A method for purifying 2,4,6-triaminotoluene

Abstract

The present application relates to the field of chemical engineering and material technology, and provides a method for purifying 2,4,6-triaminotoluene, including: in an oxygen-free atmosphere, a specific hydrated organic solvent is added to the first container to dissolve the crude 2,4,6-triaminotoluene at a target dissolution temperature, then transferred to the second container, and the second container is cooled to the target cooling temperature, and the crystallized product is separated out and then passed through a decolorizing filter membrane and dried to obtain a final product. The method provided by the present application, in the purification process, is protected by an inert gas atmosphere throughout the entire process, and 2,4,6-triaminotoluene is prevented from deteriorating due to oxidation during the purification process; the target dissolution temperature and target cooling temperature set by the present application are determined based on the solubility of a specific hydrated organic solvent dissolving 2,4,6-triaminotoluene at different temperatures, and the yield and purity of 2,4,6-triaminotoluene are improved. The method is simple to operate, the solvent is cheap, green and safe, and the purification efficiency is high, which is conducive to industrial promotion.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of chemical engineering and material technology, and specifically, to a method for purifying 2,4,6-triaminotoluene. Background Art

[0002] 2,4,6-Triaminotoluene (TAT for short), as a trifunctional aromatic polyamine, has great application potential. It can be used as a precursor raw material for many high value-added chemical products, such as the synthesis of new adhesives such as toluene triisocyanate and insensitive explosives such as 1,3,5-triamino-2,4,6-trinitrobenzene (TATB). It can also be used in the construction of new porous polymer materials.

[0003] The pure TAT sample is white to light yellow crystals with a melting point of 117°C and an initial decomposition temperature of about 192°C. However, 2,4,6-triaminotoluene (TAT for short) is usually obtained by hydrogenation of trinitrotoluene, so it is mixed with the by-product water; on the other hand, due to its high reactivity and easy oxidation, it is usually a dark-colored product. In order to obtain a high-purity TAT product, the crude TAT needs to be purified. However, since TAT is a new chemical product, its purification process has not been reported. Therefore, for the purification of TAT, the art urgently needs a simple, efficient, low-pollution and low-cost purification method. Summary of the invention

[0004] The embodiment of the present application provides a method for purifying 2,4,6-triaminotoluene, aiming to solve the problem of the lack of a method for purifying 2,4,6-triaminotoluene and provide a simple, efficient, low-pollution and low-cost method for purifying 2,4,6-triaminotoluene.

[0005] The present application embodiment provides a method for purifying 2,4,6-triaminotoluene, comprising:

[0006] Adding a solvent and a crude product of 2,4,6-triaminotoluene in a preset mass ratio into a first container to obtain a crude product mixture; performing a deoxygenation operation on the first container and the second container, and replacing the first container and the second container with an inert gas atmosphere;

[0007] The temperature of the crude mixture in the first container is raised to the target dissolution temperature, and the mixture is slowly stirred; the crude mixture is passed through a decolorizing filter membrane to obtain a crude filtrate, and the decolorizing filter membrane is used to filter and decolorize the crude mixture; the crude filtrate is transferred to the second container, cooled to the target cooling temperature, and slowly stirred to precipitate a crystalline product;

[0008] The crystal product is obtained by filtering, and the crystal product is dried to obtain a final product, wherein the final product is 2,4,6-triaminotoluene, the yield of the final product is greater than 80%, and the purity of the final product is greater than 99.0%.

[0009] Optionally, the method includes at least one of the following features:

[0010] (1) The first container and the second container are fully enclosed reactors with jackets;

[0011] (2) The preset mass ratio of the crude 2,4,6-triaminotoluene to the solvent is (1:10) to (1:150);

[0012] (3) The solvent is a mixed solution of an organic solvent and water, the organic solvent is at least one of toluene, acetone, dioxane, ethyl acetate, ethanol, acetonitrile, methanol, and N,N-dimethylformamide, and the mass ratio of the organic solvent to water is (100:1) to (5:1);

[0013] (4) The inert gas is nitrogen or argon.

[0014] Optionally, the first container and the second container are subjected to a deoxygenation operation, and the specific steps are as follows:

[0015] Passing high-pressure inert gas into the first container and the second container so that the pressures in the first container and the second container are both within a preset pressure range;

[0016] Performing stirring for a first stirring time in the first container and the second container, and then releasing the pressure in the first container and the second container to normal pressure;

[0017] Repeat the above steps of passing high-pressure inert gas, stirring, and depressurizing to normal pressure for a first preset number of times.

