A method for preparing trifluoroethylamine by continuous aminolysis using a microchannel process

Abstract

The application discloses a method for preparing trifluoroethylamine by continuous aminolysis using a micro-channel method, which comprises the following steps: (1) mixing trifluoro-chloroethane with organic solvent I to obtain an A-phase solution; mixing ammonia, a surfactant and organic solvent II to obtain a B-phase solution; (2) feeding the A-phase solution and the B-phase solution into a micro-channel reactor at a certain flow rate at the same time, and heating to 50-110 DEG C to perform aminolysis reaction to obtain trifluoroethylamine. The preparation method disclosed by the application can ensure high conversion rate of a substrate, high selectivity and high yield of a target product, and the preparation process condition is simple, time consumption is short, and TFEA fine products are prepared, so that industrial production is more convenient to realize.

Description

Technical Field

[0001] This invention belongs to the technical field of fluorochemicals, specifically relating to a method for preparing trifluoroethylamine using a microchannel continuous ammonolysis method. Background Technology

[0002] Trifluoroethylamine (TFEA) is a colorless, transparent liquid with an ammonia-like odor. Its trifluoromethyl group endows it with significant chemical stability, strong electron-withdrawing properties, and lipophilicity, resulting in its unique physicochemical characteristics. TFEA is widely used in the fine chemical industry, including dyes, pesticides, and pharmaceuticals, and is an important fluorine-containing intermediate and raw material. In the dye industry, the addition of trifluoroethyl groups makes dye colors more vibrant and less prone to fading. In the pesticide industry, TFEA participates in the synthesis of pyrimidine, pyrazole, and pyrrole pesticides, helping to control invertebrate pests and address pesticide resistance issues. In the pharmaceutical industry, TFEA is a raw material for the synthesis of various drug intermediates and active pharmaceutical ingredients (APIs), used to treat cardiovascular diseases, mental illnesses, and immune disorders. In summary, TFEA, as a fluoride intermediate, has broad application value. Several synthetic methods have been reported in the literature, for example:

[0003] Patent GB717232 discloses a method using trifluoroacetamide as a raw material, in which it is dissolved in anhydrous diethyl ether or tetrahydrofuran, and lithium aluminum hydride is slowly added as a reducing agent to react and obtain 2,2,2-trifluoroethylamine hydrochloride, followed by the conversion of trifluoroethylamine hydrochloride to trifluoroethylamine. The advantages of this method are fewer reaction steps and the ability to reduce the amide to an amine under relatively mild conditions. However, the disadvantages include side reactions, a trifluoroethylamine yield of only 75.1%, and the high cost of trifluoroacetamide, which is not conducive to large-scale industrial production.

[0004] Patent CN109096121 discloses a method using trifluoroacetaldehyde as a raw material. The mixture is prepared by mixing trifluoroacetaldehyde with ammonia and then fed into a tubular reactor filled with a molecular sieve-supported catalyst. There, it undergoes a condensation-reduction reaction with ammonium formate, acting as a hydrogen donor, to obtain a product mixture containing an imine intermediate. After deammoniation and cooling, the mixture is transferred to a stirred tank and reacted under a nitrogen atmosphere and a secondary reducing agent. After the reaction, purified trifluoroacetaldehyde is obtained through vacuum distillation and rectification. The advantage of this method is its relatively mild reaction conditions. However, its disadvantages include a complex reaction process requiring two reductions to obtain the crude product. The presence of impurities such as the imine intermediate, ammonium formate, and the reducing agent further complicates the post-processing steps. Additionally, trifluoroacetaldehyde is extremely unstable, making raw material storage and transportation difficult and costly, thus hindering industrialization.

