Preparation method of 3, 5, 7-trinitro-1-oxo-3, 5, 7-triazacyclooctane
TNOA was extracted from RDX waste drug by column chromatography. The method utilizes silica gel stationary phase separation and solvent elution to fill the gap in TNOA synthesis methods, achieving efficient and low-cost TNOA preparation suitable for industrial production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ZHONGBEI UNIV
- Filing Date
- 2026-04-13
- Publication Date
- 2026-05-19
AI Technical Summary
There is currently no synthetic method for 3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane (TNOA) in the technology. Its detonation velocity and detonation pressure are slightly lower than those of HMX, but its safety performance is better than that of HMX. It has good detonation performance and low mechanical sensitivity, and is expected to become a new type of high-energy explosive.
TNOA was extracted from waste products in the acetic anhydride preparation of RDX using column chromatography. Separation was achieved using chromatographic silica gel stationary phase, taking advantage of polarity differences. Elution was performed using solvent systems with different ratios of ethyl acetate and petroleum ether. The eluent was monitored by an online ultraviolet detector, and high-purity TNOA crystals were obtained by evaporation and crystallization.
It enables efficient and simple preparation of high-purity TNOA crystals, reducing production costs and environmental pollution, and is suitable for large-scale industrial production.
Smart Images
Figure CN122059902A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of energetic materials technology, specifically relating to a method for preparing 3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane. Background Technology
[0002] 3,5,7-Trinitol-1-oxo-3,5,7-triazacyclooctane (TNOA) is a white crystalline solid with a density of 1.83 g / cm³. 3 With a melting point of 219.8℃, it is an eight-membered energetic heterocyclic nitramine. Its ring skeleton consists of one O atom, three N atoms, and four C atoms. All three nitrogen atoms on the ring are attached to nitro groups (—NO2). In this molecule, an oxygen atom replaces one nitrogen atom on the octogen (HMX) ring, forming an oxy-nitrogen heterocyclic nitramine structure. Compared to the typical high-energy-density nitramine explosive octogen (HMX), both are eight-membered cyclic nitramine compounds with similar structures, as shown in the following structural formula:
[0003] TNOA structural formula: HMX structure: ;
[0004] Calculations using ExploML software show that 3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane (TNOA) has a detonation velocity of 8423.02 m / s, a detonation pressure of 31.80 GPa, and an impact sensitivity of 18.47 J. Compared to HMX (detonation velocity 9100 m / s, detonation pressure 39.50 GPa), TNOA has slightly lower detonation velocity and pressure, but its safety performance is superior. Overall, TNOA possesses good detonation performance and low mechanical sensitivity, making it a promising new type of high-energy explosive.
[0005] There are currently no literature reports on the synthesis method of TNOA. Summary of the Invention
[0006] The purpose of this invention is to address the problems existing in the prior art by providing a method for preparing 3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane (TNOA). This invention utilizes column chromatography to prepare 3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane from waste materials generated during the acetic anhydride process for preparing RDX.
[0007] This invention is achieved through the following technical solution: A method for preparing 3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane is disclosed, which utilizes column chromatography. Column chromatography separates sample molecules based on the differences in their adsorption capacity on a silica gel stationary phase. Stronger polar components are easily adsorbed by silica gel, while weaker polar components have weaker adsorption capacity. The separation process is a dynamic process of adsorption, desorption, re-adsorption, and re-desorption. This method has high separation efficiency and can separate compounds with similar structures and properties. It can be used for the separation of small quantities of samples as well as for the separation, purification, and preparation of larger quantities of materials.
[0008] The specific method includes the following steps: (1) Take the waste drug generated during the preparation of RDX by acetic anhydride and place it in a stirred reaction vessel. Add organic solvent, stir to dissolve, filter to remove insoluble matter, and obtain filtrate. Add deionized water to the obtained filtrate and stir evenly to obtain a mixture. Transfer the mixture to an oil-water separator, let it stand and separate into layers, and separate the upper organic phase from the upper part of the oil-water separator. Evaporate the organic phase under a negative pressure of 0.09 MPa and concentrate it to 1 / 10 of the original volume to obtain a concentrated solution.