[0018] Optionally, the first container and the second container are replaced with an inert gas atmosphere, and the specific steps are as follows:

[0019] Passing high-pressure inert gas into the first container and the second container so that the pressures in the first container and the second container are within the preset pressure range;

[0020] Performing stirring for the first stirring time in the first container and the second container, and then releasing the pressure in the first container and the second container to normal pressure;

[0021] Repeat the above-mentioned steps of passing high-pressure inert gas, stirring, and decompressing to normal pressure for the first preset number of times.

[0022] Optionally, the temperature of the crude mixture in the first container is raised to a target dissolution temperature, and slowly stirred; the crude mixture is passed through a decolorizing filter membrane to obtain a crude filtrate, and the decolorizing filter membrane is used to filter and decolorize the crude mixture; the crude filtrate is transferred to the second container, cooled to a target cooling temperature, and slowly stirred to precipitate a crystalline product. The specific steps are as follows:

[0023] Raising the temperature of the crude mixture in the first container to the target dissolution temperature;

[0024] During the second stirring time, stirring the crude mixture at a preset stirring rate;

[0025] Passing the crude mixture through a decolorizing filter membrane while it is hot, performing rapid filtration and decolorization, to obtain the crude filtrate;

[0026] transferring the crude product filtrate into the second container, and cooling the second container to the target cooling temperature;

[0027] During the third stirring time, the crude filtrate is stirred at the preset stirring rate to precipitate the crystalline product.

[0028] Optionally, filtering to obtain the crystallized product, and drying the crystallized product to obtain a final product, comprising:

[0029] Passing the crude product filtrate through a decolorizing filter membrane through a positive pressure filter to obtain the crystalline product;

[0030] The crystallized product is sent to a vacuum dryer and dried at a drying temperature and a drying pressure to obtain the final product.

[0031] Optionally, the method includes at least one of the following features:

[0032] (1) The preset pressure range is 0.4-1.0 MPa;

[0033] (2) The first stirring time is 10 min;

[0034] (3) The first preset number of times is 3 times.

[0035] Optionally, the method includes at least one of the following features:

[0036] (1) The target dissolution temperature is 80-90°C;

[0037] (2) The second stirring time is 30-45 min;

[0038] (3) The preset stirring rate is 30 rpm;

[0039] (4) The target cooling temperature is 0-20°C;

[0040] (5) The third stirring time is 45-60 min.

[0041] Optionally, the method includes at least one of the following features:

[0042] (1) The drying temperature is 40-60°C;

[0043] (2) The drying pressure is below -0.01 MPa.

[0044] Beneficial effects:

[0045] The present application provides a method for purifying 2,4,6-triaminotoluene, wherein a specific hydrated organic solvent is added to a first container in an oxygen-free atmosphere to dissolve a crude 2,4,6-triaminotoluene at a target dissolution temperature, the crude 2,4,6-triaminotoluene is filtered and decolorized while hot through a decolorizing filter membrane, and then the crude 2,4,6-triaminotoluene is transferred to a second container, and then the second container is cooled to a target cooling temperature, and a crystal product is filtered and dried after precipitation to obtain a final product, which has the following effects:

[0046] (1) In the purification process of the present application, an inert gas atmosphere is used for protection throughout the entire process, thereby preventing 2,4,6-triaminotoluene from deteriorating due to oxidation during the purification process.

[0047] (2) The target dissolution temperature and target cooling temperature of the present application are determined based on the solubility of a specific hydrated organic solvent in dissolving 2,4,6-triaminotoluene at different temperatures, thereby improving the yield and purity of 2,4,6-triaminotoluene.

[0048] (3) The method provided in this application is simple to operate, has low solvent price, is green and safe, has high purification efficiency, and is conducive to industrial promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0050] Figure 1 This is a flow chart of a method for purifying 2,4,6-triaminotoluene proposed in an embodiment of the present application;

[0051] Figure 2 is the nuclear magnetic resonance hydrogen spectrum of the final product of Example 1 of the present application;

[0052] Figure 3This is the carbon nuclear magnetic resonance spectrum of the final product of Example 1 of the present application;

[0053] Figure 4 This is the infrared spectrum of the final product of Example 1 of the present application;

[0054] Figure 5 This is a high-resolution mass spectrum of the final product of Example 1 of the present application;

[0055] Figure 6 This is a high performance liquid chromatogram of the final product of Example 1 of the present application;

[0056] Figure 7 This is a high performance liquid chromatogram of the final product of Example 2 of the present application;

[0057] Figure 8 This is a high performance liquid chromatogram of the final product of Example 3 of the present application. DETAILED DESCRIPTION

[0058] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0059] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the prior art can be used. The reagents and other instruments used without specifying the manufacturer are all conventional reagent products that can be purchased commercially.

