,3-tetrafluoropropionate; 3. The temperature and time of the bromination reaction are further limited in the present application, thereby improving the yield and purity of the final product 2-bromo-2,3,3,3-tetrafluoroethyl propionate. DETAILED DESCRIPTION

[0020] The present application is further described in detail below with reference to the embodiments.

[0021] All raw materials in the examples are commercially available. Example

[0022] Example 1 Embodiment 1 provides a method for synthesizing ethyl 2-bromo-2,3,3,3-tetrafluoropropionate, comprising the following steps: Addition reaction: first add 2kg of ethanol into a 5L stainless steel autoclave, then add 100g of base catalyst, seal the autoclave, start stirring, lower the temperature to 0°C, slowly introduce 2kg of hexafluoropropylene, raise the temperature to 55°C, keep stirring for 2h, distill at atmospheric pressure to 52°C, and collect 2.482kg of 1,1,2,3,3,3-pentafluoropropyl ether; wherein the base catalyst is potassium hydroxide; Hydrolysis reaction: add 1,1,2,3,3,3-pentafluoropropyl ether into a 5L glass kettle, add 2kg of water, lower the temperature to 0°C, add 100g of acid catalyst, raise the temperature to 50°C, keep stirring for 1h, lower the temperature to room temperature, separate the mother liquor into the lower layer product through a separatory funnel, wash the lower layer product with 2kg of water, dry and filter over anhydrous sodium sulfate after separation to obtain 2.049kg of ethyl 2,3,3,3-tetrafluoropropionate; wherein the acid catalyst is concentrated sulfuric acid with a mass concentration of 98%; Bromination reaction: add ethyl 2,3,3,3-tetrafluoropropionate to a 5L glass kettle, lower the temperature to 0°C, drop 2kg of bromination reagent, raise the temperature to 80°C, keep stirring for 2h, and recover ethyl 2,3,3,3-tetrafluoropropionate by atmospheric distillation at 105°C. The bottom liquid is cooled to room temperature and 2kg of water is added for washing. After separation, the liquid is dried over anhydrous sodium sulfate and filtered, and then distilled at 120°C under atmospheric pressure to obtain 2.77kg of ethyl 2-bromo-2,3,3,3-tetrafluoropropionate; the bromination reagent is bromine; the equation for the synthesis of ethyl 2-bromo-2,3,3,3-tetrafluoropropionate is:

[0023] Example 2 The difference between Example 2 and Example 1 is that, for the addition reaction, 2 kg of ethanol was first added to a 5 L stainless steel autoclave, followed by adding 100 g of an alkali catalyst, the autoclave was sealed, stirring was started, the temperature was lowered to 0° C., 2 kg of hexafluoropropylene was slowly introduced, the temperature was raised to 20° C., the mixture was kept warm and stirred for 5 h, and 1,1,2,3,3,3-pentafluoropropyl ether was collected by atmospheric distillation to 52° C.; the remaining steps were consistent with Example 1.

[0024] Example 3 The difference between Example 3 and Example 1 is that, in the hydrolysis reaction, 2.482 kg of 1,1,2,3,3,3-pentafluoropropyl ether is added to a 5 L glass kettle, 2 kg of water is added, the temperature is lowered to 0 ° C, 100 g of acid catalyst is added dropwise, the temperature is raised to 25 ° C, the mixture is stirred for 4 hours, the temperature is lowered to room temperature, the mother liquor is separated into the lower layer product through a separatory funnel, the lower layer product is washed with 2 kg of water, and after separation, it is dried and filtered over anhydrous sodium sulfate to obtain 2,3,3,3-tetrafluoropropionic acid ethyl ester; the remaining steps are consistent with Example 1.

[0025] Example 4 The difference between Example 4 and Example 1 is that, for the bromination reaction, ethyl 2,3,3,3-tetrafluoropropionate is added into a 5L glass kettle, the temperature is lowered to 0°C, 2kg of bromination reagent is added dropwise, the temperature is raised to 55°C, the mixture is stirred for 4h, and ethyl 2,3,3,3-tetrafluoropropionate is recovered by atmospheric distillation at 105°C, the bottom liquid is cooled to room temperature, 2kg of water is added for washing, the liquid is separated, dried over anhydrous sodium sulfate, filtered, and then distilled at 120°C under atmospheric pressure to obtain ethyl 2-bromo-2,3,3,3-tetrafluoropropionate; the remaining steps are consistent with Example 1.