[0009] (2) Add chromatographic grade silica gel powder to the concentrate obtained in step (1), stir evenly, and dry to obtain sample-mixed silica gel.
[0010] (3) Take another chromatographic grade silica gel powder and pack it into the chromatography column. Compact the packing and use the sample-mixed silica gel obtained in step (2) as a sample to spread evenly on the top of the chromatography column. Then place filter cloth and sieve plate on top and install the end cap.
[0011] (4) Prepare two elution systems with different ratios, namely organic solvent system A and organic solvent system B. Organic solvent system A is ethyl acetate and petroleum ether in a volume ratio of 30:70, and organic solvent system B is ethyl acetate and petroleum ether in a volume ratio of 31:69~35:65. First, use organic solvent system A to elute the chromatography column, and then use organic solvent system B to continue eluting. Collect the eluent from organic solvent system B.
[0012] (5) Evaporation crystallization is used to evaporate the effluent collected in step (4), then cool it to room temperature, filter it, and dry it to obtain TNOA crystals, which are the 3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane.
[0013] Furthermore, in step (1), the organic solvent is ethyl acetate, the mass of ethyl acetate added is 5 to 10 times the mass of the waste drug, and the stirring and dissolving time is 30 min.
[0014] Furthermore, in step (1), the mass of deionized water added is 3 to 4 times the mass of the organic solvent, and the stirring time is 30 min.
[0015] Furthermore, in step (2), the mass of chromatographic grade silica gel powder added is 0.1 to 0.3 times the mass of waste drug, and the stirring time during the sample mixing process is 30 min.
[0016] Furthermore, in step (3), the amount of chromatographic grade silica powder added is the capacity of the chromatography column minus the amount of sample-mixing silica powder added, that is, the amount of chromatographic grade silica powder plus the amount of sample-mixing silica powder in the chromatography column is just enough to fill the chromatography column.
[0017] Furthermore, in steps (2) and (3), the particle size of the chromatographic grade silica gel powder is 300~400 mesh.
[0018] Furthermore, in step (4), 29 to 32 column volumes of organic solvent system A are used for elution, and 3 to 5 column volumes of organic solvent system B are used for elution.
[0019] Furthermore, in step (4), the elution process uses an online ultraviolet detector to monitor the effluent.
[0020] Further, in step (4), the elution from organic solvent system B (ethyl acetate and petroleum ether in a volume ratio of 31:69~35:65) is the target fraction. The detection wavelength is set to 254 nm. The system is qualified if the baseline is stable and there are no obvious impurity peaks. During the elution process, when an obvious absorption peak appears and the peak shape is stable, the target fraction is collected. When the absorption peak signal drops to the baseline, the collection is stopped.
[0021] Furthermore, in step (5), the evaporation temperature is 40°C, and the collected effluent is evaporated to 1 / 10 of its original volume; the drying temperature is 40°C, and the drying time is 1 hour.
[0022] The method of this invention is based on scientific principles, is simple to operate, and has high preparation efficiency. The column chromatography method used is mild and has good reproducibility. Both the stationary phase and the mobile phase can be recycled and reused, which reduces production costs and environmental pollution, is conducive to large-scale production, and is applicable to industrial production. Attached Figure Description
[0023] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 The image shows the high performance liquid chromatography (HPLC) result of 3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane (TNOA) prepared by the method in Example 1 of this invention.
[0024] Figure 2 The image shows the DSC diagram of 3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane (TNOA) prepared by the method in Example 1 of this invention.
[0025] Figure 3 The above is the 1H NMR spectrum of 3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane (TNOA) prepared by the method in Example 1 of this invention.