[0060] Since 2,4,6-triaminotoluene (TAT for short) is usually obtained by hydrogenation of trinitrotoluene, it is mixed with the by-product water; on the other hand, due to its high reactivity and easy oxidation, it is usually a dark-colored product. In order to obtain a high-purity TAT product, the crude TAT needs to be purified. However, TAT is a new chemical product, and its purification process has not been reported in the relevant technology. Therefore, for the purification of TAT, the art urgently needs a simple, efficient, low-pollution and low-cost purification method.

[0061] In view of this, the present invention provides a method for purifying 2,4,6-triaminotoluene. Figure 1 A flow chart of a purification method of 2,4,6-triaminotoluene is shown, such as Figure 1 As shown, the specific steps of the purification method of 2,4,6-triaminotoluene are as follows:

[0062] S101. Add a solvent and a crude 2,4,6-triaminotoluene into a first container according to a preset mass ratio, and perform deoxygenation and atmosphere replacement.

[0063] In a specific implementation, a solvent and a crude 2,4,6-triaminotoluene are added to a first container according to a preset mass ratio, wherein the solvent is a specific hydrated organic solvent determined based on the solubility of 2,4,6-triaminotoluene in the solvent. The first container and the second container are deoxygenated, and the first container and the second container are replaced with an inert gas atmosphere.

[0064] In some embodiments, the first container and the second container are fully enclosed reactors with jackets.

[0065] In some embodiments, the preset mass ratio of the crude 2,4,6-triaminotoluene to the solvent is (1:10) to (1:150).

[0066] In some embodiments, the solvent is a mixed solution of an organic solvent and water, the organic solvent is at least one of toluene, acetone, dioxane, ethyl acetate, ethanol, methanol, and N,N-dimethylformamide, and the mass ratio of the organic solvent to water is (100:1) to (5:1).

[0067] In some embodiments, the inert gas is nitrogen or argon.

[0068] Among them, the deoxygenation operation is specifically to pass high-pressure inert gas into the first container and the second container so that the pressures in the first container and the second container are both within a preset pressure range; stir the first container and the second container for a first stirring time, and then reduce the pressure in the first container and the second container to normal pressure; repeat the above high-pressure inert gas, stirring, and pressure reduction to normal pressure operations for a first preset number of times.

[0069] The atmosphere replacement is specifically as follows: passing a high-pressure inert gas into the first container and the second container so that the pressures in the first container and the second container are both within the preset pressure range; stirring the first container and the second container for the first stirring time, and then reducing the pressure in the first container and the second container to normal pressure; repeating the above-mentioned high-pressure inert gas passing, stirring, and reducing the pressure to normal pressure operations for the first preset number of times.

[0070] In some embodiments, the preset pressure range is 0.4-1.0 MPa.

[0071] In some embodiments, the first stirring time is 10 min.

[0072] In some implementations, the first preset number of times is 3 times.

[0073] Since in the prior art, 2,4,6-triaminotoluene (TAT for short) is usually obtained by hydrogenation of trinitrotoluene, and therefore mixed with byproduct water, the ratio of a specific hydrated organic solvent to water is controlled in the embodiment of the present application, so that when a specific hydrated organic solvent dissolves a crude 2,4,6-triaminotoluene, it will not separate with water while ensuring that the 2,4,6-triaminotoluene in the crude 2,4,6-triaminotoluene has a large solubility in the solvent. At the same time, since 2,4,6-triaminotoluene is highly reactive and easily oxidized and deteriorated, a fully enclosed reactor is selected as the first container and the second container, and oxygen in the first container and the second container is removed by a deoxygenation operation, and an inert gas atmosphere is used for atmosphere replacement to ensure that the entire purification process is carried out in an inert gas atmosphere, thereby preventing the purified 2,4,6-triaminotoluene from being oxidized and deteriorated.

