Preparation method of fluorine-containing acrylate monomer

Abstract

The invention provides a preparation method of a fluorine-containing acrylate monomer, and belongs to the field of organic synthesis. The preparation method provided by the invention comprises the following steps: distilling a solution containing a compound as shown in a formula III and a polymerization inhibitor to obtain a fluorine-containing acrylate monomer, and the polymerization inhibitor selects a specific molecule. By using the preparation method, the product yield can be effectively improved. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to the field of organic synthesis, and particularly to a method for preparing a fluorinated acrylate monomer. Background Art

[0002] The polymer materials prepared from fluorinated acrylates generally have good oil resistance and water resistance, and thus have been widely used in many industrial fields.

[0003] As reported in Chinese Patent CN 112662303A, 1H,1H,9H-hexadecafluorononyl acrylate can be used as a photocurable monomer of a highly water-resistant resin composition for optical fiber coating.

[0004] In the prior art, US Patent US2642416A discloses a method for preparing 1,1-dihydroperfluorooctyl acrylate, which uses 1,1-dihydroperfluoroalkyl alcohol and acryloyl chloride as starting materials for acylation reaction, and the product is obtained by distillation with a yield of 64.3%-92%.

[0005] The applicant found that in the synthesis method disclosed in the above literature, with the increase of the alkyl chain of 1,1-dihydroperfluoroalkyl alcohol, the yield decreased significantly. Especially for the preparation of fluorinated alkyl acrylates with C8-C10 such as 1,1-dihydroperfluorooctyl acrylate and 1,1-dihydroperfluorodecyl acrylate, the yield was only 64.3%-71.7%, which was particularly unfavorable for the industrial production of longer-chain fluorinated alkyl acrylates. Summary of the Invention

[0006] The present invention is made to solve the above problems, and the purpose is to provide a method for preparing a fluorinated acrylate monomer with a long carbon chain in high yield.

[0007] The present invention provides a method for preparing a fluorinated acrylate monomer, which has the following characteristics and includes the following steps:

[0008] Distill a solution containing a compound of formula III and a polymerization inhibitor to obtain a fluorinated acrylate monomer;

[0009]

[0010] Among them, the polymerization inhibitor is

[0011] R 1 and R 2 are independently H or C 1-6 alkyl, and n = 3 or 4;

[0012] When n = 3, A is selected from any one of the following formulas:

[0013]

[0014] R 3 、R 4 、R 5 are independently H or C 1-6 alkyl;

[0015] When n = 4, A is

[0016] In the preparation method of the fluorinated acrylate monomer provided by the present invention, it may further have the following feature: the preparation method of the compound of formula III includes the following steps: the compound of formula I reacts with the compound of formula II in the presence of a catalyst and a solvent to obtain the compound of formula III;

[0017]

[0018] X is chlorine or bromine.

[0019] In the preparation method of the fluorinated acrylate monomer provided by the present invention, it may further have the following feature: wherein, the catalyst is an organic base or an inorganic base; preferably, the catalyst is an inorganic base;

[0020] The organic base is selected from any one or more of pyridine, triethylamine, N,N-dimethylaniline, 4-dimethylaminopyridine, diisopropylethylamine, 2,3,5-trimethylpyridine or hexamethylphosphoric triamide;

[0021] The inorganic base is selected from any one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate or cesium carbonate.

[0022] In the preparation method of the fluorinated acrylate monomer provided by the present invention, it may further have the following feature: R 1 and R 2 among them, the C 1-6 alkyl may be C 1-4 alkyl, preferably methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl or tert-butyl, more preferably tert-butyl.

[0023] In the preparation method of the fluorinated acrylate monomer provided by the present invention, it may further have the following feature: R 3 、R 4 and R 5 among them, the C 1-6 alkyl may be C 1-4 alkyl, preferably methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl or tert-butyl, more preferably methyl.

