TATB preparation method for promoting amination by using 1, 4-dioxane

Abstract

The invention discloses a TATB preparation method using 1, 4-dioxane to promote amination, and the method uses 1, 4-dioxane as a solvent to form a homogeneous reaction system, so as to improve the kinetic efficiency of amination reaction. According to the method, 1, 4-dioxane with both polarity and hydrophilicity is used as a medium, the phase interface limitation of a traditional heterogeneous system is broken through, an integrated process of homogeneous amination, efficient mass transfer and green recovery is constructed, the technical problems of low reaction rate, complex separation and high energy consumption in the prior art are solved, and the method is suitable for industrial production. And an efficient and green new way is provided for amination preparation of the TATB.

Description

Technical Field

[0001] This invention belongs to the field of energetic material preparation technology, and relates to the synthesis of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB), specifically to a method for preparing TATB using 1,4-dioxane-promoted amination. Background Technology

[0002] In the field of TATB amination preparation, traditional synthesis processes typically use toluene and water as reaction solvents. However, the immiscibility of toluene and water leads to a heterogeneous reaction system, resulting in the following technical bottlenecks: On the one hand, the heterogeneous interface severely restricts the effective collisions between TCTNB and ammonia molecules, resulting in low mass transfer efficiency, low molecular collision frequency, and slow reaction rate, often requiring 8 to 12 hours to complete the reaction, making it difficult to improve production efficiency; on the other hand, phase separation requires complex processes such as extraction, which not only consumes a lot of energy and has a low solvent recovery rate, thus increasing production costs, but also results in a high proportion of by-products and a large amount of wastewater discharge, making it difficult to meet the environmental protection and sustainability requirements of green chemistry.

[0003] Therefore, overcoming the mass transfer and separation barriers in heterogeneous systems and developing a new, efficient, and low-consumption method for the preparation of TATB by amination has become an urgent technical problem to be solved in this field. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a method for preparing TATB using 1,4-dioxane-promoted amination, thereby solving the technical problems of slow reaction rates and complex post-processing in the synthesis of TATB using heterogeneous systems, which leads to low production efficiency, high costs, and severe environmental pollution.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A method for preparing TATB using 1,4-dioxane-promoted amination, wherein the method uses 1,4-dioxane as a solvent to form a homogeneous reaction system, thereby improving the kinetic efficiency of the amination reaction; specifically including the following steps: Step 1, Amination reaction: First, add 1,4-dioxane to the reaction vessel, then add TCTNB, stir well to form a TCTNB solution; slowly add ammonia water to the TCTNB solution; then heat and carry out the amination reaction. Step 2, Product separation and purification: After the amination reaction is completed, the reaction mother liquor is cooled and crystallized, filtered, washed and dried to obtain the target TATB product; Step 3, solvent recovery: After the amination reaction is completed, the filtrate of 1,4-dioxane-ammonia water is collected, the filtrate is washed twice with water, then distilled and the fraction at 90°C is collected, which can be reused in the future.

[0006] The present invention also has the following technical features: Specifically, in step one, the molar ratio of TCTNB to ammonia is 1:(2-5), preferably 1:(3-4); the amount of 1,4-dioxane used is 5-10 times the mass of TCTNB, preferably 6-8 times.

[0007] Specifically, in step one, when preparing the TCTNB solution, the stirring conditions are: a rotation speed of 200–800 rpm, preferably 300–600 rpm; and a stirring time of 5–15 minutes.

[0008] Specifically, in step one, the amination reaction conditions are as follows: the reaction is carried out under atmospheric pressure or a pressure of 0.1–0.5 MPa, preferably atmospheric pressure. The reaction temperature is 50–100°C, preferably 60–90°C; and the reaction time is 2–6 hours.

[0009] Specifically, in step two, the crude product collected after filtration is washed with water, acetone, and water in sequence.

[0010] Specifically, in step two, the drying conditions are as follows: the filter cake obtained after washing is first dried under vacuum at 80-120°C for 6-12 hours, and then the temperature is raised to 150-200°C and dried for another 6-12 hours.