[0026] Example 5 The difference between Example 5 and Example 1 is that, for the addition reaction, 2 kg of ethanol is first added to a 5 L stainless steel autoclave, followed by adding 100 g of an alkali catalyst, the autoclave is sealed, stirring is started, the temperature is lowered to 0° C., 2 kg of hexafluoropropylene is slowly introduced, the temperature is raised to 55° C., the mixture is stirred at this temperature for 2 h, and 1,1,2,3,3,3-pentafluoropropyl ether is collected by atmospheric distillation to 52° C.; wherein the alkali catalyst is sodium hydroxide; and the remaining steps are consistent with Example 1.

[0027] Example 6 The difference between Example 6 and Example 1 is that, in the hydrolysis reaction, 1,1,2,3,3,3-pentafluoropropyl ether is added to a 5L glass kettle, 2kg of water is added, the temperature is lowered to 0°C, 100g of acid catalyst is slowly added, the temperature is raised to 50°C, stirred for 1h, cooled to room temperature, the mother liquor is separated into the lower layer product through a separatory funnel, the lower layer product is washed with 2kg of water, and after separation, it is dried and filtered over anhydrous sodium sulfate to obtain 2,3,3,3-tetrafluoropropionic acid ethyl ester; wherein the acid catalyst is polyphosphoric acid; and the remaining steps are consistent with Example 1.

[0028] Example 7 The difference between Example 7 and Example 1 is that, for the bromination reaction, ethyl 2,3,3,3-tetrafluoropropionate is added into a 5L glass kettle, the temperature is lowered to 0°C, 2kg of bromination reagent is added dropwise, the temperature is raised to 80°C, the mixture is kept warm and stirred for 2h, and ethyl 2,3,3,3-tetrafluoropropionate is recovered by atmospheric distillation at 105°C, the bottom liquid is cooled to room temperature, 2kg of water is added for washing, the liquid is separated, dried over anhydrous sodium sulfate, filtered, and then distilled at 120°C under atmospheric pressure to obtain ethyl 2-bromo-2,3,3,3-tetrafluoropropionate; wherein the bromination reagent is N-bromosuccinimide; and the remaining steps are consistent with Example 1.

[0029] Example 8 Embodiment 8 provides a method for synthesizing ethyl 2-bromo-2,3,3,3-tetrafluoropropionate, comprising the following steps: Addition reaction: first add 2kg of ethanol into a 5L stainless steel autoclave, then add 100g of base catalyst, seal the autoclave, start stirring, lower the temperature to 0°C, slowly introduce 2kg of hexafluoropropylene, raise the temperature to 60°C, keep stirring for 1h, distill at atmospheric pressure to 52°C, and collect 1,1,2,3,3,3-pentafluoropropyl ether; wherein the base catalyst is potassium hydroxide; Hydrolysis reaction: add 1,1,2,3,3,3-pentafluoropropyl ether into a 5L glass kettle, add 2kg of water, lower the temperature to 0°C, add 100g of acid catalyst, raise the temperature to 60°C, keep stirring for 2h, lower the temperature to room temperature, separate the mother liquor into the lower layer product through a separatory funnel, wash the lower layer product with 2kg of water, dry and filter over anhydrous sodium sulfate after separation to obtain 2,3,3,3-tetrafluoropropionic acid ethyl ester; wherein the acid catalyst is concentrated sulfuric acid with a mass concentration of 98%; Bromination reaction: add ethyl 2,3,3,3-tetrafluoropropionate into a 5L glass kettle, lower the temperature to 0°C, drop 2kg of bromination reagent, raise the temperature to 90°C, keep stirring for 1h, and distill at 105°C to recover ethyl 2,3,3,3-tetrafluoropropionate. Cool the bottom liquid to room temperature and add 2kg of water for washing. After separation, dry and filter over anhydrous sodium sulfate, and distill at 120°C to obtain ethyl 2-bromo-2,3,3,3-tetrafluoropropionate; the bromination reagent is bromine.