[0024] In the method for preparing the fluorinated acrylate monomer provided by the present invention, it may further have the following feature: The inhibitor is R 1 and R 2 are independently H or C 1-4 alkyl, and n = 3 or 4;

[0025] When n = 3, A is selected from any one of the following formulas:

[0026]

[0027] R 3 and R 4 and R 5 are independently H or C 1-4 alkyl;

[0028] When n = 4, A is

[0029] In the method for preparing the fluorinated acrylate monomer provided by the present invention, it may further have the following feature: Among them, the inhibitor is selected from any one or more of the following compounds:

[0030]

[0031] In the method for preparing the fluorinated acrylate monomer provided by the present invention, it may further have the following feature: The reaction is carried out in the presence of a phase transfer catalyst.

[0032] In the method for preparing the fluorinated acrylate monomer provided by the present invention, it may further have the following feature: The phase transfer catalyst can be a quaternary ammonium salt, preferably benzyltriethylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium chloride or tetrabutylammonium hydrogensulfate, and more preferably tetrabutylammonium chloride.

[0033] In the method for preparing the fluorinated acrylate monomer provided by the present invention, it may further have the following feature: The mass ratio of the phase transfer catalyst to the compound of formula I can be 1:(10 - 30), preferably 1:20.

[0034] In the method for preparing the fluorinated acrylate monomer provided by the present invention, it may further have the following feature: The solution containing the compound of formula III and the inhibitor is a solution in which the compound of formula III and the inhibitor are dissolved in a solvent.

[0035] In the method for preparing the fluorinated acrylate monomer provided by the present invention, it may further have the following feature: Among them, the solvent is selected from any one or more of dichloromethane, dichloroethane, chloroform, benzene, toluene, acetonitrile, ethyl acetate, petroleum ether, tetrahydrofuran or dimethyl sulfoxide.

[0036] In the method for preparing the fluorinated acrylate monomer provided by the present invention, it may further have the following characteristics: wherein, the mass-volume ratio of the compound of formula I to the solvent is 1 g:(2 - 10) mL, preferably 1 g:6 mL.

[0037] In the method for preparing the fluorinated acrylate monomer provided by the present invention, it may further have the following characteristics: wherein, the molar ratio of the compound of formula I to the compound of formula II is 1:(1 - 2), preferably 1:(1 - 1.5), for example 1:1.3.

[0038] In the method for preparing the fluorinated acrylate monomer provided by the present invention, it may further have the following characteristics: wherein, the molar ratio of the compound of formula I to the catalyst is 1:(1 - 2), preferably 1:1.5.

[0039] In the method for preparing the fluorinated acrylate monomer provided by the present invention, it may further have the following characteristics: wherein, the preparation method of the compound of formula III includes the following steps:

[0040] The compound of formula I and the compound of formula II react in the presence of a catalyst and a solvent, and after the reaction is completed, a reaction solution is obtained;

[0041] The reaction solution is subjected to an operation of reducing the ion content by using a solvent extraction method and / or an adsorption method to obtain a solution containing the compound of formula III;

[0042] The inhibitor is added to the solution containing the compound of formula III to obtain a solution containing the compound of formula III and the inhibitor,

[0043] The solution containing the compound of formula III and the inhibitor is rectified to obtain the compound of formula III.

[0044] In the method for preparing the fluorinated acrylate monomer provided by the present invention, it may further have the following characteristics: wherein, the preparation method of the compound of formula III includes the following steps:

[0045] The compound of formula I and the compound of formula II react in the presence of a catalyst, a phase transfer catalyst and a solvent, and after the reaction is completed, a reaction solution is obtained;

[0046] The reaction solution is subjected to an operation of reducing the ion content by using a solvent extraction method and / or an adsorption method to obtain a solution containing the compound of formula III;

[0047] The inhibitor is added to the solution containing the compound of formula III to obtain a solution containing the compound of formula III and the inhibitor,

[0048] The solution containing the compound of formula III and the inhibitor is rectified to obtain the compound of formula III.

[0049] In the method for preparing the fluorinated acrylate monomer provided by the present invention, it may further have the following characteristics: Among them, the solvent extraction method is used to operate on the reaction solution to reduce the ion content.

