Method for continuous flow photochemical synthesis of benzofuranzan
By introducing continuous flow chemical synthesis technology in traditional explosive synthesis, the problems of low safety, long synthesis cycle and high energy consumption in traditional methods are solved, and the efficient synthesis of benzofurotrioxide under room temperature conditions is achieved, which improves production efficiency and safety.
Patent Information
- Application Number
- CN202510405354.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-01
- Publication Date
- 2025-06-27
AI Technical Summary
Traditional thermal chemical synthesis methods of explosives have problems such as low safety, long synthesis cycle, high energy consumption and poor equipment tolerance, making it difficult to control the reaction temperature and easily cause accidents such as material spraying, burning and explosion.
The continuous flow photochemical synthesis method is adopted to deeply fusion of photochemistry and continuous flow technology to achieve photochemical reactions under room temperature conditions, reducing the reaction risk, and real-time monitoring and adjustment of reaction conditions through the flow chemical system.
It significantly improves the safety and production efficiency of benzofurotrioxide, shortens the synthesis cycle, reduces energy consumption and equipment wear, and reduces safety risks and environmental impact.
Smart Images
Figure CN120208987A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of organic synthesis, and particularly to a method for continuously synthesizing benzotrioxide furazan by flow chemistry. Background Art
[0002] As a key energy material for modern weapon systems to achieve efficient damage, the energy level, safety, and thermal stability of explosives directly affect the overall combat effectiveness of weaponry and are the cornerstone materials for national defense security construction. However, explosive molecules are metastable substances and are prone to rapid decomposition under external stimuli, leading to hazards such as combustion and explosion. Therefore, there are safety risks such as combustion and explosion in their synthesis and preparation, which poses high safety requirements for explosive synthesis technologies. However, traditional thermal chemical synthesis methods for explosives are difficult to control the reaction temperature. Once the temperature gets out of control, it is easy to cause accidents such as spraying and detonation, and there is an urgent need to develop new explosive synthesis technologies with higher safety.
[0003] Furazan compounds are one of the research hotspots in the field of energetic materials. When an oxidation furazan group is introduced into a compound molecule to replace a nitro group, not only does its density increase by 0.06 g / cm 3 ~0.08 g / cm 3 but also the detonation velocity will increase by about 300 m / s. Due to the reduction of hydrogen content, improvement of oxygen balance, and increase of detonation pressure in the molecules of energetic oxidation furazan structures, energetic oxidation furazan-containing compounds have attracted great attention from energetic materials experts. Benzotrioxide furazan (BTF) is obtained by introducing oxidation furazan to replace nitro groups on the benzene ring and is an ideal hydrogen-free explosive in the benzene ring series. It has good initiation performance, detonation energy, safety, and thermal stability and is an excellent primary explosive. Currently, the synthesis method of BTF is relatively complex, requiring heating to extremely high temperatures in expensive acidic solutions to remove three molecules of nitrogen gas, which has the disadvantages of high pollution, high energy consumption, and high safety risks. At the same time, maintaining a high reaction temperature places higher requirements on the tolerance of production equipment, easily leading to equipment wear, damage, and aging. High-temperature environments are usually accompanied by higher safety risks. Operators may face heat sources, steam, explosion of active intermediates, or other dangerous conditions, so additional safety measures need to be taken to ensure the health and safety of employees. High-temperature reactions are usually accompanied by higher energy consumption, which may lead to other environmental impacts. These problems affect the cost and safety of BTF industrial production and restrict the application of BTF.
[0004] Therefore, there is an urgent need for a synthesis method of BTF with high safety, simple synthesis conditions, low energy consumption, and short synthesis cycle. Summary of the Invention
[0005] The object of the present invention is to provide a method for continuously flowing photochemical synthesis of benzotrioxide furazan to solve the problems of complex synthesis conditions, low safety, and long synthesis cycle in the above-mentioned synthesis method of BTF. The present invention uses a method of combining flow chemistry synthesis with photochemical synthesis. Through the deep integration of photochemistry and continuous flow technology, the bottlenecks of safety, selectivity, and efficiency in traditional synthesis are solved, and at the same time, a new method for the green preparation of energetic compounds (such as benzotrioxide furazan) is provided. The continuous flow photochemical synthesis of the present invention is carried out under continuous flow conditions, and the amounts of reactants and products are small, thus reducing the risks of explosion and fire. The flow chemistry system can monitor and adjust reaction conditions in real time, such as temperature, pressure, concentration, etc., which helps to prevent runaway reactions. Flow chemistry synthesis can achieve rapid mixing and reaction, shorten the reaction time, and improve production efficiency. Flow chemistry synthesis is convenient for rapid optimization and iteration of process parameters, which helps the development of new products and the improvement of existing processes. In short, the flow chemistry synthesis of energetic compounds is of great significance in improving safety, production efficiency, product quality, and reducing costs, and has a positive effect on promoting the technological progress and sustainable development of the energetic materials industry.