[0074] S102, heating the first container to the target dissolution temperature while slowly stirring, and passing the mixture through a decolorizing filter membrane while hot to obtain a crude filtrate.

[0075] In a specific implementation, the temperature of the crude mixture in the first container is raised to the target dissolution temperature; within a second stirring time, the crude mixture is stirred at a preset stirring rate;

[0076] The crude mixture is filtered and decolorized while hot using a decolorizing filter membrane to filter out insoluble impurities in the mixture to obtain a crude filtrate, wherein the target dissolution temperature is determined based on the solubility of the specific hydrated organic solvent in dissolving 2,4,6-triaminotoluene at different temperatures. At the target dissolution temperature, the solvent has a large solubility for 2,4,6-triaminotoluene, and 2,4,6-triaminotoluene can be fully dissolved within the second stirring time.

[0077] In some embodiments, the target dissolution temperature is 80-90°C.

[0078] In some embodiments, the second stirring time is 30-45 min.

[0079] In some embodiments, the preset stirring rate is 30 rpm.

[0080] S103, transferring the crude filtrate into a second container, cooling the second container to a target cooling temperature, and slowly stirring the second container to precipitate a crystalline product.

[0081] In a specific implementation, the second container is cooled to the target cooling temperature; within a third stirring time, the crude filtrate is stirred at the preset stirring rate to precipitate the crystalline product.

[0082] In some embodiments, the target cooling temperature is 0-20°C;

[0083] In some embodiments, the third stirring time is 45-60 min.

[0084] Based on the understanding of the physical and chemical properties of 2,4,6-triaminotoluene, the crystallization product is obtained by cleverly utilizing the temperature difference and time difference and the crystallization kinetics. Through the difference in the solubility of 2,4,6-triaminotoluene at different temperatures of the selected solvent, when cooling from the target dissolution temperature to the target cooling temperature under the preset stirring time, 2,4,6-triaminotoluene precipitates 2,4,6-triaminotoluene crystals from the supersaturated state.

[0085] S104, filtering to obtain a crystalline product, and drying the crystalline product to obtain a final product.

[0086] The crude product filtrate is filtered through a positive pressure filter (decolorizing filter membrane) to obtain the crystalline product; the crystalline product is sent to a vacuum dryer and dried at a drying temperature and a drying pressure to obtain the final product.

[0087] In some embodiments, the drying temperature is 40-60°C;

[0088] In some embodiments, the drying pressure is -0.01 MPa or less.

[0089] The final product is 2,4,6-triaminotoluene, the yield of the final product (based on crude 2,4,6-triaminotoluene) is greater than 80%, and the purity of the final product is greater than 99.0%.

[0090] In order to enable those skilled in the art to understand the present application more clearly, the method for extracting high-purity trinitrotoluene from retired ammunition described in the present application is now described in detail through the following examples.

[0091] Embodiment 1

[0092] S101. Add a solvent and a crude 2,4,6-triaminotoluene into a first container according to a preset mass ratio, and perform deoxygenation and atmosphere replacement.

[0093] During the specific implementation, the first container and the second container are fully enclosed reactors with jackets. 1kg of toluene and 0.1kg of water are added to the first container as solvents (the mass ratio of toluene to water is 10:1), and 5g of crude 2,4,6-triaminotoluene is quickly added to the solvent in the reactor to obtain a crude mixture. High-pressure nitrogen is connected to the reactor (the first container and the second container) to make the pressure in the reactor reach 0.4MPa, continue to stir for 10 minutes, and then unload to normal pressure. Repeat 3 times, and the deoxygenation operation of the reactor is considered to be completed. High-pressure nitrogen is connected to the reactor again to make the pressure in the reactor reach 0.4MPa, continue to stir for 10 minutes, and then unload to normal pressure. Repeat 3 times, and the atmosphere replacement of nitrogen is considered to be completed.

[0094] S102, heating the first container to the target dissolution temperature while slowly stirring, and passing the mixture through a decolorizing filter membrane while hot to obtain a crude filtrate.

[0095] The reactor was heated to 90°C and stirred at a stirring rate of 30 rpm for 45 minutes. The crude 2,4,6-triaminotoluene was dissolved and passed through a decolorizing filter membrane while hot to filter out insoluble impurities in the solution and decolorize to obtain a crude filtrate.

[0096] S103, transferring the crude filtrate into a second container, cooling the second container to a target cooling temperature, and slowly stirring the second container to precipitate a crystalline product.

