A method of synthesizing fluorinated esters

Abstract

The application discloses a kind of fixed bed continuous gas phase catalytic fluorination synthesis fluorinated ester method, which comprises the following steps: 1) using fluoride and carrier is granulated, dried, activated to obtain fluorination agent, 2) the fluorination agent is loaded in fixed bed reactor, under nitrogen atmosphere, after heating and gasification of alkene ester, with fluorine gas is separately introduced into the fixed bed reactor with supported catalyst, catalytic fluorination reaction is carried out at temperature 50-400 DEG C, after reaction, gas is condensed and liquefied, rectification is obtained fluorinated carbonate or fluorinated carboxylic acid ester.The method shortens the reaction time, significantly improves the reaction efficiency, and is suitable for industrial production.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of fine fluorinated chemical industry, and particularly relates to a method for synthesizing fluorinated ester through fixed-bed continuous gas-phase catalytic fluorination. BACKGROUND

[0002] In recent years, the continuous expansion of the scale of downstream industries such as lithium battery industry and new energy vehicles has led to the increasing demand for safety, cycle life and energy density of lithium batteries, and the demand for electrolyte additives has increased year by year.

[0003] The fluorinated carboxylate ester has a high flash point and is suitable for being used as a low-temperature co-solvent of the electrolyte of the lithium ion battery, and can be used to improve the performance of the battery under low-temperature conditions and prevent the structural degradation of the electrode material, so that the battery has better cycle performance.

[0004] For the synthesis route of the fluorinated ester, the following methods are mainly used: (1) using a metal carboxylate to replace a fluorinated halogenated alkyl; (2) using a strong acid as a catalyst to catalyze an esterification reaction; (3) using a fluorinated acyl fluoride to esterify an alcohol to generate a fluorinated ester; (4) using a reducing agent to reduce a chlorofluoroester to prepare a fluorinated ester; (5) using a fluorinated nitrile to catalyze the preparation of a fluorinated ester; and (6) using fluorine gas to fluorinate to prepare a fluorinated ester.

[0005] In the above preparation methods, the method (1) may need to use an added catalyst or an accelerator to promote the reaction, which may cause impurities in the product; in the method (2), the residual strong acid needs to be neutralized after the esterification reaction is completed, which may cause environmental pollution, and the strong acid catalyst may cause a side reaction to generate an acidic impurity that is harmful to the lithium ion battery; in the method (3), the fluorinated acyl fluoride is expensive and difficult to prepare, the process flow is long, and a large amount of byproduct hydrofluoric acid is generated in the fluorinated carboxylate esterification process; in the method (4), the production cost is high; in the method (5), the fluorinated nitrile method has the advantages of simple process and high yield, but has the disadvantages of difficult to obtain the raw material fluorinated nitrile and high production cost; and in the method (6), the fluorine gas directly generates the fluorinated ester, the reaction flow is short, and the method meets the economic production requirement, but the fluorine gas is active and a byproduct is often generated.

[0006] Based on this, the present application is developed. SUMMARY

[0007] The present application aims to overcome the defects of the prior art and provide a method for synthesizing fluorinated ester through fixed-bed continuous gas-phase catalytic fluorination, which has the advantages of simple process, low cost and few side reactions.

[0008] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0009] A supported catalyst mainly consists of an active component and a carrier, wherein the mass ratio of the active component to the carrier is 1:1-50, and the active component is one or more of fluorinated nickel, fluorinated chromium, fluorinated cobalt, fluorinated manganese, fluorinated arsenic, etc.

[0010] Specifically, the carrier can be one or more of activated carbon, molecular sieve, alumina, graphite, pumice, etc.

[0011] The application provides a preparation method of the supported catalyst, which comprises the following steps: uniformly mixing the active component and the carrier, granulating, sieving, heating at 70-150 DEG C for 5-15 h, and then calcining at 300-500 DEG C for 5-15 h.

[0012] The application further provides a method for synthesizing fluorinated ester by using the supported catalyst to perform fixed-bed continuous gas-phase catalytic fluorination, which comprises the following steps:

[0013] After the olefinic ester is heated and gasified under a nitrogen atmosphere, the gas is introduced into a fixed-bed reactor containing the supported catalyst, and a catalytic fluorination reaction is performed at a temperature of 50-400 DEG C; after the reaction is completed, the gas is condensed and liquefied, and then rectified to obtain fluorinated ester (fluorinated carbonate or fluorinated carboxylic acid ester).

[0014] Specifically, the molar ratio of the olefinic ester to fluorine gas introduced into the fixed-bed reactor is 1:0.5-2.