[0011] Specifically, the stability parameters of 1,4-dioxane meet the following conditions: at a reaction temperature of 50-100℃, in an ammonia system with pH=8-12, the hydrolysis rate is ≤0.5%, and it does not undergo side reactions with TCTNB, ammonia, or the target product, ensuring that the solvent can be recycled ≥5 times, and the solvent purity is ≥80% after recycling.

[0012] Specifically, a jacketed reactor with a temperature control module (temperature control accuracy ±1℃) and a variable frequency stirring system (stirring speed adjustable from 200 to 800 rpm) are used; the device integrates real-time monitoring functions for temperature, pressure and stirring speed.

[0013] Compared with the prior art, the present invention has the following technical effects: (I) This invention uses 1,4-dioxane as a solvent, which is both polar and hydrophilic, and can uniformly dissolve components such as TCTNB and ammonia, transforming the heterogeneous reaction into a homogeneous system. This eliminates mass transfer barriers at the phase interface, significantly increases the frequency of molecular collisions, and thus significantly accelerates the reaction rate. Compared to traditional heterogeneous systems (reaction time 8–12 hours), the reaction time of this invention is 2–6 hours, and the reaction rate is increased by 3–5 times. Simultaneously, compared to the traditional process (yield 86%), the final product yield of this invention is ≥95%, an increase of approximately 5%, and the by-product content is reduced by approximately 5%. Furthermore, because 1,4-dioxane has a moderate boiling point and strong stability, the remaining mother liquor can be subjected to vacuum distillation to achieve solvent recovery and product separation, reducing solvent consumption, simplifying the subsequent purification process, reducing the use of chemical reagents, and lowering the environmental impact.

[0014] In summary, this invention uses 1,4-dioxane, which has both polarity and hydrophilicity, as a medium to overcome the phase interface limitations of traditional heterogeneous systems and construct an integrated process of "homogeneous amination-efficient mass transfer-green recovery". This solves the technical problems of slow reaction rate, complex separation and high energy consumption in the prior art, and provides a new, efficient and green approach for the preparation of TATB amination.

[0015] (II) The preparation method of the present invention can be used in conjunction with a production line, which includes a batching unit, a homogeneous reaction unit, a solvent recovery device and a production line refining unit connected in sequence; wherein, the batching unit can accurately control the feeding ratio of TCTNB, ammonia and 1,4-dioxane, the homogeneous reaction unit can monitor the reaction process through infrared online monitoring, and the solvent recovery device and the filtration and drying unit can realize the integration of crystallization and filtration; compared with the traditional batch process, the production efficiency can be increased by 2 to 3 times, realizing the continuous reaction of the whole process of "feeding-reaction-separation-recovery". Attached Figure Description

[0016] Figure 1 This is a flowchart of the TATB preparation process in Example 1.

[0017] The specific content of the present invention will be further explained in detail below with reference to the embodiments. Detailed Implementation

[0018] It should be noted that, unless otherwise specified, the raw materials and products mentioned in this invention are all known in the art. For example, TCTNB refers to 1,3,5-trichloro-2,4,6-trinitrobenzene, with CAS code 2631-68-7. TATB refers to 1,3,5-triamino-2,4,6-trinitrobenzene, with CAS code 3058-38-6.

[0019] The technical concept of this invention is as follows: Traditional processes use toluene and water as reaction solvents, forming a heterogeneous system with interfacial mass transfer resistance, resulting in a low effective collision frequency of reactant molecules. This invention uses 1,4-dioxane as a solvent to promote the amination reaction between TCTNB and ammonia. 1,4-dioxane has a polarity parameter of 4.8-5.2 and a hydrophobicity parameter of log P value of 0.2-0.5 (exhibiting good hydrophilicity), enabling it to dissolve TCTNB (a polar organic compound). Furthermore, it is miscible with ammonia (a polar aqueous solution) using the principle of like dissolves like, transforming the reaction system from a heterogeneous (toluene-water two-phase system) in traditional processes into a homogeneous system. In this homogeneous system, the molecular collision frequency is effectively increased, eliminating the limitations imposed by the heterogeneous interface.