[0097] The temperature of the reactor was cooled to 0°C, and stirring was continued at a stirring rate of 30 rpm for 45 minutes. At this time, due to the temperature drop, the supersaturated 2,4,6-triaminotoluene solution was fully crystallized within the stirring time to obtain a crystalline product.

[0098] S104, filtering to obtain a crystalline product, and drying the crystalline product to obtain a final product.

[0099] The crude product filtrate is filtered through a positive pressure filter (decolorizing filter membrane) to obtain a wet crystalline product, and most of the water in the wet crystalline product is absorbed by a suction filter to obtain a crystalline product; the crystalline product is placed in a vacuum dryer for heat preservation and drying, the drying temperature is 40°C, and the drying pressure is less than -0.01MPa to obtain a final product, the yield of the final product (based on the crude 2,4,6-triaminotoluene) is 80%, and the purity is 99.41%.

[0100] Figure 2 The nuclear magnetic resonance hydrogen spectrum of the final product in this embodiment is shown in FIG. Figure 2 As shown, 1H-NMR (400 MHz, CDCl3) δ (ppm): 5.31 (singlet, integral 2, CH), 4.20 (singlet, integral 6, NH2), 1.69 (singlet, integral 3, CH3), which are the benzene ring hydrogen, amino hydrogen and methyl hydrogen in 2,4,6-triaminotoluene, respectively, which are consistent with the structure of 2,4,6-triaminotoluene.

[0101] Figure 3 The carbon NMR spectrum of the final product in this embodiment is shown in FIG. Figure 3 As shown, 13 C-NMR (101 MHz, DMSO-D6) δ (ppm): 146.85, 146.33, 94.91, 92.05, 9.86, which are consistent with the structure of 2,4,6-triaminotoluene, and characterize the carbon at position 2 or 6, carbon at position 4, carbon at position 1, carbon at position 3 or 5, and methyl carbon in 2,4,6-triaminotoluene, respectively.

[0102] Figure 4 The infrared spectrum of the final product in this embodiment is shown in FIG. Figure 4 As shown, IR (KBr, cm-1): 3338 (s), 3224 (m), 2963 (s), 2920 (m), 2854 (m), 1615 (s), 1590 (m), 1513 (s), 1464 (m), 1267 (s), 1222 (w), 1172 (w), 1068 (m), 818 (w), 704 (w), among which the two peaks of 3338.18 and 3224.82 in the infrared spectrum characterize the presence of amino groups, which is consistent with the structure of 2,4,6-triaminotoluene.

[0103] Figure 5 The high-resolution mass spectrum of the final product in this embodiment is shown in FIG. Figure 5 As shown, HR-MS (EI): m / z 138.102630 [MH] - (found C7H 12 N3, required 138.102574), where the peak 138 characterizes the composition of the final product as C7H 12 N3, removing the protons emitted in the mass spectrometer electrospray mode, the composition of the final product is C7H 11 N3, which is consistent with the structure of 2,4,6-triaminotoluene.

[0104] Figure 6 The HPLC chromatogram of the final product in this embodiment is shown. Figure 6 As shown, the purity of the final product of this embodiment is 99.41%.

[0105] Embodiment 2

[0106] S101. Add a solvent and a crude 2,4,6-triaminotoluene into a first container according to a preset mass ratio, and perform deoxygenation and atmosphere replacement.

[0107] During the specific implementation, the first container and the second container are in a fully enclosed reactor with a jacket, 1.3kg of ethyl acetate and 0.04kg of water are added to the first container as a solvent (the mass ratio of ethyl acetate to water is 32.5:1), and 50g of 2,4,6-triaminotoluene crude product is quickly added to the solvent in the reactor to obtain a crude mixture. High-pressure nitrogen is connected to the reactor (the first container and the second container) to make the pressure in the reactor reach 1.0MPa, continue to stir for 10 minutes, then unload to normal pressure, repeat 3 times, and the deoxygenation operation of the reactor is considered to be completed. High-pressure nitrogen is connected to the reactor again to make the pressure in the reactor reach 1.0MPa, continue to stir for 10 minutes, then unload to normal pressure, repeat 3 times, and the atmosphere replacement of nitrogen is considered to be completed.

[0108] S102, heating the first container to the target dissolution temperature while slowly stirring, and passing the mixture through a decolorizing filter membrane while hot to obtain a crude filtrate.