[0026] Figure 4 The image shows the carbon NMR spectrum of 3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane (TNOA) prepared by the method in Example 1 of this invention. Detailed Implementation
[0027] To enable those skilled in the art to better understand the present invention, the embodiments of the present invention will be described in detail below with reference to the examples. The following examples are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention. Example 1
[0028] A method for preparing 3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane involves taking 5 kg of waste drug generated during the production of RDX via the acetic anhydride method, placing it in a stirred reactor, adding 25 kg of ethyl acetate and stirring to dissolve it for 30 min, filtering to remove insoluble matter, adding 75 kg of deionized water to the filtrate, and stirring for 30 min to obtain a mixture; transferring the mixture to an oil-water separator, allowing it to stand and separate into layers, separating the upper organic phase, placing the organic phase in an evaporator and evaporating it under a negative pressure of 0.09 MPa until 3 L is obtained as a concentrated solution.
[0029] Add 0.5 kg of chromatographic grade silica gel powder (300~400 mesh) to the concentrate, stir for 30 min, and air dry to obtain the mixed silica gel.
[0030] Take another 9.5 kg of chromatography-grade silica gel powder (300~400 mesh) and load it into... Φ In a 20cm×75cm chromatography column, pack the column and compact it, elute to equilibrium, spread the sample-mixed silica gel evenly on the top of the chromatography column, then place the filter cloth and sieve plate on top, and install the end cap.
[0031] First, elution was performed using organic solvent system A (eluent A), prepared with ethyl acetate and petroleum ether at a volume ratio of 30:70, for 29 column volumes (493 L). Then, organic solvent system B (eluent B), prepared with ethyl acetate and petroleum ether at a volume ratio of 35:65, was used for another 3 column volumes (51 L). After elution, the eluent from organic solvent system B was collected. The entire elution process was monitored using an online UV detector. The target fraction collection program was started simultaneously when elution began with organic solvent system B: the target fraction was collected when a clear absorption peak appeared on the chromatogram and the peak shape stabilized. Collection was stopped when the absorption peak signal returned to the baseline, and 51 L of the target fraction eluent was finally obtained.
[0032] The collected effluent was evaporated to 5.1 L at an evaporation temperature of 40 °C, then cooled to room temperature, filtered to obtain crystals, and dried at 40 °C for 1 h to finally obtain 0.11 kg of TNOA crystals (3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane).
[0033] Figure 1 The image shows a liquid chromatogram of TNOA crystals (3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane) prepared by the method in Example 1. The purity of the crystals was characterized by high performance liquid chromatography (HPLC), which showed that the method of the present invention can efficiently prepare high-purity TNOA.
[0034] Figure 2 The image shows the DSC curve of TNOA crystals (3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane) prepared by the method in Example 1. The melting point was 219.8℃ by DSC characterization. The prepared TNOA showed a single sharp decomposition exothermic peak on the DSC curve, indicating that it has high purity.
[0035] Figure 3 and Figure 4 The figures show the 1H and 1C NMR spectra of TNOA crystals (3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane) prepared by the method in Example 1. As can be seen from the figures, each signal peak is consistent with the type and ratio of hydrogen and carbon atoms in its molecular structure, and no obvious impurity peaks are observed, indicating that the substance has high purity. Example 2
[0036] A method for preparing 3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane involves taking 10 kg of waste drug generated during the production of RDX via the acetic anhydride method, placing it in a stirred reactor, adding 50 kg of ethyl acetate and stirring to dissolve it for 30 min, filtering to remove insoluble matter, adding 200 kg of deionized water to the filtrate, and stirring for 30 min to obtain a mixture; transferring the mixture to an oil-water separator, allowing it to stand and separate into layers, separating the upper organic phase, placing the organic phase in an evaporator and evaporating it under a negative pressure of 0.09 MPa until it reaches 5.6 L, obtaining a concentrated solution.