[0030] Example 9 Embodiment 9 provides a method for synthesizing ethyl 2-bromo-2,3,3,3-tetrafluoropropionate, comprising the following steps: Addition reaction: first add 2kg of ethanol into a 5L stainless steel autoclave, then add 100g of base catalyst, seal the autoclave, start stirring, lower the temperature to 0°C, slowly introduce 2kg of hexafluoropropylene, raise the temperature to 10°C, keep stirring for 8h, distill at atmospheric pressure to 52°C, and collect 1,1,2,3,3,3-pentafluoropropyl ether; wherein the base catalyst is potassium hydroxide; Hydrolysis reaction: add 1,1,2,3,3,3-pentafluoropropyl ether into a 5L glass kettle, add 2kg of water, lower the temperature to 0°C, add 100g of acid catalyst, raise the temperature to 10°C, keep stirring for 6h, lower the temperature to room temperature, separate the mother liquor into the lower layer product through a separatory funnel, wash the lower layer product with 2kg of water, dry and filter with anhydrous sodium sulfate after separation to obtain 2,3,3,3-tetrafluoropropionic acid ethyl ester; wherein the acid catalyst is concentrated sulfuric acid with a mass concentration of 98%; Bromination reaction: add ethyl 2,3,3,3-tetrafluoropropionate into a 5L glass kettle, lower the temperature to 0°C, add 2kg of bromination reagent dropwise, raise the temperature to 30°C, keep stirring for 6h, and distill at 105°C to recover ethyl 2,3,3,3-tetrafluoropropionate. Cool the bottom liquid to room temperature and add 2kg of water for washing. After separation, dry and filter over anhydrous sodium sulfate, and distill at 120°C to obtain ethyl 2-bromo-2,3,3,3-tetrafluoropropionate; the bromination reagent is bromine.

[0031] Comparative Example Comparative Example 1 Comparative Example 1 provides a method for synthesizing ethyl 2-bromo-2,3,3,3-tetrafluoropropionate, comprising the following steps: Dissolve 100 g of 2,3,3,3-tetrafluoropropionic acid in 200 ml of dichloromethane and stir. Add 120 g of bromine dropwise at 30°C, keep warm and stir for 6 hours, distill to 80°C at normal pressure, cool to 60°C, add 30 g of concentrated sulfuric acid and 200 ml of ethanol, raise the temperature to 90°C, keep warm and react for 5 hours, distill to 95°C at normal pressure, cool to 20°C, add 200 ml of saturated sodium carbonate aqueous solution to wash, then wash with 200 ml of saturated brine, separate the liquids, and distill the organic phase under reduced pressure to obtain 128 g of ethyl 2-bromo-2,3,3,3-tetrafluoropropionate.

[0032] Performance test yield: The yield and content of the product in each example, as well as the total yield of the final product ethyl 2-bromo-2,3,3,3-tetrafluoropropionate were tested.

[0033] Table 1 Performance test results of products In combination with Example 1 and Comparative Example 1, the synthesis method in Example 1 obtains a higher yield of 2-bromo-2,3,3,3-tetrafluoropropionic acid ethyl ester. It can be seen that the method in the present application uses industrial fluorine-containing monomer hexafluoropropylene as a starting material, avoids the harsh conditions of the fluorine substitution reaction, does not require high reaction equipment, performs simple base-catalyzed addition reaction and acid-catalyzed hydrolysis reaction, avoids the use of a large amount of strong base and strong acid, the reaction is simple and easy to operate, the process is simple, and it is suitable for industrial production. Finally, the target product is prepared by bromination under mild conditions, with a high total yield and low cost.

[0034] In combination with Example 1-4, Example 8 and Example 9, the yield of 2-bromo-2,3,3,3-tetrafluoropropionic acid ethyl ester obtained in Example 1-4 is higher, and the yield and purity of the products obtained by the addition reaction, hydrolysis reaction and bromination reaction in Example 1-4 are both higher. It can be seen that when synthesizing 2-bromo-2,3,3,3-tetrafluoropropionic acid ethyl ester, the synthesis conditions in Example 1-4 are optimal, so that the final yield of the product is higher.

[0035] In combination with Example 1 and Example 5, the yield of 2-bromo-2,3,3,3-tetrafluoropropionic acid ethyl ester obtained in Example 1 is higher. It can be seen that when hexafluoropropylene and ethanol are used for the addition reaction, the base catalyst is preferably potassium hydroxide, and the yield and purity of 1,1,2,3,3,3-pentafluoropropyl ethyl ether are higher, thereby finally obtaining a higher yield of 2-bromo-2,3,3,3-tetrafluoropropionic acid ethyl ester.