[0109] The reactor was heated to 90°C and stirred at a stirring rate of 30 rpm for 30 minutes. At this time, the crude 2,4,6-triaminotoluene was dissolved. The crude product was passed through a decolorizing filter membrane while hot to filter out insoluble impurities in the solution and decolorize to obtain a crude filtrate.

[0110] S103, transferring the crude filtrate into a second container, cooling the second container to a target cooling temperature, and slowly stirring the second container to precipitate a crystalline product.

[0111] The temperature of the reactor was cooled to 20° C., and stirring was continued at a stirring rate of 30 rpm for 60 minutes. At this time, due to the temperature drop, the supersaturated 2,4,6-triaminotoluene solution was fully crystallized within the stirring time to obtain a crystalline product.

[0112] S104, filtering to obtain a crystalline product, and drying the crystalline product to obtain a final product.

[0113] The crude product filtrate is filtered through a positive pressure filter (decolorizing filter membrane) to obtain a wet crystalline product, and most of the water in the wet crystalline product is absorbed by a suction filter to obtain a crystalline product; the crystalline product is placed in a vacuum dryer for heat preservation and drying, the drying temperature is 60° C., and the drying pressure is less than -0.01 MPa to obtain a final product, the yield of the final product (based on the crude 2,4,6-triaminotoluene) is 75%, and the purity is 99.33%.

[0114] Figure 7 The HPLC chromatogram of the final product in this embodiment is shown. Figure 7 As shown, the purity of the final product of this embodiment is 99.33%.

[0115] Embodiment 3

[0116] S101. Add a solvent and a crude 2,4,6-triaminotoluene into a first container according to a preset mass ratio, and perform deoxygenation and atmosphere replacement.

[0117] During the specific implementation, the first container and the second container are fully enclosed reactors with jackets. 1kg of dioxane and 0.2kg of water are added to the first container as solvents (the mass ratio of dioxane to water is 5:1), and 800g of crude 2,4,6-triaminotoluene is quickly added to the solvent in the reactor to obtain a crude mixture. High-pressure nitrogen is connected to the reactor to make the pressure in the reactor reach 0.8MPa, stirring continuously for 10 minutes, and then unloading to normal pressure, repeating 3 times, and the deoxygenation operation of the reactor is considered to be completed. High-pressure nitrogen is connected to the reactor again, and the pressure in the reactor reaches 0.8MPa, stirring continuously for 10 minutes, and then unloading to normal pressure, repeating 3 times, and the atmosphere replacement of nitrogen is considered to be completed.

[0118] S102, heating the first container to the target dissolution temperature while slowly stirring, and passing the mixture through a decolorizing filter membrane while hot to obtain a crude filtrate.

[0119] The reactor was heated to 90°C and stirred at a stirring rate of 30 rpm for 35 minutes. At this time, the crude 2,4,6-triaminotoluene was dissolved. The crude product was passed through a decolorizing filter membrane while hot to filter out insoluble impurities in the solution and decolorize to obtain a crude filtrate.

[0120] S103, transferring the crude filtrate into a second container, cooling the second container to a target cooling temperature, and slowly stirring the second container to precipitate a crystalline product.

[0121] The temperature of the reactor was cooled to 20° C., and stirring was continued at a stirring rate of 30 rpm for 60 minutes. At this time, due to the temperature drop, the supersaturated 2,4,6-triaminotoluene solution was fully crystallized within the stirring time to obtain a crystalline product.

[0122] S104, filtering to obtain a crystalline product, and drying the crystalline product to obtain a final product.

[0123] The crude product filtrate is filtered through a positive pressure filter (decolorizing filter membrane) to obtain a wet crystalline product, and most of the water in the wet crystalline product is absorbed by a suction filter to obtain a crystalline product; the crystalline product is placed in a vacuum dryer for heat preservation and drying, the drying temperature is 60°C, and the drying pressure is less than -0.01MPa to obtain a final product, the yield of the final product (based on the crude 2,4,6-triaminotoluene) is 78%, and the purity is 99.13%.

[0124] Figure 8 The HPLC chromatogram of the final product in this embodiment is shown. Figure 8 As shown, the purity of the final product of this embodiment is 99.13%.

[0125] Embodiment 4

[0126] S101. Add a solvent and a crude 2,4,6-triaminotoluene into a first container according to a preset mass ratio, and perform deoxygenation and atmosphere replacement.