[0005] US Patent 4618718 discloses a method using trifluorochloroethane (R133a) as a raw material. This method employs a batch process, adding R133a, a solvent, and ammonia gas into a high-temperature, high-pressure reactor. The reaction temperature is 200-220°C, the pressure is 7-11 MPa, and the reaction time is 24 hours, yielding trifluoroethylamine (TFEA) with a yield of 86.8%. The advantages of this method are that the selected raw material R133a has an established production route, resulting in lower costs. Furthermore, due to current regulations on chlorofluorocarbons (CFCs), there is a need to develop downstream products for R133a; therefore, further converting R133a to TFEA via ammonolysis provides a potential application for R133a. However, the disadvantages of this method are the high reaction temperature and pressure, the demanding equipment requirements, and the significant safety risks and challenges associated with large-scale industrial production.

[0006] Patent CN201010525312 also discloses a method using R133a as a raw material. The method involves mixing liquid R133a dissolved in glycerol with ammonia solution of 30% wt-100% wt, where the molar ratio of ammonia to R133a is 8-15:1. The mixture is then introduced into a tubular reactor at a temperature of 150-200℃, a pressure of 2-4 MPa, and a time of 20-30 minutes. After obtaining the crude product, flash evaporation is performed to remove ammonia. Sodium carbonate is then added to the deammoniated liquid for neutralization, followed by vacuum distillation to obtain trifluoroethylamine with a yield of 95.6%. While this method significantly shortens the reaction time and improves the yield to some extent compared to patent US4618718, it uses a large amount of high-concentration ammonia solution, resulting in a significant excess of ammonia relative to R133a, which poses a greater environmental hazard and does not meet the requirements of green chemical production. Furthermore, the reaction temperature is not significantly improved.

[0007] From the perspective of cost and economic feasibility for industrial production, using R133a as a raw material for ammonolysis to prepare trifluoroethylamine (TFEA) is a more suitable option. Currently, most processes for preparing TFEA from R133a through ammonolysis involve high-temperature and high-pressure reaction conditions, long reaction times, and significant safety risks.

[0008] A microchannel reactor is a device that enables chemical reactions to occur at the microscale (typically micrometers or millimeters). It's a chemical reactor that uses multiple narrow channels (microchannels) to mix, heat, react, and separate reactants. Microchannel reactors have a large surface area, providing more reaction surface for the same reactor volume, thus increasing the reaction rate. Furthermore, the short distances within the microchannels accelerate mass transfer between reactants, preventing reactant stagnation. Simultaneously, microchannels have high thermal conductivity, resulting in excellent heat exchange between the reactor surface and the cooling system, allowing for more precise temperature control. Rapid heating or cooling of reactants within the microchannels prevents side reactions or incomplete reactions caused by excessively high or low temperatures.

[0009] Patent CN111138292A discloses a method for preparing TFEA using a microchannel method, and provides a detailed description of the microchannel specifications. The TFEA yield shown in its examples can reach 94%-95%. However, the reaction temperature mentioned in its examples ranges from a minimum of 110°C to a maximum of 190°C, which still requires a significant amount of energy. Furthermore, it does not clearly explain the reaction residence time and other reaction conditions. In addition, the solvent used in the conversion of R133a to TFEA is not clearly stated in the examples. Moreover, the molar ratio of R133a to NH3 mentioned in the patent is 3:1, which means that the maximum conversion rate of R133a in a single reaction can only reach 33.3%. Summary of the Invention

[0010] To address the aforementioned issues, this invention discloses a method for preparing trifluoroethylamine (TFEA) using continuous ammonolysis via microchannels. This method ensures high substrate conversion and high selectivity and yield of the target product. Furthermore, the preparation process is simple, time-efficient, and yields high-quality TFEA, making it easier to achieve industrial-scale production.

[0011] The specific technical solution is as follows:

[0012] A method for preparing trifluoroethylamine using a microchannel continuous ammonolysis method, comprising:

[0013] (1) Trifluorochloroethane was mixed with organic solvent I to obtain phase A solution; ammonia, surfactant and organic solvent II were mixed to obtain phase B solution;

[0014] (2) The A-phase solution and the B-phase solution are fed into the microchannel reactor at a certain flow rate and heated to 50-110℃ to carry out ammonolysis reaction to obtain trifluoroethylamine.