[0015] Further, the mass ratio of the olefinic ester to the active component of the supported catalyst is 1:0.02-0.5.

[0016] Further, the residence time of the olefinic ester and fluorine gas in the fixed-bed reactor is 3-30 s.

[0017] Further, the structure of the olefinic ester is R1R2C=CR3C(O)OR4 or R1R2C=CR3CO2OR4, and R1, R2, R3 and R4 are independently selected from CmH(2m+1-n)Xn, wherein m is a non-negative integer, n is an integer of 0-2m+1, and X is one of fluorine, chlorine and bromine.

[0018] Compared with the prior art, the application has the following beneficial effects:

[0019] 1) Compared with the prior art, the application continuously introduces the gasified gas of fluorine and olefinic ester into a fixed-bed reactor to perform a gas-phase reaction, thereby shortening the reaction time, significantly improving the reaction efficiency, and obtaining fluorinated carboxylic acid ester or fluorinated carbonate with a purity of more than 93% and a yield of up to 83%.

[0020] 2) The method of the present application is efficient for synthesis by continuous gas phase method, and is convenient for industrial production. DETAILED DESCRIPTION

[0021] The present application will be described in detail below with specific examples. It is necessary to point out that the following examples are only used to further illustrate the present application, and cannot be understood as limiting the scope of protection of the present application. Some non-essential improvements and adjustments of the present application made by those skilled in the art according to the content of the present application still fall within the scope of protection of the present application.

[0022] In the following examples, the raw materials used are ordinary commercially available products that can be directly purchased, and the processes not described in detail can be carried out using conventional techniques in the art.

[0023] Example 1:

[0024] A method for synthesizing fluorinated ester by using the supported catalyst in a fixed bed continuous gas phase catalytic fluorination, comprising the following steps:

[0025] 200g of the supported catalyst (the mass ratio of the enoic ester to the active component of the supported catalyst is 1:0.05) was loaded into a fixed bed reactor, the internal gas of the fixed bed reactor was replaced with high-purity nitrogen to ensure that the reaction was carried out in a nitrogen atmosphere, fluorine gas and enoic ester (CF3)2C=CFCOOCH3 after being heated and vaporized were mixed with nitrogen according to a volume ratio of 1:5, and were introduced into the fixed bed reactor according to a molar ratio of 1:1, the reaction temperature was controlled at 140℃, the residence time of the mixed gas was 20 seconds, the gas at the outlet was condensed and liquefied, and was distilled under normal pressure, the fraction of 115-120℃ was collected, and fluorinated ester (CF3)2CFCF2COOCH3 was obtained, with a purity of 98% and a yield of 82%. NMR 1 H (CDCl3): 3.7(s, 3H).

[0026] The supported catalyst used in this example is mainly composed of an active component and a carrier, wherein the mass ratio of the active component to the carrier is 1:50, the active component is nickel fluoride, and the carrier is activated carbon.

[0027] The preparation method of the above supported catalyst can be carried out using conventional methods in the art, and specific reference can be made to the following: the active component and the carrier are uniformly mixed, granulated, passed through a 100 mesh sieve, heated at 100℃ for 10h, and then calcined at 400℃ for 8h to obtain the supported catalyst.

[0028] Example 2:

[0029] The 200 g of supported catalyst (mass ratio of the olefin ester to the active component of the supported catalyst is 1:0.08) is loaded into a fixed bed reactor, the internal gas of the fixed bed reactor is replaced with high-purity nitrogen to ensure that the reaction is carried out in a nitrogen atmosphere, fluorine gas and the heated and vaporized olefin ester (CF3)2C=CFCOOCH3 are mixed with nitrogen at a volume ratio of 1:5, and are introduced into the fixed bed reactor at a molar ratio of 1:1, the reaction temperature is controlled at 140°C, the mixed gas reaction residence time is 20 seconds, the outlet gas is condensed and liquefied, and is distilled under normal pressure, and the fraction of 115-120°C is collected to obtain the fluoroester (CF3)2CFCF2COOCH3; detection shows that the purity is 95% and the yield is 80%.

[0030] The supported catalyst used in the example mainly consists of an active component and a carrier, wherein the mass ratio of the active component to the carrier is 1:30, the active component is chromium fluoride, and the carrier is activated carbon. The preparation method of the supported catalyst is referred to Example 1.