[0037] Add 1.5 kg of chromatographic grade silica gel powder (300~400 mesh) to the concentrate, stir for 30 min, and air dry to obtain the mixed silica gel.
[0038] Take another 18.5 kg of chromatography-grade silica gel powder (300~400 mesh) and load it into... Φ In a 25cm×100cm chromatography column, pack the column and compact it, elute to equilibrium, spread the sample-mixed silica gel evenly on the top of the chromatography column, then place the filter cloth and sieve plate on top, and install the end cap.
[0039] First, elution was performed using organic solvent system A (eluent A), prepared with ethyl acetate and petroleum ether at a volume ratio of 30:70, for 32 column volumes (1130 L). Then, organic solvent system B (eluent B), prepared with ethyl acetate and petroleum ether at a volume ratio of 32:68, was used for another 3 column volumes (106 L). After elution, the eluent from organic solvent system B was collected. The entire elution process was monitored using an online UV detector. The target fraction collection program was started simultaneously when elution began with organic solvent system B: the target fraction was collected when a clear absorption peak appeared on the chromatogram and the peak shape stabilized. Collection was stopped when the absorption peak signal returned to the baseline, and 106 L of the target fraction eluent was finally obtained.
[0040] The collected effluent was evaporated to 10.6 L at an evaporation temperature of 40 °C, then cooled to room temperature, filtered to obtain crystals, and dried at 40 °C for 1 h to finally obtain 0.23 kg of TNOA crystals (3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane).
[0041] Its purity was 99.7% as determined by high performance liquid chromatography (HPLC), and its melting point was 219.8℃ as determined by DSC. Example 3
[0042] A method for preparing 3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane involves taking 10 kg of waste drug generated during the production of RDX via the acetic anhydride method, placing it in a stirred reactor, adding 100 kg of ethyl acetate and stirring to dissolve it for 30 min, filtering to remove insoluble matter, adding 300 kg of deionized water to the filtrate, and stirring for 30 min to obtain a mixture; transferring the mixture to an oil-water separator, allowing it to stand and separate into layers, separating the upper organic phase, placing the organic phase in an evaporator and evaporating it under a negative pressure of 0.09 MPa until 11 L is obtained as a concentrated solution.
[0043] Add 1.5 kg of chromatographic grade silica gel powder (300~400 mesh) to the concentrate, stir for 30 min, and air dry to obtain the mixed silica gel.
[0044] Take another 18.5 kg of chromatography-grade silica gel powder (300~400 mesh) and load it into... Φ In a 25cm×100cm chromatography column, pack the column and compact it, elute to equilibrium, spread the sample-mixed silica gel evenly on the top of the chromatography column, then place the filter cloth and sieve plate on top, and install the end cap.
[0045] First, elution was performed using organic solvent system A (eluent A), prepared with ethyl acetate and petroleum ether at a volume ratio of 30:70, for 32 column volumes (1130 L). Then, organic solvent system B (eluent B), prepared with ethyl acetate and petroleum ether at a volume ratio of 35:65, was used for elution for another 5 column volumes (141 L). After elution, the eluent from organic solvent system B was collected. The entire elution process was monitored using an online UV detector. The target fraction collection program was started simultaneously when elution began with organic solvent system B: the target fraction was collected when a clear absorption peak appeared on the chromatogram and the peak shape stabilized. Collection was stopped when the absorption peak signal returned to the baseline, and 177 L of the target fraction eluent was finally obtained.
[0046] The collected effluent was evaporated to 17.7 L at an evaporation temperature of 40 °C, then cooled to room temperature, filtered to obtain crystals, and dried at 40 °C for 1 h to finally obtain 0.25 kg of TNOA crystals (3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane).
[0047] Its purity was 99.7% as determined by high performance liquid chromatography (HPLC), and its melting point was 219.8℃ as determined by DSC.
