A method for preparing a high-energy, low-sensitivity fused-ring energetic compound
By synthesizing fused-ring energetic compounds through hydrolysis, decarboxylation, and nitration reactions, the safety risks associated with the use of nitroacetonitrile are resolved, and a high-efficiency, low-cost synthetic route is achieved, which is suitable for large-scale production and engineering applications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SOUTHWEAT UNIV OF SCI & TECH
- Filing Date
- 2023-12-22
- Publication Date
- 2026-07-17
AI Technical Summary
Existing technologies for synthesizing high-energy, low-sensitivity fused-ring energetic compounds use nitroacetonitrile, which has poor thermal stability and high sensitivity, resulting in high process risks and limiting scale-up and engineering applications.
Using inexpensive and readily available compound 1 as a raw material, the synthesis route is simplified by avoiding the use of nitroacetonitrile through hydrolysis, decarboxylation, and nitration reactions. Common and readily available hydrolysis and nitration systems and solvents are also used.
It enables the high-yield and low-cost synthesis of fused-ring energetic compounds, reduces the safety risks of the synthesis process, and is suitable for scale-up production and engineering applications.
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Figure CN117800974B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of energetic materials technology, specifically relating to a method for preparing a high-energy, low-sensitivity fused-ring energetic compound. Background Technology
[0002] Polynitrogen fused heterocycles are a class of energetic materials with advantages such as high enthalpy of formation, low mechanical sensitivity, good heat resistance, excellent detonation performance, and green and environmentally friendly detonation products. They have promising application prospects and have become one of the important research directions for high-energy, low-sensitivity energetic materials.
[0003] The fused-ring energetic compound shown in structural formula (I) is a high-energy, low-sensitivity energetic compound with excellent overall performance, VD = 8895 m / s, P = 35.4 GPa, IS > 60 J, FS > 360 N.
[0004] (I).
[0005] In existing technologies, this fused-ring energetic compound is mainly synthesized from 5-aminopyrazole via diazotization, cyclization, and nitration (see: Shi H, Wang Y, Wang X, et al. Concise Synthesis of A FusedEnergetic Pyrazolotriazine with Good Performances[J]. New Journal of Chemistry, 2024. DOI: 10.1039 / d3nj04391f). However, this synthetic route uses nitroacetonitrile, which has poor thermal stability and high sensitivity, making the process quite dangerous and limiting its scale-up and engineering applications. Summary of the Invention
[0006] This invention addresses the problems existing in the prior art by providing a method for preparing high-energy, low-sensitivity fused-ring energetic compounds. Using readily available and inexpensive compound (II) as a raw material, this invention synthesizes the fused-ring energetic compound (I) in high yield and at low cost through hydrolysis, decarboxylation, and nitration reactions. This route avoids the use of nitroacetonitrile and the handling of energetic intermediates, solves the problem of high safety risks in the synthesis process, and facilitates scale-up production and engineering applications.
[0007] The technical solution adopted in this invention is:
[0008] A method for preparing a high-energy, low-sensitivity fused-ring energetic compound, the structural formula of which is as follows:
[0009] (I);
[0010] The method for preparing the fused-ring energetic compound shown in structural formula (I) includes the following steps:
[0011] Step S1: Place compound one in a hydrolysis system and hydrolyze to obtain compound two;
[0012] The structural formula of compound one is as follows:
[0013] (II);
[0014] The structural formula of compound two is as follows:
[0015] (III);
[0016] Step S2: Compound 2 is placed in a high-boiling-point solvent and heated to decarboxylate, yielding compound 3;
[0017] Among them, the boiling point of high-boiling solvents is greater than or equal to 80℃;
[0018] The structural formula of compound three is as follows:
[0019] (IV);
[0020] Step S3: Place compound tris in a nitration system and nitrate to obtain the fused-ring energetic compound shown in structural formula (I).
[0021] Furthermore, in step S1, the hydrolysis system is an acid hydrolysis system or an alkaline hydrolysis system.
[0022] Furthermore, the acid hydrolysis system includes aqueous solutions of sulfuric acid, hydrochloric acid, and phosphoric acid, as well as combinations thereof;
[0023] Alkaline hydrolysis systems include aqueous solutions of sodium hydroxide, potassium hydroxide, and lithium hydroxide, as well as combinations thereof.