[0031] Example 3

[0032] The 200 g of supported catalyst (mass ratio of the olefin ester to the active component of the supported catalyst is 1:0.08) is loaded into a fixed bed reactor, the internal gas of the fixed bed reactor is replaced with high-purity nitrogen to ensure that the reaction is carried out in a nitrogen atmosphere, fluorine gas and the heated and vaporized olefin ester (CF3)2C=CFCOOCH3 are mixed with nitrogen at a volume ratio of 1:5, and are introduced into the fixed bed reactor at a molar ratio of 1:1, the reaction temperature is controlled at 140°C, the mixed gas reaction residence time is 20 seconds, the outlet gas is condensed and liquefied, and is distilled under normal pressure, and the fraction of 115-120°C is collected to obtain the fluoroester (CF3)2CFCF2COOCH3; detection shows that the purity is 95% and the yield is 80%.

[0033] The supported catalyst used in the example mainly consists of an active component and a carrier, wherein the mass ratio of the active component to the carrier is 1:30, the active component is chromium fluoride, and the carrier is activated carbon. The preparation method of the supported catalyst is referred to Example 1.

[0034] Example 4

[0035] The supported catalyst (mass ratio of the olefin ester to the active component of the supported catalyst was 1:0.2) was loaded into a fixed bed reactor, the internal gas of the fixed bed reactor was replaced with high-purity nitrogen to ensure that the reaction was carried out in a nitrogen atmosphere, fluorine gas and the heated and vaporized olefin ester (CF3)2C=CFCOOCH3 were mixed with nitrogen at a volume ratio of 1:5, and were introduced into the fixed bed reactor at a molar ratio of 1:1, the reaction temperature was controlled at 120°C, the mixed gas reaction residence time was 20 seconds, the outlet gas was condensed and liquefied, and was distilled under normal pressure, and the fraction with a boiling point of 115-120°C was collected to obtain the fluoro ester (CF3)2CFCF2COOCH3, the purity was 93%, and the yield was 75%.

[0036] The supported catalyst used in the example mainly consisted of an active component and a carrier, wherein the mass ratio of the active component to the carrier was 1:50, the active component was cobalt fluoride, and the carrier was activated carbon. The preparation method of the supported catalyst referred to example 1.

[0037] Example 5

[0038] The supported catalyst (mass ratio of the olefin ester to the active component of the supported catalyst was 1:0.2) was loaded into a fixed bed reactor, the internal gas of the fixed bed reactor was replaced with high-purity nitrogen to ensure that the reaction was carried out in a nitrogen atmosphere, fluorine gas and the heated and vaporized olefin ester (CF3)2C=CFCOOEt were mixed with nitrogen at a volume ratio of 1:5, and were introduced into the fixed bed reactor at a molar ratio of 1:1, the reaction temperature was controlled at 150°C, the mixed gas reaction residence time was 20 seconds, the outlet gas was condensed and liquefied, and was distilled under normal pressure, and the fraction with a boiling point of 115-120°C was collected to obtain the fluoro ester (CF3)2CFCF2COOEt, the purity was 97%, and the yield was 81%. 1 H (CDCl3): 4.16(q, 2H), 1.24(t, 3H).

[0039] The supported catalyst used in the example mainly consisted of an active component and a carrier, wherein the mass ratio of the active component to the carrier was 1:50, the active component was cobalt fluoride, and the carrier was activated carbon. The preparation method of the supported catalyst referred to example 1.

[0040] Example 6

[0041] The difference between the example and example 1 was that the reaction temperature was 180°C, and the other conditions referred to example 1. The fluoro ester synthesized had a purity of 96% and a yield of 81%.

[0042] Example 7

[0043] A fixed bed reactor was charged with 200 g of the supported catalyst (the mass ratio of the olefinic ester to the active component of the supported catalyst was 1:0.4, and the composition and preparation of the supported catalyst were the same as in Example 1), the inside of the fixed bed reactor was replaced with high-purity nitrogen to ensure that the reaction was carried out in a nitrogen atmosphere, and the fluorine gas and the heated and vaporized olefinic ester (CF3CF2)(CCl3CF2)C=CFCOOCH3 were mixed with nitrogen at a volume ratio of 1:5 and introduced into the fixed bed reactor at a molar ratio of 1:1. The reaction temperature was controlled at 230°C, the residence time of the mixed gas was 20 seconds, the outlet gas was condensed and liquefied, and the distillate collected at 208-213°C under normal pressure was the fluoroester (CF3CF2)(CCl3CF2)CFCF2COOCH3, with a purity of 96% and a yield of 80%.