[0015] The preparation method disclosed in this invention uses a microchannel reactor with R133a as the substrate and ammonia as the ammonia source. R133a reacts with NH3 in the liquid phase, where the choice of solvent is significantly influenced by the difference in hydrophilicity and hydrophobicity between R133a and NH3. NH3 is extremely hydrophilic, while R133a is extremely hydrophobic. Therefore, it is essential to select an excellent reaction solvent system that facilitates the formation of a homogeneous phase between R133a and NH3. Besides a suitable reaction solvent, the selection of surfactant is also crucial. In this invention, surfactants can promote bubble formation and gas dissolution, increasing the contact area between R133a and ammonia and the reaction solvent, thereby accelerating the reaction rate. Furthermore, when reactants are difficult to mix, surfactants can promote uniform dispersion of reactants by reducing interfacial tension. Simultaneously, the hydrophilic and lipophilic properties of surfactants can affect the solubility of reactants, thereby altering their activity. During mass transfer between the solvent and reactants, surfactants can increase the solubility of reactants in the solvent or change the properties of the solvent, making the reactants more readily participate in the reaction.

[0016] In step (1):

[0017] Preferred:

[0018] The organic solvent I is selected from one or more of N-methylpyrrolidone, N,N-dimethylformamide, dimethyl sulfoxide, propylene glycol, ethylene glycol, glycerol, 1,4-dioxane, N,N-dimethylacetamide, and toluene;

[0019] The organic solvent II is selected from one or more of N-methylpyrrolidone, N,N-dimethylformamide, dimethyl sulfoxide, propylene glycol, ethylene glycol, glycerol, 1,4-dioxane, N,N-dimethylacetamide, and toluene;

[0020] To simplify production, organic solvent I and organic solvent II are selected from the same type.

[0021] Further optimization,

[0022] The organic solvent I is selected from one or more of N-methylpyrrolidone, N,N-dimethylformamide, and ethylene glycol;

[0023] The organic solvent II is selected from one or more of N-methylpyrrolidone, N,N-dimethylformamide, and ethylene glycol.

[0024] Preferred:

[0025] The surfactant is selected from one or more of the following: hexadecyltrimethylammonium bromide, polyvinyl alcohol, polyethylene glycol, sodium octylphenoxyacetate, sodium tetradecyl sulfate, octadecyltrimethylammonium chloride, polysorbate 80, trioctylmethylammonium chloride, polydimethylsiloxane, hexadecylammonium chloride, polyvinylpyrrolidone, and dodecyl disulfonate.

[0026] More preferably, the surfactant is selected from hexadecyltrimethylammonium bromide and / or hexadecanoic acid aminopropyltrimethylammonium chloride.

[0027] Experiments have shown that the above-mentioned organic solvents and the reaction system composed of organic solvents and surfactants can promote the reactivity of R133a and ammonia, ensuring high conversion of the substrate and high selectivity and high yield of the target product.

[0028] In step (1):

[0029] Preferred:

[0030] In the A-phase solution, the mass ratio of trifluorochloroethane to organic solvent I is 1:(1-16); specifically, it can be 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16 or any ratio within the above range;

[0031] Further preferably, the mass ratio of the two is 1:(1-12); more preferably, it is 1:(2-12).

[0032] Preferred:

[0033] When preparing the A-phase solution, an inert gas is used for pressurization protection.

[0034] Preferred:

[0035] In the B-phase solution, the mass ratio of ammonia to organic solvent II is 1:(3-10), specifically 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10 or any ratio within the above range;

[0036] Further preferably, in phase B solution, the mass ratio of ammonia to organic solvent II is 1:(3-5); more preferably, it is 1:5.

[0037] Preferred:

[0038] In the B-phase solution, the mass ratio of surfactant to ammonia is (0.01-10):100, specifically 0.01:100, 0.05:100, 0.1:100, 0.5:100, 1:100, 2:100, 3:100, 4:100, 5:100, 6:100, 7:100, 8:100, 9:100, 10:100, or any ratio within the above range;

[0039] Further preferably, in phase B solution, the mass ratio of surfactant to ammonia is (0.05-7):100; more preferably (2-5):100; and even more preferably (3.5-5):100.