[0024] Further, in step S2, the high-boiling-point solvent is N,N-dimethylformamide, N,N-dimethylacetamide, benzonitrile, xylene, N,N-dimethylaniline, nitrobenzene, or combinations thereof.
[0025] Furthermore, in step S2, the temperature for heating and decarboxylation is 80~200℃, and the reaction time is 1~100h.
[0026] Furthermore, the temperature for decarboxylation by heating is 120~160℃.
[0027] Furthermore, the reaction time for decarboxylation by heating is 8 to 30 hours.
[0028] Furthermore, in step S3, the nitration system is nitric acid, a nitrate / sulfuric acid composite system, a nitric acid / sulfuric acid composite system, or a nitric acid / acetic anhydride composite system.
[0029] Furthermore, the nitration system is a sodium nitrate / sulfuric acid composite system, and the mass ratio of sodium nitrate to concentrated sulfuric acid is 1:2.5-1:10.
[0030] Furthermore, in step S3, the temperature during nitration is 0–30°C.
[0031] The beneficial effects of this invention are:
[0032] 1. This invention uses the readily available and inexpensive compound (II) as a raw material to synthesize the fused-ring energetic compound (I) in high yield and at low cost through hydrolysis, decarboxylation, and nitration reactions. This route avoids the use of nitroacetonitrile and the handling of energetic intermediates, solves the problem of high safety risks in the synthesis process, and is conducive to scale-up production and engineering applications.
[0033] 2. The raw materials used in the entire reaction process of this invention are common and readily available, and the cost is not high. The equipment required is also relatively simple, without the need for special devices. The reaction steps are simple overall, and the post-processing of the product is relatively simple, consisting of common operating steps. Furthermore, the intermediates do not contain energy. Attached Figure Description
[0034] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0035] Figure 1 For the fused-ring energetic compound shown in structural formula (I) 1 H NMR spectrum.
[0036] Figure 2 For the fused-ring energetic compound shown in structural formula (I) 13 C NMR spectrum.
[0037] Figure 3 The diagram shows the single-crystal structure of the fused-ring energetic compound represented by structural formula (I). Detailed Implementation
[0038] The embodiments of the invention will now be described in detail with reference to the accompanying drawings.
[0039] A method for preparing a high-energy, low-sensitivity fused-ring energetic compound includes the following steps:
[0040] Step S1: Place compound one in a hydrolysis system and hydrolyze to obtain compound two;
[0041] The structural formula of compound one is as follows:
[0042] (II);
[0043] The structural formula of compound two is as follows:
[0044] (III).
[0045] Specifically, compound one can be synthesized by referring to the route described in the literature (see: Novinson T, Okabe T, Robins RK, et al. Synthesis and antimicrobial activity of some novelheterocycles. Azolo-as-triazines[J]. Journal of Medicinal Chemistry, 1976, 19(4): 517-520.).
[0046] Compound 1 was dissolved in a hydrolysis system, heated to reflux, and the reaction was monitored by TLC until it was completed. The mixture was then cooled to room temperature, ice water was added, the precipitate was filtered, washed with water, and dried to obtain compound 2.
[0047] The hydrolysis system can be either an acidic or alkaline system. Preferably, the acidic hydrolysis system includes aqueous solutions of sulfuric acid, hydrochloric acid, and phosphoric acid, or combinations thereof. When using an acidic hydrolysis system, the reaction is carried out under reflux. After TLC detection of the reaction completion, the system is cooled to room temperature, the precipitate is filtered, and then dried. Preferably, the alkaline hydrolysis system includes aqueous solutions of sodium hydroxide, potassium hydroxide, and lithium hydroxide, or combinations thereof. When using an alkaline hydrolysis system, the reaction is carried out under reflux. After TLC detection of the reaction completion, the system is cooled to room temperature, acidified to pH 3, the precipitate is filtered, and then dried.
[0048] Step S2: Compound 2 is placed in a high-boiling-point solvent and heated to decarboxylate, yielding compound 3;
[0049] Among them, the boiling point of high-boiling solvents is greater than or equal to 80℃;
[0050] The structural formula of compound three is as follows:
[0051] (IV).