[0127] During the specific implementation, the first container and the second container are a fully enclosed reactor with a jacket, 1kg of acetonitrile and 0.15kg of water are added to the first container as a solvent (the mass ratio of acetonitrile to water is 100:15), and 60g of 2,4,6-triaminotoluene crude product is quickly added to the solvent in the reactor to obtain a crude mixture. High-pressure nitrogen is connected to the reactor, the pressure in the reactor reaches 0.8MPa, stirring continuously for 10 minutes, and then unloaded to normal pressure, repeated 3 times, and the deoxygenation operation of the reactor is considered to be completed. High-pressure nitrogen is connected to the reactor again, the pressure in the reactor reaches 0.8MPa, stirring continuously for 10 minutes, and then unloaded to normal pressure, repeated 3 times, and the atmosphere replacement of nitrogen is considered to be completed.

[0128] S102, heating the first container to the target dissolution temperature while slowly stirring, and passing the mixture through a decolorizing filter membrane while hot to obtain a crude filtrate.

[0129] The reactor was heated to 90°C and stirred at a stirring rate of 30 rpm for 35 minutes. At this time, the crude 2,4,6-triaminotoluene was dissolved. The crude product was passed through a decolorizing filter membrane while hot to filter out insoluble impurities in the solution and decolorize to obtain a crude filtrate.

[0130] S103, transferring the crude filtrate into a second container, cooling the second container to a target cooling temperature, and slowly stirring the second container to precipitate a crystalline product.

[0131] The temperature of the reactor was cooled to 20° C., and stirring was continued at a stirring rate of 30 rpm for 60 minutes. At this time, due to the temperature drop, the supersaturated 2,4,6-triaminotoluene solution was fully crystallized within the stirring time to obtain a crystalline product.

[0132] S104, filtering to obtain a crystalline product, and drying the crystalline product to obtain a final product.

[0133] The crude product filtrate is filtered through a positive pressure filter (decolorizing filter membrane) to obtain a wet crystalline product, and most of the water in the wet crystalline product is absorbed by a suction filter to obtain a crystalline product; the crystalline product is placed in a vacuum dryer for heat preservation and drying, the drying temperature is 60° C., and the drying pressure is less than -0.01 MPa to obtain a final product, the yield of the final product (based on the crude 2,4,6-triaminotoluene) is 85%, and the purity is 99.13%.

[0134] Embodiment 5

[0135] S101. Add a solvent and a crude 2,4,6-triaminotoluene into a first container according to a preset mass ratio, and perform deoxygenation and atmosphere replacement.

[0136] During the specific implementation, the first container and the second container are fully enclosed reactors with jackets. 1kg ethanol and 0.05kg water are added to the first container as solvents (the mass ratio of ethanol to water is 20: 1), and 20g of 2,4,6-triaminotoluene crude product is quickly added to the solvent in the reactor to obtain a crude mixture. High-pressure nitrogen is connected to the reactor, so that the pressure in the reactor reaches 0.8MPa, stirring is continued for 10 minutes, and then unloaded to normal pressure, repeated 3 times, and the deoxygenation operation of the reactor is considered to be completed. High-pressure nitrogen is connected to the reactor again, so that the pressure in the reactor reaches 0.8MPa, stirring is continued for 10 minutes, and then unloaded to normal pressure, repeated 3 times, and the atmosphere replacement of nitrogen is considered to be completed.

[0137] S102, heating the first container to the target dissolution temperature while slowly stirring, and passing the mixture through a decolorizing filter membrane while hot to obtain a crude filtrate.

[0138] The reactor was heated to 90°C and stirred at a stirring rate of 30 rpm for 35 minutes. At this time, the crude 2,4,6-triaminotoluene was dissolved. The crude product was passed through a decolorizing filter membrane while hot to filter out insoluble impurities in the solution and decolorize to obtain a crude filtrate.

[0139] S103, transferring the crude filtrate into a second container, cooling the second container to a target cooling temperature, and slowly stirring the second container to precipitate a crystalline product.

[0140] The temperature of the reactor was cooled to 20° C., and stirring was continued at a stirring rate of 30 rpm for 60 minutes. At this time, due to the temperature drop, the supersaturated 2,4,6-triaminotoluene solution was fully crystallized within the stirring time to obtain a crystalline product.

[0141] S104, filtering to obtain a crystalline product, and drying the crystalline product to obtain a final product.