[0020] Following the above technical solutions and concepts, specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0021] Example 1: This embodiment provides a method for preparing TATB using 1,4-dioxane-promoted amination, such as... Figure 1 As shown, the method specifically includes the following steps: Step 1: Amination reaction is carried out. Step 1.1: Prepare TCTNB, 1,4-dioxane, and 28% ammonia solution. Accurately weigh 0.1 mol (31.6 g) of TCTNB using an electronic balance and transfer it to a 1000 mL three-necked flask containing 90 g of 1,4-dioxane. Turn on the stirrer and set the speed to 400 rpm, stirring continuously for 10 minutes. Observe the reaction system gradually change from turbid to clear and transparent, indicating the formation of a homogeneous solution. At this point, the homogeneous system is confirmed to have been successfully constructed by laser particle size analyzer.

[0022] Step 1.2: Measure 0.4 mol (48.5 g) of ammonia water and slowly add it to the reaction flask through a constant pressure dropping funnel.

[0023] Step 1.3: The reaction temperature was raised to 80 °C using a heating mantle and maintained constant, while the reaction system was kept at atmospheric pressure. In this embodiment, 0.5 mL of the reaction solution was taken every 30 minutes, diluted 10 times with methanol (chromatographic grade), and then analyzed by HPLC. The results showed that after 5 hours of reaction, the TCTNB conversion rate reached 85%; after continuing the reaction for another 3 hours, the conversion rate reached 96.8%. The peak area normalization method determined the content of the target product (TATB) to be 95.3%, and the total content of by-products was <2%. Moreover, the reaction kinetic data showed that the reaction rate constant of the system of this invention was significantly higher than that of the traditional toluene-water heterogeneous system.

[0024] Step 2, Product separation and purification: Step 2.1: After the reaction is complete, the reaction solution is cooled to room temperature, and a yellow solid slowly precipitates out. The solid is then transferred to a Buchner funnel and filtered under reduced pressure to obtain the yellow solid. The filtrate of 1,4-dioxane-ammonia water is collected.

[0025] Step 2.2: Subsequently, pre-wash once with purified water, transfer the obtained solid to a 1000 mL reaction flask, add acetone for two boiling washes, and then boil three times with purified water to remove impurities adhering to the surface.

[0026] Step 2.3: The filter cake was transferred to a vacuum drying oven and dried under vacuum at 100 °C for 8 hours. The temperature was then increased to 180 °C and dried for another 8 hours, ultimately yielding 24.6 g of a white solid product. In this embodiment, the product was analyzed by proton nuclear magnetic resonance spectroscopy (NMR 1H). 1 H NMR (400 MHz, DMSO- d 6) δ 10.01 (s, 1H)), exothermic decomposition peak (378 ℃), and FTIR (neat) spectra: υ 3316.0, 3216.2, 1602.6, 1441.4, 1209.6, 1161.9, 777.5 cm⁻¹ -1 By comparing relevant data, it was confirmed that the white solid product was indeed TATB, with a product yield of 96% and a purity of 98.6%.

[0027] Step 3, Solvent recovery: After the reaction is complete, the 1,4-dioxane mother liquor collected in step 2.1 is washed twice with water, mainly to remove inorganic salt compounds. The mother liquor is then preliminarily distilled. 1,4-dioxane (boiling point 101.3 ℃) forms an azeotrope with water (azeotropic temperature approximately 87 ℃). The directly separated solvent still contains some water (the water content can be directly measured). Since water is used in the reaction system, there is no need to strictly control the water content of the recovered solvent; simply reduce the amount of water used in the next use based on the test results.

[0028] Example 2: This embodiment provides a method for preparing TATB using 1,4-dioxane-promoted amination, which specifically includes the following steps: Step 1: Perform the amination reaction (adjusting the reaction concentration): Step 1.1: Prepare TCTNB, 1,4-dioxane, and 28% ammonia solution. Accurately weigh 0.1 mol (31.6 g) of TCTNB using an electronic balance and transfer it to a 1000 mL three-necked flask containing x g (see table below) of 1,4-dioxane. Turn on the stirrer and set the speed to 400 rpm, stirring continuously for 10 minutes. Observe the reaction system gradually change from turbid to clear and transparent, indicating the formation of a homogeneous solution. At this time, the homogeneous system is confirmed to have been successfully constructed by laser particle size analyzer.