[0050] The solvent extraction method is to wash the reaction solution with a washing solution.

[0051] The washing solution is water, an aqueous sodium bicarbonate solution or an aqueous citric acid solution.

[0052] In the method for preparing the fluorinated acrylate monomer provided by the present invention, it may further have the following characteristics: Among them, in the operation of reducing the ion content of the reaction solution by using the solvent extraction method, the volume ratio of the water or aqueous solution used to the reaction solution is (1-3):(1-3), preferably (2-3):1.

[0053] In the method for preparing the fluorinated acrylate monomer provided by the present invention, it may further have the following characteristics: Among them, the adsorption method is to adsorb the ions in the reaction solution with an ion adsorption material, and the ion adsorption material is selected from any one or more of ion exchange resins, double metal oxides (such as Ca-Al oxides, Mg-Al oxides), hydrotalcite materials (such as magnesium-aluminum hydrotalcite, aluminum-zinc hydrotalcite), carbon-based electrode materials, molecular sieves or activated carbon.

[0054] In the method for preparing the fluorinated acrylate monomer provided by the present invention, it may further have the following characteristics: Among them, the mass ratio of the inhibitor to the compound of formula I is (0.01-5):500, preferably (0.01-1):500, for example 0.1:500.

[0055] In the method for preparing the fluorinated acrylate monomer provided by the present invention, it may further have the following characteristics: Among them, the conditions for rectifying to obtain the fluorinated acrylate monomer are an internal pressure of 1-5 mmHg and a top temperature of 80-100 °C.

[0056] Functions and effects of the invention

[0057] According to the method for preparing the fluorinated acrylate monomer involved in the present invention, because a compound with the structural formula is creatively added as an inhibitor before distillation, therefore, the present invention unexpectedly and effectively improves the yield of the compound. Detailed implementation manners

[0058] In order to make the technical means, creative features, achieved purposes and effects achieved by the present invention easy to understand, the present invention will be specifically described below in conjunction with examples.

[0059] In the following examples, unless otherwise specified, each raw material is a commercially available product.

[0060] In the following embodiments, inhibitor A is

[0061] Inhibitor B is

[0062] Inhibitor C is

[0063] In the following embodiments, the detection of chloride ion content was carried out using the same commercially available ion chromatograph.

[0064] <Example 1>

[0065] Preparation method of fluorinated acrylate monomer solution

[0066] This example provides a preparation method of a fluorinated acrylate monomer solution, and the reaction formula is as follows:

[0067]

[0068] It includes the following steps:

[0069] Dissolve 50 g of compound I (0.116 mol, 1.0 eq) in 300 mL of tetrahydrofuran, add 7.0 g of sodium hydroxide (0.175 mol, 1.5 eq) and 2.5 g of tetrabutylammonium chloride, control the temperature at 10 °C, keep stirring, and dropwise add 13.7 g of acryloyl chloride (0.151 mol, 1.3 eq). After the dropwise addition is completed, keep the temperature at 0 - 10 °C and continue the reaction for 3 h to obtain a reaction solution; take a sample of the reaction solution and send it for GC detection. The detection result shows that the conversion rate is greater than 99%;

[0070] Add a washing solution to the reaction solution for washing, wash three times, and the amount of the washing solution used each time is 150 mL to obtain a solution containing compound III.

[0071] Use an ion chromatograph to detect the chloride ion content of the solution containing compound III obtained after washing with different washing solutions.

[0072] The detection results are shown in Table 1.

[0073] Table 1 Detection of chloride ion content

[0074] Serial number Washing liquid Chloride ion content (ppm) 1 Deionized water 2813.5 2 5 wt% sodium bicarbonate aqueous solution 41.6 3 5 wt% citric acid aqueous solution 15.8

[0075] As can be seen from the above table, after washing with a 5 wt% aqueous sodium bicarbonate solution or a 5 wt% aqueous citric acid solution, the chloride ion content can be reduced to an acceptable level.