[0052] Specifically, compound 2 was placed in a high-boiling-point solvent with a boiling point greater than or equal to 80°C, and slowly heated under reflux. After the reaction was confirmed to be complete by TLC, cold water was added, and the mixture was extracted three times with EA. Compound 3 was obtained by vacuum distillation.
[0053] The high-boiling-point solvent is N,N-dimethylformamide, N,N-dimethylacetamide, benzonitrile, xylene, N,N-dimethylaniline, nitrobenzene, or combinations thereof. The temperature for decarboxylation by heating is 80~200℃, preferably 120~160℃; the reaction time is 1~100h, preferably 8~30h.
[0054] Step S3: Compound tris is placed in a nitration system and nitrated to obtain a fused-ring energetic compound, the structural formula of which is as follows:
[0055] (I).
[0056] Specifically, at low temperatures, such as 0–30°C, the compound was added to the nitration system in three batches. After the addition was complete, the temperature was naturally raised to room temperature while the reaction was stirred. Once the reaction was complete, as detected by TLC, ice water was poured in, the precipitate was filtered, and dried to obtain the fused-ring energetic compound.
[0057] The nitration system can be a nitric acid system, a nitrate / sulfuric acid composite system, a nitric acid / sulfuric acid composite system, or a nitric acid / acetic anhydride composite system. Preferably, the nitration system is a sodium nitrate / sulfuric acid composite system, and the mass ratio of sodium nitrate to concentrated sulfuric acid is 1:2.5-1:10.
[0058] The following will illustrate this with more specific examples.
[0059] Example 1: Preparation of compound one shown in structural formula (II)
[0060] At 0–5 °C, 1.00 g (12.00 mmol) of 3-aminopyrazole was dissolved in 10 mL of concentrated hydrochloric acid, and an aqueous solution of 1.04 g (15.00 mmol) of sodium nitrite (10 mL) was slowly added. The reaction was maintained in an ice bath for 20 min, and then an aqueous solution of 1.00 g (15.00 mmol) of malononitrile and 4.92 g (60.00 mmol) of sodium acetate (30 mL) was added. The resulting suspension was stirred at 25 °C for 2 h, and the precipitated solid was filtered and dried to give 1.65 g of compound I, shown in structural formula (II), with a yield of 86.10%.
[0061] Example 2: Preparation of compound two shown in structural formula (III)
[0062] Compound 1 (1.60 g, 10.00 mmol) of structural formula (II) was placed in 30 mL of 10% hydrochloric acid aqueous solution. The mixture was heated to reflux, and the reaction was monitored by TLC until completion. The mixture was then cooled to room temperature, the precipitate was filtered, washed with water, and dried to give 1.36 g of compound 2 of structural formula (III), with a yield of 76.30%.
[0063] Example 3: Preparation of compound two shown in structural formula (Ⅲ)
[0064] Compound 1 (1.60 g, 10.00 mmol) of structural formula (II) was placed in 30 mL of 20% sodium hydroxide aqueous solution. The mixture was heated to reflux, and the reaction was monitored by TLC until completion. The mixture was then cooled to room temperature, acidified with concentrated hydrochloric acid to pH 3, filtered to remove the precipitate, washed with water, and dried to give 1.24 g of compound 2 of structural formula (III), with a yield of 69.20%.
[0065] Example 4: Preparation of compound three shown in structural formula (IV)
[0066] Compound 2 (1.00 g, 5.59 mmol) as shown in structural formula (III) was added to 12 mL of N,N-dimethylformamide (DMF), and the mixture was slowly heated to reflux and maintained under reflux for 10 h. The reaction was monitored by TLC until complete. After cooling to room temperature, the mixture was poured into cold water, extracted with EA (20 mL × 3), and evaporated to dryness to give 0.65 g of compound 3 (as shown in structural formula (IV)) as a gray solid, with a yield of 85.70%.
[0067] Example 5: Preparation of compound three shown in structural formula (IV)
[0068] Compound 2 (1.00 g, 5.59 mmol) as shown in structural formula (III) was added to 12 mL of N,N-dimethylacetamide, and the mixture was slowly heated to reflux and maintained under reflux for 10 h. The reaction was monitored by TLC until complete. After cooling to room temperature, the mixture was poured into cold water, extracted with EA (20 mL × 3), and evaporated to dryness to give 0.62 g of compound 3 (as shown in structural formula (IV)) as a gray solid, with a yield of 82.20%.