[0040] Preferred:

[0041] When preparing the B-phase solution, an inert gas is used for pressurization protection.

[0042] In step (2):

[0043] Preferred:

[0044] The flow rate of the A phase solution is 1 to 4 mL / min; specifically, it can be 1 mL / min, 1.5 mL / min, 2 mL / min, 2.5 mL / min, 3 mL / min, 3.5 mL / min, 4 mL / min or any value within the above range; more preferably, the flow rate of the A phase solution is 1 to 3 mL / min.

[0045] Preferred:

[0046] The flow rate of the B phase solution is 1 to 8 mL / min; specifically, it can be 1 mL / min, 1.5 mL / min, 2 mL / min, 2.5 mL / min, 3 mL / min, 3.5 mL / min, 4 mL / min, 4.5 mL / min, 5 mL / min, 5.5 mL / min, 6 mL / min or any value within the above range; more preferably, the flow rate of the B phase solution is 1 to 6 mL / min.

[0047] Preferred:

[0048] The flow rate ratio of phase A solution to phase B solution is 1:(0.3~3.0); specifically, it can be 1:0.3, 1:0.5, 1:0.8, 1:1, 1:1.5, 1:2, 1:2.5, 1:3 or any ratio within the above range;

[0049] Further optimization is that the flow rate ratio of phase A solution to phase B solution is 1:(1~2).

[0050] Preferred:

[0051] The total flow rate of the A-phase solution and the B-phase solution is controlled between 1 and 12 mL / min; specifically, it can be 1 mL / min, 2 mL / min, 3 mL / min, 4 mL / min, 5 mL / min, 6 mL / min, 7 mL / min, 8 mL / min, 9 mL / min, 10 mL / min, 11 mL / min, 12 mL / min or any value within the above range.

[0052] Experiments have shown that by continuously optimizing the above-mentioned raw material composition, flow rate and other parameters, the reactivity of R133a and ammonia can be promoted, ensuring high substrate conversion rate and high selectivity and high yield of target product.

[0053] Preferred:

[0054] In step (2), the microchannel reactor contains 5 to 10 interconnected microreactors with identical structures; specifically, there may be 5, 6, 7, 8, 9, or 10 such microreactors.

[0055] Further optimization involves connecting 8 to 10 microreactors in series.

[0056] Preferred:

[0057] In step (2), the temperature of the ammonolysis reaction is 80 to 110°C; specifically, it can be 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C or any value within the above range.

[0058] A further preferred temperature is 80°C.

[0059] Since the reaction system used in this invention exhibits excellent solubility for both raw materials R133a and NH3, as well as the product TFEA, this also means that the separation of the product after the reaction will be more difficult. Based on this, this method further proposes a distillation process suitable for preparing crude TFEA and then obtaining refined TFEA from this reaction system.

[0060] Preferably, in step (2), the reaction solution obtained after the ammonolysis reaction is subjected to two-stage distillation, including:

[0061] First-stage distillation: The reaction liquid is fed into the bottom of the distillation column to begin the first-stage distillation. When the bottom of the column is heated from room temperature to 50-60°C, it begins to boil and discharge the NH3 component. The temperature is continued to rise to 100°C, and after the reflux stabilizes, the product is collected. After there is no reflux liquid at this temperature, the temperature is raised by 10-20°C in full reflux mode. After the system stabilizes, the product is collected at a reflux ratio of 1:1 until the boiling point of the reaction liquid is reached and no reflux condensate is distilled out.

[0062] Second-stage distillation: The product from the first-stage distillation is fed into the bottom of the distillation column to begin the second-stage distillation. The initial temperature of the bottom is set at 20°C, and then slowly increased to 45°C. Total reflux is used in the initial stage of the second-stage distillation, while the condensation temperature is controlled at -20 to -10°C. The product is tested, and mining begins when the purity of TFEA is not less than 99%.

[0063] Compared with the prior art, the present invention has the following advantages:

[0064] This invention discloses a method for preparing trifluoroethylamine by continuous ammonolysis using a microchannel method, with R133a as the raw material and ammonia as the ammonia source. Due to the large difference in hydrophilicity and hydrophobicity between the two, the reaction conditions are quite demanding. This invention proposes a microchannel, a preferred solvent, and a surfactant strategy to solve these problems.