[0029] Step 1.2: Measure 0.4 mol (48.5 g) of ammonia water and slowly add it to the reaction flask through a constant pressure dropping funnel.

[0030] Step 1.3: The reaction temperature is raised to 80 °C using a heating mantle and kept constant, while the reaction system is kept at atmospheric pressure.

[0031] Step 2, Product Separation and Purification: In this embodiment, Step 2 is exactly the same as Step 2 in Example 1. The target product TATB was confirmed to have been synthesized, and the product yield and purity are shown in Table 1 below.

[0032] Table 1. Product yield and purity of Example 2

[0033] Step 3, solvent recovery: In this embodiment, step 3 is exactly the same as step 3 in embodiment 1.

[0034] Example 3: This embodiment provides a method for preparing TATB using 1,4-dioxane-promoted amination, which specifically includes the following steps: Step 1: Amination reaction (solvent selection): Step 1.1: Prepare TCTNB, 1,4-dioxane, and 28% ammonia solution. Accurately weigh 0.1 mol (31.6 g) of TCTNB using an electronic balance and transfer it to a 1000 mL three-necked flask containing 90 g of solvent. Turn on the stirrer and set the speed to 400 rpm, stirring continuously for 10 minutes. Observe the reaction system gradually change from turbid to clear and transparent, indicating the formation of a homogeneous solution. At this time, the homogeneous system is confirmed to have been successfully constructed by laser particle size analyzer.

[0035] Step 1.2: Measure 0.4 mol (48.5 g) of ammonia water and slowly add it to the reaction flask through a constant pressure dropping funnel.

[0036] Step 1.3: The reaction temperature is raised to 80 °C using a heating mantle and kept constant, while the reaction system is kept at atmospheric pressure.

[0037] Step 2, Product Separation and Purification: In this embodiment, Step 2 is exactly the same as Step 2 in Example 1. The target product TATB was confirmed to have been synthesized, and the product yield and purity are shown in Table 2 below.

[0038] Table 2. Product yield and purity of Example 3

[0039] Step 3, Solvent Recovery: In this embodiment, 1,4-dioxane is exactly the same as in Step 3 of Example 1. Xylene is not recovered; toluene is returned to the production line for centralized recovery.

[0040] Example 4: This embodiment provides a method for preparing TATB using 1,4-dioxane-promoted amination, which specifically includes the following steps: Step 1: Amination reaction (adjustment of the ratio of ammonia to raw materials): Step 1.1: Prepare TCTNB, 1,4-dioxane, and 28% ammonia solution. Accurately weigh 0.1 mol (31.6 g) of TCTNB using an electronic balance and transfer it to a 1000 mL three-necked flask containing 90 g of 1,4-dioxane. Turn on the stirrer and set the speed to 400 rpm, stirring continuously for 10 minutes. Observe the reaction system gradually change from turbid to clear and transparent, indicating the formation of a homogeneous solution. At this point, the homogeneous system is confirmed to have been successfully constructed by laser particle size analyzer.

[0041] Step 1.2: Measure x mol of ammonia water and slowly add it to the reaction flask through a constant pressure dropping funnel.

[0042] Step 1.3: The reaction temperature is raised to 80 °C using a heating mantle and kept constant, while the reaction system is kept at atmospheric pressure.

[0043] Step 2, Product Separation and Purification: In this embodiment, Step 2 is exactly the same as Step 2 in Example 1. The target product TATB was confirmed to have been synthesized, and the product yield and purity are shown in Table 3 below.

[0044] Table 3. Product yield and purity of Example 4

[0045] Step 3, solvent recovery: In this embodiment, step 3 is exactly the same as step 3 in embodiment 1.

[0046] Example 5: This embodiment provides a method for preparing TATB using 1,4-dioxane-promoted amination, which specifically includes the following steps: Step 1: Amination reaction (reaction temperature): Step 1.1: Prepare TCTNB, 1,4-dioxane, and 28% ammonia solution. Accurately weigh 0.1 mol (31.6 g) of TCTNB using an electronic balance and transfer it to a 1000 mL three-necked flask containing 90 g of 1,4-dioxane. Turn on the stirrer and set the speed to 400 rpm, stirring continuously for 10 minutes. Observe the reaction system gradually change from turbid to clear and transparent, indicating the formation of a homogeneous solution. At this point, the homogeneous system is confirmed to have been successfully constructed by laser particle size analyzer.