[0076] <Example 2>

[0077] Preparation method of fluorinated acrylate monomer

[0078] This example provides a method for preparing a fluorinated acrylate monomer solution, and the reaction formula is as follows:

[0079]

[0080] It includes the following steps:

[0081] Dissolve 500 g of compound I (1.16 mol, 1.0 eq) in 3 L of tetrahydrofuran, add 70 g of sodium hydroxide (1.75 mol, 1.5 eq) and 25 g of tetrabutylammonium chloride. Control the temperature at 10 °C, keep stirring, and dropwise add 137 g of acryloyl chloride (1.51 mol, 1.3 eq). After the dropwise addition is completed, keep the temperature at 0 - 10 °C and continue the reaction for 3 h to obtain a reaction solution;

[0082] Add 5 wt% citric acid aqueous solution to the reaction solution for washing, wash three times in total, and the amount of 5 wt% citric acid aqueous solution used each time is 1.5 L to obtain a solution containing compound III;

[0083] Add 0.1 g of inhibitor A to the solution containing compound III, mix evenly to obtain a solution containing compound III and the inhibitor;

[0084] Heat the solution containing compound III and the inhibitor to 40 °C, distill off the solvent under reduced pressure, and perform rectification under the conditions of 2 mmHg and a top temperature of 90 °C to collect 481 g of compound III, with a yield of 85.3% and a purity of 99.2%.

[0085] <Example 3>

[0086] Preparation method of fluorinated acrylate monomer

[0087] This example provides a method for preparing a fluorinated acrylate monomer solution, and the reaction formula is as follows:

[0088]

[0089] It includes the following steps:

[0090] Dissolve 500 g of compound I (1.16 mol, 1.0 eq) in 3 L of tetrahydrofuran, add 70 g of sodium hydroxide (1.75 mol, 1.5 eq) and 25 g of tetrabutylammonium chloride. Control the temperature at 10 °C, keep stirring, and dropwise add 137 g of acryloyl chloride (1.51 mol, 1.3 eq). After the dropwise addition is completed, keep the temperature at 0 - 10 °C and continue the reaction for 3 h to obtain a reaction solution;

[0091] Add 5 wt% citric acid aqueous solution to the reaction solution for washing, wash three times in total, and the amount of 5 wt% citric acid aqueous solution used each time is 1.5 L to obtain a solution containing compound III;

[0092] Add 0.1 g of inhibitor B to the solution containing the compound of formula III, mix well to obtain a solution containing the compound of formula III and the inhibitor.

[0093] Heat the solution containing the compound of formula III and the inhibitor to 40°C, distill off the solvent under reduced pressure, and perform rectification under the conditions of 2 mmHg and a top temperature of 90°C to collect 449 g of compound III with a yield of 79.8% and a purity of 99.1%.

[0094] <Example 4>

[0095] Preparation method of fluorinated acrylate monomer

[0096] This example provides a preparation method of a fluorinated acrylate monomer solution, and the reaction formula is as follows:

[0097]

[0098] The method includes the following steps:

[0099] Dissolve 500 g of compound I (1.16 mol, 1.0 eq) in 3 L of tetrahydrofuran, add 70 g of sodium hydroxide (1.75 mol, 1.5 eq) and 25 g of tetrabutylammonium chloride, control the temperature at 10°C, keep stirring, and dropwise add 137 g of acryloyl chloride (1.51 mol, 1.3 eq). After the addition is completed, keep the temperature at 0 - 10°C and continue to react for 3 h to obtain a reaction solution.

[0100] Add 5 wt% citric acid aqueous solution to the reaction solution for washing, wash three times in total, and the amount of 5 wt% citric acid aqueous solution used each time is 1.5 L to obtain a solution containing the compound of formula III.

[0101] Add 0.1 g of inhibitor C to the solution containing the compound of formula III, mix well to obtain a solution containing the compound of formula III and the inhibitor.

[0102] Heat the solution containing the compound of formula III and the inhibitor to 40°C, distill off the solvent under reduced pressure, and perform rectification under the conditions of 2 mmHg and a top temperature of 90°C to collect 467 g of compound III with a yield of 82.8% and a purity of 99.1%.