[0065] Meanwhile, since the reaction system mentioned in this invention exhibits excellent solubility for both raw materials R133a and NH3 and product TFEA, this also means that the difficulty of product separation after the reaction will increase. Based on this, this invention also proposes a two-stage distillation process suitable for preparing crude TFEA and then obtaining refined TFEA from this reaction system.

[0066] The preparation method disclosed in this invention shortens the reaction time, increases spacetime yield, reduces energy consumption, achieves a substrate conversion rate of up to 99.8%, a product yield of up to 98.5%, and a purity of up to 99.5%. Attached Figure Description

[0067] Figure 1 The above is a gas phase diagram of the raw material obtained by mixing phase A solution and phase B solution in Example 1.

[0068] Figure 2 This is a gas phase diagram of the product from the reaction solution prepared in Example 1;

[0069] Figure 3 for Figure 1 Fragment mass spectrum of the substance with the peak at 5.5 min;

[0070] Figure 4 for Figure 2 Fragment mass spectrum of the substance with the peak at 4.6 min. Detailed Implementation

[0071] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0072] In the description of this invention, it should be noted that those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances. The embodiments of this invention are described below based on its overall structure. Unless otherwise specified, the raw materials used in the embodiments of this invention were all purchased commercially.

[0073] Example 1

[0074] (1) Weigh 600g of N-methylpyrrolidone, evacuate the vacuum, connect the R133a cylinder to the LPG cylinder 1, open the valve, and introduce 300g of R133a at room temperature to prepare phase A solution. Connect the nitrogen cylinder to the LPG cylinder 1 and maintain a certain nitrogen pressure. Weigh 600g of N-methylpyrrolidone (unless otherwise specified, organic solvent I and organic solvent II in this invention are of the same type) and add it to the LPG cylinder 2. Add 4.2g of hexadecyltrimethylammonium bromide to the LPG cylinder 2 according to a mass ratio of 3.5wt%. Evacuate the vacuum, connect the NH3 cylinder to the LPG cylinder 2, open the valve, and introduce 120g of NH3 at room temperature to prepare phase B solution. Connect the nitrogen cylinder to the LPG cylinder 2 and maintain a certain nitrogen pressure.

[0075] (2) Start the feed of the 316L microchannel reactor, connect the plunger pump 1 to the liquefied gas cylinder 1, control the flow rate of the A phase solution to 3mL / min, connect the plunger pump 2 to the liquefied gas cylinder 2, control the flow rate of the B phase solution to 3mL / min (after conversion, the molar ratio of R133a to ammonia is 1:3), use 10 microreactors as the device, control the reaction temperature at 80℃, and the residence time at 15min.

[0076] (3) The reaction liquid is collected and subjected to two-stage distillation using a φ3×50cm distillation column packed with 316L stainless steel in a triangular spiral configuration. The theoretical number of trays is 50-70 / meter (i.e., approximately 25-35 trays in the apparatus). The distillation column is insulated with a vacuum jacket; the connection between the distillation head and the distillation column is insulated with insulating tape; the top condenser uses two condenser tubes connected in series, with the condensate inlet temperature at -20℃. To ensure the condensation of low-boiling components, copper tubing is wrapped around the bottom of the condenser, the U-tube, and the receiver section of the distillation apparatus, and low-temperature circulating liquid is used for cooling. Simultaneously, a gas washing bottle containing NMP is connected to the outlet of the non-condenser to collect non-condensable low-boiling components: NH3 and R133a.

[0077] First-stage distillation: Weigh 850g of the reaction solution into a 1000mL distillation flask and place it in the reboiler. Check the airtightness and begin distillation. Slowly heat the reboiler from room temperature. When the reboiler temperature reaches approximately 50-60℃, boiling begins and the NH3 component is discharged. When the reboiler temperature rises to 100℃ and the reflux stabilizes, begin collecting the distillate at a 1:1 reflux ratio. Once there is no reflux liquid at this temperature, increase the temperature by 20℃ in total reflux mode. After the system stabilizes, collect the distillate again at a 1:1 reflux ratio until the boiling point of the reaction solution is reached and no reflux condensate is distilled out.