[0142] The crude product filtrate is filtered through a positive pressure filter (decolorizing filter membrane) to obtain a wet crystalline product, and most of the water in the wet crystalline product is absorbed by a suction filter to obtain a crystalline product; the crystalline product is placed in a vacuum dryer for heat preservation and drying, the drying temperature is 60°C, and the drying pressure is less than -0.01MPa to obtain a final product, the yield of the final product (based on the crude 2,4,6-triaminotoluene) is 82%, and the purity is 99.0%.

[0143] The present application provides a method for purifying 2,4,6-triaminotoluene, wherein a specific hydrated organic solvent is added to a first container in an oxygen-free atmosphere to dissolve the crude 2,4,6-triaminotoluene at a target dissolution temperature, and then the crude 2,4,6-triaminotoluene is transferred to a second container, and the second container is cooled to a target cooling temperature. After the crystalline product is precipitated, it is filtered through a decolorizing membrane and dried to obtain a final product, which has the following effects:

[0144] (1) In the purification process, the present application uses a nitrogen atmosphere for protection throughout the entire process, thereby preventing 2,4,6-triaminotoluene from deteriorating due to oxidation during the purification process.

[0145] (2) The target dissolution temperature and target cooling temperature of the present application are determined based on the solubility of a specific hydrated organic solvent in dissolving 2,4,6-triaminotoluene at different temperatures, thereby improving the yield and purity of 2,4,6-triaminotoluene.

[0146] (3) The method provided in this application is simple to operate, has low solvent price, is green and safe, has high purification efficiency, and is conducive to industrial promotion.

[0147] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0148] The technical solution provided by the present application is described in detail above. The principle and implementation method of the present application are described in this article using specific examples. The description of the above embodiments is only used to help understand the present application, and the content of this specification should not be understood as limiting the present application. At the same time, for those of ordinary skill in the art, according to the present application, there will be different forms of changes in the specific implementation methods and application scopes. It is not necessary and impossible to list all the implementation methods here, and the obvious changes or modifications derived therefrom are still within the scope of protection of the present application.

Claims

1. A method for purifying 2,4,6-triaminotoluene, characterized in that: include: S101, adding a solvent and a crude product of 2,4,6-triaminotoluene into a first container according to a preset mass ratio, and performing a deoxygenation operation and an atmosphere replacement to obtain a crude product mixture; wherein, The first container is a fully enclosed reactor with a jacket, the solvent is formed by mixing 1kg of acetonitrile and 0.15kg of water, and the mass of the crude 2,4,6-triaminotoluene is 60g; high-pressure nitrogen is connected to the reactor to make the pressure in the reactor reach 0.8MPa, stirring is continued for 10 minutes, and then unloaded to normal pressure, and repeated 3 times, which is considered to be the completion of the deoxygenation operation of the reactor; high-pressure nitrogen is connected to the reactor again to make the pressure in the reactor reach 0.8MPa, stirring is continued for 10 minutes, and then unloaded to normal pressure, and repeated 3 times, which is considered to be the completion of the nitrogen atmosphere replacement; S102, heating the first container to the target dissolution temperature, stirring slowly at the same time, passing the container through a decolorizing filter membrane while hot to obtain a crude filtrate; wherein, The first container is heated to 90° C. and stirred at a stirring rate of 30 rpm for 35 minutes, at which time the crude 2,4,6-triaminotoluene is dissolved, and the solution is filtered through a decolorizing filter membrane while hot to remove insoluble impurities in the solution, and decolorized to obtain a crude filtrate; S103, transferring the crude filtrate into a second container, cooling the second container to a target cooling temperature, and slowly stirring to precipitate a crystalline product; wherein, The second container is a fully enclosed reactor with a jacket. The temperature of the second container is cooled to 20° C. and the stirring is continued at a stirring rate of 30 rpm for 60 minutes. At this time, due to the temperature reduction, the supersaturated 2,4,6-triaminotoluene solution is fully crystallized within the stirring time to form a crystalline product; S104, filtering to obtain a wet crystal product, and drying the crystal product to obtain a final product; wherein, After most of the water in the wet product of the crystallized product is sucked away by a suction filter, a crystallized product is obtained; the crystallized product is placed in a vacuum dryer for heat preservation and drying, the drying temperature is 60° C., and the drying pressure is less than -0.01 MPa, to obtain a final product 2,4,6-triaminotoluene with a yield of 85% and a purity of 99.13%.

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