[0006] To achieve the above object, a method for continuously flowing photochemical synthesis of benzotrioxide furazan according to the present invention comprises the following steps: (1) Dissolve raw material 1,3,5-triazido-2,4,6-trinitrobenzene (TATNB) in a solvent to obtain a raw material solution; (2) Pass the raw material solution into a continuous flow coil, and at the same time irradiate the continuous flow coil with light. After the reaction, an effluent solution is obtained; (3) Pass the effluent solution into a flask and evaporate the solvent to dryness to obtain benzotrioxide furazan (BTF).
[0007] Preferably, in step (1), the solvent is at least one of acetone, water, acetonitrile, and DMSO.
[0008] Preferably, in step (1), the ratio of 1,3,5-triazido-2,4,6-trinitrobenzene to the solvent is 1 mmol:(10 - 100) mL.
[0009] Preferably, in step (2), the flow rate of the raw material solution passing into the continuous flow coil is 1 mL / min - 20 mL / min.
[0010] Preferably, in step (2), the reaction temperature is room temperature.
[0011] Preferably, in step (2), the reaction time is 2 min - 1 h.
[0012] Preferably, in step (2), the light source for irradiation is one of an LED lamp and a metal halide lamp, and the wavelength of the light source is 255 - 500 nm.
[0013] Preferably, in step (2), the power of the light source is 1W - 100W.
[0014] Therefore, the method for continuously flowing photochemical synthesis of benzotrioxide furazan of the present invention has the following beneficial effects: (1) The present invention synthesizes benzotrioxide furazan by continuous flowing photochemistry. Under the condition of continuous flow, the photochemical reaction is carried out with a small amount of reactants and products, thus reducing the risks of explosion and fire. The flow chemistry system can also monitor and adjust reaction conditions such as temperature, pressure, concentration, etc. in real time, which helps to prevent runaway reactions. Flow chemistry synthesis can also achieve rapid mixing and reaction, shortening the reaction time and improving production efficiency. Flow chemistry synthesis is also convenient for rapid optimization and iteration of process parameters, which helps the development of new products and the improvement of existing processes. In short, the flow chemistry synthesis of energetic compounds is of great significance in improving safety, production efficiency, product quality and reducing costs.
[0015] (2) The present invention combines flow chemistry synthesis and photochemical synthesis. The continuous flowing photocatalytic reaction reduces the irradiation time, lowers energy consumption and increases the product yield.
[0016] (3) Compared with the traditional process that requires a heating temperature of 145°C, the present invention significantly reduces the reaction temperature to room temperature and eliminates the need for acidic solvents at the same time, which is green and environmentally friendly.
[0017] (4) The present invention solves the bottlenecks of safety, selectivity and efficiency in traditional synthesis, and at the same time provides a new method for the green preparation of energetic compounds (such as benzotrioxide furazan). These advantages highlight its strong practical application potential.
[0018] The technical solution of the present invention will be further described in detail below through the drawings and examples. Description of the Drawings
[0019] Figure 1 is the reaction flow chart of the present invention; Figure 2 is the nuclear magnetic carbon spectrum of the reaction product. Detailed Embodiments
[0020] The present invention will be further described below. It should be noted that this embodiment is based on the present technical solution and gives detailed implementation manners and specific operation processes, but the present invention is not limited to this embodiment.
[0021] Example 1 As Figure 1 shown, a method for continuously flowing photochemical synthesis of benzotrioxide furazan includes the following steps: (1) Dissolve 0.3 mmol of 1,3,5-triazido-2,4,6-trinitrobenzene (TATNB) in 10 mL of acetonitrile to obtain a 0.03 M stock solution; (2) Introduce the stock solution into a continuous flow coil through a peristaltic pump, control the flow rate of the stock solution at 20 mL / min, and simultaneously irradiate the continuous flow coil with light. Use a 470 nm LED to irradiate the area, maintain for 15 min, the power of the LED is 5 W, and the temperature is at room temperature. After the reaction, an effluent is obtained; (3) Pass the collected effluent into a flask, remove the solvent by vacuum distillation, and perform recrystallization using toluene to obtain benzotrioxide furazan. The yield of benzotrioxide furazan is 77%.
[0022] The carbon-13 NMR spectrum of the reaction product benzotrioxide furazan is shown in Figure 2 . From Figure 2 it can be seen that using deuterated DMSO as the solvent, the carbon-13 NMR spectrum of the product BTF has two characteristic peaks, which are 141.22 ppm and 102.55 ppm respectively.
[0023] Example 2 A method for the photochemical synthesis of benzotrioxide furazan, comprising the following steps: (1) Dissolve 1 mmol of 1,3,5-triazido-2,4,6-trinitrobenzene (TATNB) in 20 mL of ethanol to obtain a 0.05 M stock solution; (2) Irradiate the stock solution with light at room temperature. Use a 470 nm LED to irradiate the stock solution, stir and react for 10 h, the power of the LED is 5 W, and after the reaction, a reaction solution is obtained; (3) Pass the collected reaction solution into a flask, remove the solvent by vacuum distillation, and perform recrystallization using toluene to obtain benzotrioxide furazan. The yield of benzotrioxide furazan is 71%.