[0078] Second-stage distillation: The initial temperature of the reboiler was set at 20℃, and slowly increased to 45℃. Total reflux was used in the initial stage of the second-stage distillation, while the condenser temperature was controlled between -20℃ and -10℃. The solution in the U-tube was monitored, and extraction was carried out after the TFEA purity met the requirements. TFEA with a purity of 99.7% was obtained. Testing showed that the R133a conversion rate was 99.8%, and the TFEA yield was 97.7%.

[0079] Figure 1 This is a gas phase diagram of the raw material obtained by mixing phase A solution and phase B solution in this embodiment;

[0080] Figure 2 This is a gas phase diagram of the product of the reaction solution prepared in this embodiment; Figure 3 for Figure 1 Fragment mass spectra of the substance with the peak at 5.5 min (top image is the detection spectrum, bottom image is the standard spectrum); Figure 4 for Figure 2 The fragment mass spectrum of the substance with the peak at 4.6 min is shown (top image is the detection spectrum, bottom image is the standard spectrum). Combining the four images confirms that this method can convert R133a into TFEA.

[0081] Examples 2-9

[0082] The preparation process is basically the same as in Example 1, except that the types of organic solvents used in preparing phase A and phase B solutions are different. The specific types of solvents used and the conversion rates of R133a and TFEA yields in each example are listed in Table 1 below.

[0083] Table 1

[0084]

[0085] Examples 10-20

[0086] The preparation process is basically the same as in Example 1, except that the type of surfactant used in preparing the B phase solution is different. The specific types used and the R133a conversion rate and TFEA yield data in each example are listed in Table 2 below.

[0087] Table 2

[0088]

[0089] Examples 21-24

[0090] The preparation process is basically the same as in Example 1, except that the mass of R133a added when preparing the A-phase solution is different. The specific mass, the adjusted mass ratio to organic solvent I, and the R133a conversion rate and TFEA yield data in each example are listed in Table 3 below.

[0091] Table 3

[0092]

[0093] a: After conversion, the molar ratio of R133a to ammonia in Example 21 is 1:2.

[0094] Examples 25-27

[0095] The preparation process is basically the same as in Example 1, except that the mass of the surfactant used in preparing the B phase solution is different. The specific mass, the adjusted mass ratio to ammonia, and the R133a conversion rate and TFEA yield data in each example are listed in Table 4 below.

[0096] Table 4

[0097]

[0098] Examples 28-29

[0099] The preparation process is basically the same as in Example 1, except that the mass of ammonia gas used in preparing the B phase solution is different. The specific mass, the adjusted mass ratio of ammonia gas to organic solvent II, and the R133a conversion rate and TFEA yield data in each example are listed in Table 5 below.

[0100] Table 5

[0101]

[0102] Examples 30-35

[0103] The preparation process is basically the same as in Example 1, except that the flow rates and / or ratios of phase A and phase B solutions are different. Specific ratios and the R133a conversion and TFEA yield data for each example are listed in Table 6 below.

[0104] Table 6

[0105]

[0106] b: After conversion, the molar ratio of R133a to ammonia in Example 30 is 1:1;

[0107] c: After conversion, the molar ratio of R133a to ammonia in Example 31 is 1:2.

[0108] Examples 36-37

[0109] The preparation process is basically the same as in Example 1, except for the selection of the number of microchannel reactor blocks. The specific number of blocks and the R133a conversion and TFEA yield data in each example are listed in Table 7 below.

[0110] Table 7

[0111]

[0112] Examples 38-39

[0113] The preparation process is basically the same as in Example 1, except for the reaction temperature. The specific temperatures and the R133a conversion and TFEA yield data in each example are listed in Table 8 below.