[0044] Example 8:

[0045] A fixed bed reactor was charged with 200 g of the supported catalyst (the mass ratio of the olefinic ester to the active component of the supported catalyst was 1:0.2, and the composition and preparation of the supported catalyst were the same as in Example 1), the inside of the fixed bed reactor was replaced with high-purity nitrogen to ensure that the reaction was carried out in a nitrogen atmosphere, and the fluorine gas and the heated and vaporized olefinic ester CF3CF=CFCOOCH3 were mixed with nitrogen at a volume ratio of 1:5 and introduced into the fixed bed reactor at a molar ratio of 1:1. The reaction temperature was controlled at 100°C, the residence time of the mixed gas was 20 seconds, the outlet gas was condensed and liquefied, and the distillate collected at 75-80°C under normal pressure was the fluoroester CF3CF2CF2COOCH3, with a purity of 98% and a yield of 83%.

[0046] Example 9:

[0047] A fixed bed reactor was charged with 200 g of the supported catalyst (the mass ratio of the olefinic ester to the active component of the supported catalyst was 1:0.2, and the composition and preparation of the supported catalyst were the same as in Example 1), the inside of the fixed bed reactor was replaced with high-purity nitrogen to ensure that the reaction was carried out in a nitrogen atmosphere, and the fluorine gas and the heated and vaporized olefinic ester CF3(CF2)5CF=CFCOOCH3 were mixed with nitrogen at a volume ratio of 1:5 and introduced into the fixed bed reactor at a molar ratio of 1:1. The reaction temperature was controlled at 180°C, the residence time of the mixed gas was 20 seconds, the outlet gas was condensed and liquefied, and the distillate collected at 140-145°C under normal pressure was the fluoroester CF3(CF2)5CF2CF2COOCH3, with a purity of 97% and a yield of 80%.

[0048] Example 10:

[0049] A 200 g supported catalyst (mass ratio of alkene to active component of the supported catalyst was 1:0.2, the composition and preparation of the supported catalyst were the same as in Example 1) was loaded into a fixed bed reactor, the internal gas of the fixed bed reactor was replaced with high-purity nitrogen to ensure that the reaction was carried out in a nitrogen atmosphere, and fluorine gas and alkene CF3CF2CF=CH2 after heating and vaporization were mixed with nitrogen at a volume ratio of 1:5, and then introduced into the fixed bed reactor at a molar ratio of 1:1. The reaction temperature was controlled at 170°C, the residence time of the mixed gas was 20 seconds, the outlet gas was condensed and liquefied, and then distilled under normal pressure. The fluoroester CF3CF2CF2CF2COOCH3 was collected in the 95-100°C fraction, with a purity of 95% and a yield of 82%.

Claims

1. A supported catalyst characterized in that, The supported catalyst mainly consists of an active component and a support, wherein the mass ratio of the active component to the support is 1:1 to 50, and the active component is one or more of nickel fluoride, chromium fluoride, and cobalt fluoride; the support is activated carbon. The supported catalyst is used for the continuous gas-phase catalytic synthesis of fluorinated esters from olefins and fluorine gas in a fixed bed.

2. The process for the preparation of supported catalyst according to claim 1, characterized in that, The active component is mixed with the carrier, granulated, sieved, heated at 70-150℃ for 5-15 hours, and then calcined at 300-500℃ for 5-15 hours to obtain the final product.

3. A process for the synthesis of fluorinated esters by fixed-bed continuous gas phase catalytic fluorination using the supported catalyst according to claim 1, characterized in that, Includes the following steps: Under a nitrogen atmosphere, the olefin ester is heated and vaporized, and then introduced into a fixed-bed reactor containing a supported catalyst along with fluorine gas. The catalytic fluorination reaction is carried out at a temperature of 50~400℃. After the reaction is completed, the gas is condensed, liquefied, and distilled to obtain the fluorinated ester.

4. The method of synthesizing fluorinated esters as claimed in claim 3, wherein, The molar ratio of olefin ester to fluorine gas introduced into the fixed-bed reactor is 1:0.5~2.

5. The method of synthesizing fluorinated esters as claimed in claim 3 wherein, The mass ratio of olefin ester to the active component of the supported catalyst is 1:0.02~0.

5.

6. The method for synthesizing fluorinated esters as described in claim 3, characterized in that, The residence time of the olefin ester and fluorine gas in the fixed-bed reactor is 3~30s.

7. The method for synthesizing fluorinated esters as described in claim 3, characterized in that, The ester structure is R1R2C=CR3C(O)OR4, and the general formulas of R1, R2, R3, and R4 are independently selected from CmH(2m+1-n)Xn, where m is a non-negative integer, n is an integer from 0 to 2m+1, and X is one of fluorine, chlorine, or bromine.