[0024] Compared with Example 1, in Example 2, only the photochemical synthesis method was used to prepare BTF, and a continuous flow coil was not used. It can be seen that if a product yield similar to that of Example 1 is to be obtained, a reaction time of 10 h is required, and the reaction time is greatly extended.
[0025] Example 3 A method for the photochemical synthesis of benzotrioxide furazan, comprising the following steps: (1) Dissolve 1 mmol of 1,3,5-triazido-2,4,6-trinitrobenzene (TATNB) in 10 mL of acetone to obtain a 0.1 M stock solution; (2) Irradiate the stock solution with light at room temperature. Use a 295 nm LED to irradiate the stock solution, stir and react for 10 h, the power of the LED is 10 W, and after the reaction, a reaction solution is obtained; (3) The collected reaction solution was introduced into a flask, and the solvent was removed by vacuum distillation to obtain benzotrioxide furazan (BTF). The yield of benzotrioxide furazan was 28%.
[0026] Compared with Example 2, the wavelength of the LED was changed in Example 3, which resulted in a yield of only 28% of the product BTF prepared in Example 3. This shows that the wavelength of the light in the present invention is very important, and the yield decreases when the wavelength is changed.
[0027] Example 4 A method for continuously synthesizing benzotrioxide furazan by flow chemistry, comprising the following steps: (1) Dissolve 1 mmol of 1,3,5-triazido-2,4,6-trinitrobenzene (TATNB) in 10 mL of acetonitrile to obtain a 0.1 M raw material solution; (2) Introduce the raw material solution into a continuous flow coil through a peristaltic pump, control the flow rate of the raw material solution to be 20 mL / min, and at the same time irradiate the continuous flow coil with light. The irradiation area uses an LED with a wavelength of 470 nm, and it is maintained for 15 min. The power of the LED is 5 W, and the temperature is room temperature. After the reaction, an effluent is obtained; (3) Introduce the collected effluent into a flask, remove the solvent by vacuum distillation, and perform recrystallization with toluene to obtain benzotrioxide furazan. The yield of benzotrioxide furazan is 71%.
[0028] Compared with Example 1, the concentration of the raw material solution in Example 4 is different, and the yield of the target compound is slightly lower.
[0029] Example 5 When directly refluxing the TATNB raw material solution without light irradiation, only a small amount (<10%) of BTF is produced, and a large amount of unreacted TATNB remains, including the following steps: (1) Dissolve 0.3 mmol of 1,3,5-triazido-2,4,6-trinitrobenzene (TATNB) in 10 mL of acetonitrile to obtain a 0.03 M raw material solution; (2) Introduce the raw material solution into a continuous flow coil through a peristaltic pump, control the flow rate of the raw material solution to be 20 mL / min, and maintain it for 2 h. The temperature is room temperature. After the reaction, an effluent is obtained; (3) Introduce the collected effluent into a flask, remove the solvent by vacuum distillation, and perform recrystallization with toluene to obtain a yield of benzotrioxide furazan <10%.
[0030] Compared with Example 1, the light irradiation was cancelled in Example 5, and the target compound was difficult to be effectively synthesized.
[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions of the present invention or make equivalent replacements, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.
Claims
1. A method for continuous flow photochemical synthesis of benzotrifuroxan, characterized in that: The following steps are involved: (1) dissolving the raw material 1,3,5-triazido-2,4,6-trinitrobenzene in a solvent to obtain a raw material liquid; (2) passing the raw material liquid into the continuous flow coil, and irradiating the continuous flow coil with light at the same time, and obtaining an effluent liquid after reaction; (3) The effluent was passed into a flask and the solvent was evaporated to obtain benzotrioxide.
2. The method for continuous flow photochemical synthesis of benzotrifuroxan according to claim 1, characterized in that: In step (1), the solvent is at least one of acetone, water, acetonitrile and DMSO.
3. The method for continuous flow photochemical synthesis of benzotrifuroxan according to claim 1, characterized in that: In step (1), the ratio of 1,3,5-triazido-2,4,6-trinitrobenzene to the solvent is 1 mmol: (10-100) mL.
4. The method for continuous flow photochemical synthesis of benzotrifuroxan according to claim 1, characterized in that: In step (2), the flow rate of the raw material liquid into the continuous flow coil is 1 mL / min~20 mL / min.
5. The method for continuous flow photochemical synthesis of benzotrifuroxan according to claim 1, characterized in that: In step (2), the reaction temperature is room temperature.
6. The method for continuous flow photochemical synthesis of benzotrifuroxan according to claim 1, characterized in that: In step (2), the reaction time is 2 min to 1 h.
7. The method for continuous flow photochemical synthesis of benzotrifuroxan according to claim 1, characterized in that: In step (2), the light source is an LED lamp or a metal halide lamp, and the wavelength of the light source is 255-500 nm.
8. The method for continuous flow photochemical synthesis of benzotrifuroxan according to claim 1, characterized in that: In step (2), the power of the light source is 1W~100W.