[0103] <Example 5>

[0104] Preparation method of fluorinated acrylate monomer

[0105] This example provides a preparation method of a fluorinated acrylate monomer solution, and the reaction formula is as follows:

[0106]

[0107] It includes the following steps:

[0108] Dissolve 500 g of Compound I (1.16 mol, 1.0 eq) in 3 L of tetrahydrofuran, add 70 g of sodium hydroxide (1.75 mol, 1.5 eq), 25 g of tetrabutylammonium chloride, and 0.1 g of inhibitor A. Control the temperature at 10 °C, keep stirring, and dropwise add 137 g of acryloyl chloride (1.51 mol, 1.3 eq). After the addition is complete, keep the temperature at 0 - 10 °C and continue the reaction for 3 h to obtain a reaction solution;

[0109] Add 5 wt% citric acid aqueous solution to the reaction solution for washing, wash three times in total, and the amount of 5 wt% citric acid aqueous solution used each time is 1.5 L to obtain a solution containing Compound III;

[0110] Heat the solution containing Compound III to 40 °C, distill off the solvent under reduced pressure, and carry out rectification under the conditions of 2 mmHg and a top temperature of 90 °C. Collect 420 g of Compound III, with a yield of 74.7% and a purity of 98.8%.

[0111] <Comparative Example 1>

[0112] Preparation method of fluorinated acrylate monomer

[0113] This comparative example provides a preparation method of a fluorinated acrylate monomer solution, and the reaction formula is as follows:

[0114]

[0115] Dissolve 500 g of Compound I (1.16 mol, 1.0 eq) in 3 L of tetrahydrofuran, add 70 g of sodium hydroxide (1.75 mol, 1.5 eq) and 25 g of tetrabutylammonium chloride. Control the temperature at 10 °C, keep stirring, and dropwise add 137 g of acryloyl chloride (1.51 mol, 1.3 eq). After the addition is complete, keep the temperature at 0 - 10 °C and continue the reaction for 3 h to obtain a reaction solution;

[0116] Add 5 wt% citric acid aqueous solution to the reaction solution for washing, wash three times in total, and the amount of 5 wt% citric acid aqueous solution used each time is 1.5 L to obtain a solution containing Compound III;

[0117] Add 0.1 g of 2,6 - di - tert - butylphenol to the solution containing Compound III, mix evenly to obtain a solution containing Compound III and an inhibitor;

[0118] Heat the solution containing Compound III and the inhibitor to 40 °C, distill off the solvent under reduced pressure, and carry out rectification under the conditions of 2 mmHg and a top temperature of 90 °C. Collect 314 g of Compound III, with a yield of 55.9%.

[0119] <Comparative Example 2>

[0120] Preparation method of fluorinated acrylate monomer

[0121] This comparative example provides a preparation method of a fluorinated acrylate monomer solution, and the reaction formula is as follows:

[0122]

[0123] Dissolve 500 g of compound I (1.16 mol, 1.0 eq) in 3 L of tetrahydrofuran, add 70 g of sodium hydroxide (1.75 mol, 1.5 eq) and 25 g of tetrabutylammonium chloride, control the temperature at 10 °C, keep stirring, and dropwise add 137 g of acryloyl chloride (1.51 mol, 1.3 eq). After the dropping is completed, keep the temperature at 0 - 10 °C and continue to react for 3 h to obtain a reaction solution;

[0124] Add 5 wt% aqueous citric acid solution to the reaction solution for washing, wash three times in total, and the amount of 5 wt% aqueous citric acid solution used each time is 1.5 L to obtain a solution containing compound III;

[0125] Add 0.1 g of hydroquinone to the solution containing compound III, mix evenly to obtain a solution containing compound III and a polymerization inhibitor;

[0126] Heat the solution containing compound III and the polymerization inhibitor to 40 °C, distill off the solvent under reduced pressure, and perform rectification under the conditions of 2 mmHg and a top temperature of 90 °C to collect 340 g of compound III, with a yield of 60.5%.