[0114] Table 8

[0115]

[0116] Comparative Example 1

[0117] The preparation process is basically the same as in Example 1, except that the organic solvent used in preparing phase A and phase B solutions is pyridine (with the same mass as in Example 1).

[0118] The test results showed that in this comparative example, the conversion rate of R133a was 54.2%, and the yield of TFEA was 43.7%.

[0119] Comparative Example 2

[0120] The preparation process is basically the same as in Example 1, except that the surfactant is replaced with an equal mass of sodium dodecyl sulfate when preparing the B phase solution.

[0121] The test results showed that in this comparative example, the conversion rate of R133a was 49.7%, and the yield of TFEA was 35.8%.

[0122] Comparative Example 3

[0123] The preparation process is basically the same as in Example 1, except that the reaction temperature is replaced with 150°C.

[0124] Tests showed that in this comparative example, the conversion rate of R133a was 99.9%, and the yield of TFEA was 55.6%.

[0125] Comparative Example 4

[0126] The preparation process is basically the same as in Example 1, except that the reaction temperature is replaced with 30°C.

[0127] The test results showed that in this comparative example, the conversion rate of R133a was 5.4%, and the yield of TFEA was 3.9%.

[0128] The above-described embodiments are preferred embodiments, but the scope of protection of the present invention is not limited thereto. Those skilled in the art can easily understand the spirit of the present invention based on the above embodiments and make different extensions and variations, but as long as they do not depart from the spirit of the present invention, they are all within the scope of protection of the present invention.

Claims

1. A process for the continuous aminolysis preparation of trifluoroethylamine using the microchannel process, characterized in that, The method comprises the following steps: (1) mixing trifluoro-chloroethane and an organic solvent I to obtain a phase A solution; mixing ammonia, a surfactant and an organic solvent II to obtain a phase B solution; the organic solvent I is selected from one or more of N-methyl pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide and ethylene glycol; the organic solvent II is selected from one or more of N-methyl pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide and ethylene glycol; the surfactant is selected from cetyl trimethyl ammonium bromide and / or palmitamide propyl trimethyl ammonium chloride; in the phase A solution, the mass ratio of trifluoro-chloroethane to the organic solvent I is 1: (2-12); in the phase B solution, the mass ratio of ammonia to the organic solvent II is 1:5, and the mass ratio of the surfactant to ammonia is (3.5-5):100; (2) feeding the phase A solution and the phase B solution into a micro-channel reactor at a certain flow rate, and heating to 80-110°C to perform an ammonolysis reaction to obtain trifluoroethylamine; the flow rate of the phase A solution is 1-3 mL / min; the flow rate of the phase B solution is 1-6 mL / min; the flow rate ratio of the phase A solution to the phase B solution is 1: (1-2); the micro-channel reactor is provided with 8-10 micro-reactors with the same structure connected in series; the reaction liquid obtained after the ammonolysis reaction is subjected to two-stage rectification, comprising: I-stage rectification: the reaction liquid is fed into a rectification column to start I-stage rectification, the column is heated from room temperature to 50-60°C to start boiling to discharge NH3 components; the temperature is continuously increased to 100°C, and after the reflux is stable, the product is collected; after the temperature without reflux liquid, the system is stable, and then the reflux ratio is 1:1, until the boiling point of the reaction liquid is reached without reflux condensate. II-stage rectification: the collected liquid of I-stage rectification is fed into a rectification column to start II-stage rectification, the initial temperature of the column is set to 20°C, and the temperature is slowly increased to 45°C; at the initial stage of II-stage rectification, full reflux is used, and the condensation temperature is controlled at -20 to -10°C; the product is detected, and when the purity of TFEA is not less than 99%, the product is collected.

2. The process for the continuous aminolysis preparation of trifluoroethylamine using the microchannel process according to claim 1, characterized in that, In step (1): when the phase A solution is prepared, inert gas is used for pressurization protection; when the phase B solution is prepared, inert gas is used for pressurization protection.

3. The method for continuously preparing trifluoroethylamine by ammonolysis according to claim 1, wherein the total flow rate of the phase A solution and the phase B solution is controlled at 1-12 mL / min. ​

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