[0048] The above description is merely an embodiment of this application, and the scope of protection of this application is not limited to these specific embodiments, but is determined by the claims of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the technical concept and principles of this application should be included within the scope of protection of this application.
Claims
1. A method for preparing 3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane, characterized in that, The preparation method using column chromatography includes the following steps: (1) Take the waste drug generated during the preparation of RDX by acetic anhydride and place it in a stirred reactor. Add organic solvent, stir to dissolve, filter to remove insoluble matter, and obtain filtrate. Add deionized water to the obtained filtrate and stir evenly to obtain a mixture. Transfer the mixture to an oil-water separator, let it stand and separate into layers, and separate the upper organic phase from the upper part of the oil-water separator. Evaporate the organic phase under a negative pressure of 0.09 MPa and concentrate it to 1 / 10 of the original volume to obtain a concentrated solution. (2) Add chromatographic grade silica gel powder to the concentrated solution obtained in step (1), stir evenly, and dry to obtain sample-mixed silica gel; (3) Take another chromatographic grade silica gel powder and pack it into the chromatography column. Pack the column and compact it. Spread the mixed silica gel obtained in step (2) evenly on the top of the chromatography column as a sample. Then put on filter cloth and sieve plate and install the end cap. (4) Prepare two elution systems with different ratios, namely organic solvent system A and organic solvent system B. Organic solvent system A is ethyl acetate and petroleum ether in a volume ratio of 30:70, and organic solvent system B is ethyl acetate and petroleum ether in a volume ratio of 31:69~35:
65. First, use organic solvent system A to elute the chromatography column, and then switch to organic solvent system B to continue eluting. Collect the eluent from organic solvent system B. (5) Evaporation crystallization is used to evaporate the effluent collected in step (4), then cool it to room temperature, filter it, and dry it to obtain TNOA crystals, which are the 3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane.
2. The method for preparing 3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane according to claim 1, characterized in that: In step (1), the organic solvent is ethyl acetate, the mass of ethyl acetate added is 5 to 10 times the mass of the waste drug, and the stirring and dissolving time is 30 min.
3. The method for preparing 3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane according to claim 1, characterized in that: In step (1), the mass of deionized water added is 3 to 4 times the mass of the organic solvent, and the stirring time is 30 min.
4. The method for preparing 3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane according to claim 1, characterized in that: In step (2), the mass of chromatographic grade silica gel powder added is 0.1 to 0.3 times the mass of waste drug, and the stirring time during the sample mixing process is 30 minutes.
5. The method for preparing 3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane according to claim 1, characterized in that: In step (3), the amount of chromatographic grade silica powder added is the capacity of the chromatography column minus the amount of silica powder added for mixing the sample.
6. The method for preparing 3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane according to claim 1, characterized in that: In steps (2) and (3), the particle size of the chromatographic grade silica gel powder is 300~400 mesh.
7. The method for preparing 3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane according to claim 1, characterized in that: In step (4), 29 to 32 column volumes of organic solvent system A are used for elution, and 3 to 5 column volumes of organic solvent system B are used for elution.
8. The method for preparing 3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane according to claim 7, characterized in that: In step (4), the elution process uses an online ultraviolet detector to monitor the effluent.
9. The method for preparing 3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane according to claim 8, characterized in that: In step (4), the effluent eluted from organic solvent system B is the target fraction. The detection wavelength is set to 254 nm. The system is qualified if the baseline is stable and there are no obvious impurity peaks. During the elution process, when an obvious absorption peak appears and the peak shape is stable, the target fraction is collected. When the absorption peak signal drops to the baseline, the collection is stopped.
10. The method for preparing 3,5,7-trinitro-1-oxo-3,5,7-triazacyclooctane according to claim 1, characterized in that: In step (5), the evaporation temperature is 40°C, and the collected effluent is evaporated to 1 / 10 of its original volume; the drying temperature is 40°C, and the drying time is 1 hour.