[0127] <Comparative Example 3>

[0128] Preparation method of fluorinated acrylate monomer

[0129] This comparative example provides a preparation method of a fluorinated acrylate monomer solution, and the reaction formula is as follows:

[0130]

[0131] Dissolve 500 g of compound I (1.16 mol, 1.0 eq) in 3 L of tetrahydrofuran, add 70 g of sodium hydroxide (1.75 mol, 1.5 eq) and 25 g of tetrabutylammonium chloride, control the temperature at 10 °C, keep stirring, and dropwise add 137 g of acryloyl chloride (1.51 mol, 1.3 eq). After the dropping is completed, keep the temperature at 0 - 10 °C and continue to react for 3 h to obtain a reaction solution;

[0132] Add 5 wt% aqueous citric acid solution to the reaction solution for washing, wash three times in total, and the amount of 5 wt% aqueous citric acid solution used each time is 1.5 L to obtain a solution containing compound III;

[0133] Add 1 g of hydroquinone to the solution containing the compound of formula III, and mix evenly to obtain a solution containing the compound of formula III and an inhibitor.

[0134] Heat the solution containing the compound of formula III and the inhibitor to 40 °C, distill off the solvent under reduced pressure, and perform rectification under the conditions of 2 mmHg and a top temperature of 90 °C to collect 366 g of compound III with a yield of 65.1%.

[0135] <Comparative Example 4>

[0136] Preparation method of fluorinated acrylate monomer

[0137] This example provides a preparation method of a fluorinated acrylate monomer solution, and the reaction formula is as follows:

[0138]

[0139] It includes the following steps:

[0140] Dissolve 500 g of compound I (1.16 mol, 1.0 eq) in 3 L of tetrahydrofuran, add 70 g of sodium hydroxide (1.75 mol, 1.5 eq), 25 g of tetrabutylammonium chloride, and 1 g of hydroquinone. Control the temperature at 10 °C, keep stirring, and dropwise add 137 g of acryloyl chloride (1.51 mol, 1.3 eq). After the addition is completed, keep the temperature at 0 - 10 °C and continue to react for 3 h to obtain a reaction solution.

[0141] Add 5 wt% aqueous citric acid solution to the reaction solution for washing, wash three times in total, and the amount of 5 wt% aqueous citric acid solution used each time is 1.5 L to obtain a solution containing the compound of formula III.

[0142] Heat the solution containing the compound of formula III to 40 °C, distill off the solvent under reduced pressure, and perform rectification under the conditions of 2 mmHg and a top temperature of 90 °C to collect 295 g of compound III with a yield of 52.5%.

[0143] Functions and effects of the examples

[0144] According to the preparation method of the fluorinated acrylate monomer involved in the above examples, because a structure formula of The compound as a polymerization inhibitor, especially the polymerization inhibitors such as polymerization inhibitor A, polymerization inhibitor B and polymerization inhibitor C are selected. Therefore, the applicant unexpectedly found that only one-thousandth of the above polymerization inhibitor of the starting material is required at least to increase the yield of the target compound to 74.7%-85.3%. Compared with the distillation conditions using traditional polymerization inhibitors hydroquinone and 2,6-di-tert-butylphenol, the yield is increased by about 20%. According to the applicant's speculation, this may be because the boiling points of hydroquinone and 2,6-di-tert-butylphenol are close to that of the target compound. During the distillation process, hydroquinone or 2,6-di-tert-butylphenol may be distilled out earlier than the product or distilled out simultaneously with the product, which may cause the polymerization inhibitor to fail to play a polymerization inhibition role during the distillation process, thus reducing the reaction yield. However, the boiling points of the polymerization inhibitors selected in the above examples are quite different from the boiling point of the target compound, and there is no such problem. Therefore, it can play a good polymerization inhibition role to increase the yield of the target product.

[0145] Furthermore, the applicant selected acryloyl chloride as the starting material and sodium hydroxide as the catalyst. Therefore, the reaction can be well converted completely even without the participation of a polymerization inhibitor, and no significant polymerization by-products are generated.