[0036] In combination with Example 1 and Example 6, the yield of 2-bromo-2,3,3,3-tetrafluoropropionic acid ethyl ester obtained in Example 1 is higher. It can be seen that when 1,1,2,3,3,3-pentafluoropropyl ethyl ether is hydrolyzed under the action of an acid catalyst, the acid catalyst is preferably concentrated sulfuric acid with a mass concentration of 98%, and the yield and purity of 2,3,3,3-tetrafluoropropionic acid ethyl ester are higher, thereby finally obtaining a higher yield of 2-bromo-2,3,3,3-tetrafluoropropionic acid ethyl ester.

[0037] In combination with Example 1 and Example 7, the yield of 2-bromo-2,3,3,3-tetrafluoropropionic acid ethyl ester obtained in Example 1 is higher. It can be seen that when 2,3,3,3-tetrafluoropropionic acid ethyl ester and a brominating agent are used for bromination reaction, the brominating agent is preferably bromine, and the yield and purity of the brominated product are higher, thereby finally obtaining a higher yield of 2-bromo-2,3,3,3-tetrafluoropropionic acid ethyl ester.

[0038] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed. However, as long as it is within the scope of the claims of the present application, it shall be protected by the patent law.

Claims

1. A method for synthesizing ethyl 2-bromo-2,3,3,3-tetrafluoropropionate, characterized in that: The following steps are involved: Addition reaction: Hexafluoropropylene and ethanol are subjected to an addition reaction in the presence of a base catalyst to obtain 1,1,2,3,3,3-pentafluoropropyl ether; Hydrolysis reaction: 1,1,2,3,3,3-pentafluoropropyl ethyl ether is hydrolyzed under the action of an acid catalyst to obtain 2,3,3,3-tetrafluoropropionic acid ethyl ester; Bromination reaction: 2,3,3,3-tetrafluoropropionic acid ethyl ester and a brominating agent are subjected to bromination reaction to obtain 2-bromo-2,3,3,3-tetrafluoropropionic acid ethyl ester.

2. A method for synthesizing ethyl 2-bromo-2,3,3,3-tetrafluoropropionate according to claim 1, characterized in that: The synthesis equation of the 2-bromo-2,3,3,3-tetrafluoroethyl propionate is:

3. A method for synthesizing ethyl 2-bromo-2,3,3,3-tetrafluoropropionate according to claim 2, characterized in that: The alkaline catalyst includes one of potassium hydroxide and sodium hydroxide.

4. A method for synthesizing ethyl 2-bromo-2,3,3,3-tetrafluoropropionate according to claim 2, characterized in that: The acid catalyst includes one of concentrated sulfuric acid and polyphosphoric acid.

5. A method for synthesizing ethyl 2-bromo-2,3,3,3-tetrafluoropropionate according to claim 2, characterized in that: The bromination reagent includes one of bromine and N-bromosuccinimide.

6. A method for synthesizing ethyl 2-bromo-2,3,3,3-tetrafluoropropionate according to claim 1, characterized in that: The addition reaction steps are: firstly adding a base catalyst into ethanol, stirring, adding hexafluoropropylene at 0°C, heating to 20-55°C, keeping warm and stirring for 2-5h, and then distilling at normal pressure to obtain 1,1,2,3,3,3-pentafluoropropyl ether.

7. A method for synthesizing ethyl 2-bromo-2,3,3,3-tetrafluoropropionate according to claim 1, characterized in that: The hydrolysis reaction steps are: adding 1,1,2,3,3,3-pentafluoropropyl ethyl ether to water, adding an acid catalyst at 0°C, heating to 25-50°C, keeping warm and stirring for 1-4 hours, and after the reaction is completed, washing the lower layer with water and drying to obtain 2,3,3,3-tetrafluoropropionic acid ethyl ester.

8. A method for synthesizing ethyl 2-bromo-2,3,3,3-tetrafluoropropionate according to claim 1, characterized in that: The bromination reaction steps are: adding ethyl 2,3,3,3-tetrafluoropropionate into a glass kettle, adding a bromination reagent at 0°C, heating to 55-80°C, and stirring for 2-4 hours. After the reaction is completed, distilling at atmospheric pressure to recover ethyl 2,3,3,3-tetrafluoropropionate, washing the bottom liquid with water, and separating the liquid to obtain ethyl 2-bromo-2,3,3,3-tetrafluoropropionate.

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