[0047] Step 1.2: Measure 0.4 mol (48.5) of ammonia water and slowly add it to the reaction flask through a constant pressure dropping funnel.

[0048] Step 1.3: Raise the reaction temperature to T (see table below) °C using a heating mantle and keep it constant, while maintaining the reaction system at atmospheric pressure.

[0049] Step 2, Product Separation and Purification: In this embodiment, Step 2 is exactly the same as Step 2 in Example 1. The target product TATB was confirmed to have been synthesized, and the product yield and purity are shown in Table 4 below.

[0050] Table 4. Product yield and purity of Example 5

[0051] Step 3, solvent recovery: In this embodiment, step 3 is exactly the same as step 3 in embodiment 1.

Claims

1. A method for preparing TATB using 1,4-dioxane-promoted amination, characterized in that, This method uses 1,4-dioxane as a solvent to form a homogeneous reaction system, thereby improving the kinetic efficiency of the amination reaction. The method includes: first, adding 1,4-dioxane to a reaction vessel, then adding TCTNB, stirring until homogeneous to form a TCTNB solution; slowly adding ammonia to the TCTNB solution; and then heating and carrying out an amination reaction.

2. The method for preparing TATB using 1,4-dioxane-promoted amination as described in claim 1, characterized in that, The molar ratio of TCTNB to ammonia is 1:(2-5); the amount of 1,4-dioxane is 5-10 times the mass of TCTNB.

3. The method for preparing TATB using 1,4-dioxane-promoted amination as described in claim 1, characterized in that, When preparing TCTNB solution, the stirring conditions are: 200–800 rpm; stirring time is 5–15 minutes.

4. The method for preparing TATB using 1,4-dioxane-promoted amination as described in claim 1, characterized in that, The amination reaction conditions are as follows: the reaction is carried out under normal pressure or under pressure of 0.1 to 0.5 MPa; the reaction temperature is 50 to 100°C; and the reaction time is 2 to 6 hours.

5. The method for preparing TATB using 1,4-dioxane-promoted amination as described in claim 1, characterized in that, The method also includes: after the amination reaction is completed, the reaction mother liquor is cooled and crystallized, filtered, washed and dried to obtain the target TATB product.

6. The method for preparing TATB using 1,4-dioxane-promoted amination as described in claim 5, characterized in that, The crude product collected after filtration was washed with water, acetone and water in sequence.

7. The method for preparing TATB using 1,4-dioxane-promoted amination as described in claim 5, characterized in that, The drying conditions are as follows: the filter cake obtained after washing is first dried under vacuum at 80-120 ℃ for 6-12 hours, and then the temperature is raised to 150-200 ℃ and dried for another 6-12 hours.

8. The method for preparing TATB using 1,4-dioxane-promoted amination as described in claim 5, characterized in that, The method also includes: after the amination reaction is completed, collecting the filtrate of 1,4-dioxane-ammonia water, washing the filtrate twice with water, then distilling and collecting the fraction at 90°C for subsequent reuse.

9. The method for preparing TATB using 1,4-dioxane-promoted amination as described in claim 1, characterized in that, The stability parameters of 1,4-dioxane meet the following conditions: at a reaction temperature of 50-100℃, in an ammonia system with pH=8-12, the hydrolysis rate is ≤0.5%, and it does not undergo side reactions with TCTNB, ammonia, or the target product, ensuring that the solvent can be recycled ≥5 times, and the solvent purity is ≥80% after recycling.

10. The method for preparing TATB using 1,4-dioxane-promoted amination as described in claim 1, characterized in that, A jacketed reactor with a temperature control module is used to achieve precise control of the reaction temperature, with a temperature control accuracy of ±1℃; an adjustable-speed variable frequency stirring system is used to achieve stirring and form a homogeneous system; the dedicated reaction device integrates temperature, pressure and stirring rate, and has real-time monitoring function.

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