[0146] Furthermore, the applicant found that adding the polymerization inhibitor before distillation has a better effect on increasing the yield than adding the polymerization inhibitor before the reaction. This may be because the phenolic hydroxyl group in the polymerization inhibitor may participate in the reaction, resulting in a decrease or loss of its polymerization inhibition performance.

[0147] Furthermore, the applicant found that washing with an aqueous citric acid solution or an aqueous sodium bicarbonate solution after the reaction can reduce the chloride ion content to a certain extent, thereby improving the product quality.

[0148] The above embodiments are preferred cases of the present invention and are not used to limit the protection scope of the present invention.

Claims

1. A preparation method of a fluorinated acrylate monomer, characterized in that, It includes the following steps: Distill the solution containing the compound of formula III and the inhibitor to obtain the fluorinated acrylate monomer; Among them, the inhibitor is R 1 and R 2 are each independently selected from H or C 1-6 alkyl, where n = 3 or 4 When n = 3, A is selected from any one of the following formulas: R 3 、R 4 、R 5 are each independently H or C 1-6 alkyl group, When n = 4, A is 2. The preparation method of the fluorinated acrylate monomer according to claim 1, characterized in that: The preparation method of the compound of formula III includes the following steps: The compound of formula I reacts with the compound of formula II in the presence of a catalyst and a solvent to obtain the compound of formula III; X is chlorine or bromine.

3. The preparation method of the fluorinated acrylate monomer according to claim 2, wherein: Among them, The catalyst is an organic base or an inorganic base, The organic base is selected from any one or more of pyridine, triethylamine, N,N-dimethylaniline, 4-dimethylaminopyridine, diisopropylethylamine, 2,3,5-trimethylpyridine or hexamethylphosphoric triamide, The inorganic base is selected from any one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate or cesium carbonate.

4. The preparation method of the fluorinated acrylate monomer according to claim 3, wherein: Among them, The catalyst is an inorganic base; And / or, the reaction is carried out in the presence of a phase transfer catalyst.

5. The preparation method of the fluorinated acrylate monomer according to claim 2, wherein: Among them, The solvent is selected from any one or more of dichloromethane, dichloroethane, chloroform, benzene, toluene, acetonitrile, ethyl acetate, petroleum ether, tetrahydrofuran or dimethyl sulfoxide.

6. The preparation method of the fluorinated acrylate monomer according to claim 2, wherein Among them, The molar ratio of the compound of formula I to the compound of formula II is 1:(1 - 2); And / or, the molar ratio of the compound of formula I to the catalyst is 1:(1 - 2).

7. The preparation method of the fluorinated acrylate monomer according to claim 1, It is characterized in that Among them, the preparation method of the compound of formula III includes the following steps: The compound of formula I reacts with the compound of formula II in the presence of a catalyst and a solvent, and after the reaction ends, a reaction solution is obtained; Use the solvent extraction method and / or the adsorption method to operate on the reaction solution to reduce the ion content, and obtain a solution containing the compound of formula III; Add the inhibitor to the solution containing the compound of formula III to obtain a solution containing the compound of formula III and the inhibitor, Rectify the solution containing the compound of formula III and the inhibitor to obtain the compound of formula III.

8. The preparation method of the fluorinated acrylate monomer according to claim 7, wherein Among them, Use the solvent extraction method to operate on the reaction solution to reduce the ion content, The solvent extraction method is to wash the reaction solution with a washing solution, The washing solution is any one or more of water, an aqueous sodium bicarbonate solution or an aqueous citric acid solution.

9. The preparation method of the fluorinated acrylate monomer according to claim 7, wherein Among them, The mass ratio of the inhibitor to the compound of formula I is (0.01 - 5):

500.

10. The preparation method of the fluorinated acrylate monomer according to claim 7, wherein Among them, The conditions for rectifying to obtain the fluorinated acrylate monomer are an internal pressure of 1 - 5 mmHg and a top temperature of 80 - 100 °C.

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