[0069] Example 6: Preparation of compound three shown in structural formula (IV)
[0070] Compound 2 (1.00 g, 5.59 mmol) as shown in structural formula (III) was added to 12 mL of N,N-dimethylaniline, and the mixture was slowly heated to reflux and maintained under reflux for 10 h. The reaction was monitored by TLC until complete. After cooling to room temperature, the mixture was poured into cold water, extracted with EA (20 mL × 3), and evaporated to dryness to give 0.70 g of compound 3 (as shown in structural formula (IV)) as a gray solid, with a yield of 87.90%.
[0071] Example 7: Preparation of the fused-ring energetic compound shown in structural formula (I)
[0072] Compound III (0.5 g, 3.70 mmol) of structural formula (IV) was added in portions to 4 mL of concentrated sulfuric acid at 0–5 °C. After compound III was completely dissolved, 3 mL of nitric acid was slowly added dropwise, with the temperature controlled between 0 and 30 °C. After the addition was complete, the mixture was allowed to warm to room temperature naturally while stirring continuously. After the reaction was completed as detected by TLC, ice water was poured in, the precipitate was filtered, washed with water, and dried to obtain 0.58 g of the fused-ring energetic compound of structural formula (I), with a yield of 69.20%.
[0073] Example 8: Preparation of the fused-ring energetic compound shown in structural formula (I)
[0074] Compound 3 (0.5 g, 3.70 mmol) of structural formula (IV) was added in portions to 4 mL of concentrated sulfuric acid at 0–5 °C. After compound 3 was completely dissolved, NaNO3 (1.70 g, 20.00 mmol) was added in portions, with the temperature controlled between 0 and 30 °C. After the addition was complete, the temperature was allowed to rise naturally to room temperature, and the reaction was stirred continuously. After the reaction was completed as detected by TLC, ice water was poured in, the precipitate was filtered, washed with water, and dried to obtain 0.53 g of the fused-ring energetic compound of structural formula (I), with a yield of 63.70%. The 1H and 1C NMR spectra of the fused-ring energetic compound of structural formula (I) are shown below. Figure 1 and Figure 2 As shown in the diagram. The single-crystal structure of the fused-ring energetic compound shown in structural formula (I) is as follows. Figure 3 As shown in the image.
[0075] In this embodiment, the readily available and inexpensive compound (II) is used as a starting material. Through hydrolysis, decarboxylation, and nitration, the fused-ring energetic compound (I) is synthesized in high yield and at low cost. This route avoids the use of nitroacetonitrile and the handling of energetic intermediates, solving the problem of high safety risks in the synthesis process and facilitating scale-up production and engineering applications. Furthermore, the raw materials used in this embodiment are common and readily available, with low costs. The required equipment is relatively simple, without the need for special devices. The overall reaction steps are also simple, and the post-processing of the product is relatively straightforward, involving common operational steps. Moreover, the intermediates are non-energized.
Claims
1. A method for preparing a high-energy, low-sensitivity fused-ring energetic compound, characterized in that, The structural formulas of the fused-ring energetic compounds are as follows: （I）； The method for preparing the fused-ring energetic compound shown in structural formula (I) includes the following steps: Step S1: Place compound one in a hydrolysis system and hydrolyze to obtain compound two; The structural formula of compound one is as follows: （Ⅱ）； The structural formula of compound two is as follows: （Ⅲ）； Step S2: Compound 2 is placed in a high-boiling-point solvent and heated to decarboxylate at a temperature of 80~200℃ to obtain compound 3; Among them, the boiling point of high-boiling solvents is greater than or equal to 80℃; The structural formula of compound three is as follows: （Ⅳ）； Step S3: Place compound tris in a nitration system and nitrate at a temperature of 0–30 °C to obtain the fused-ring energetic compound shown in structural formula (I).
2. The method for preparing the high-energy, low-sensitivity fused-ring energetic compound according to claim 1, characterized in that, In step S1, the hydrolysis system is either an acid hydrolysis system or an alkaline hydrolysis system.
3. The method for preparing the high-energy, low-sensitivity fused-ring energetic compound according to claim 2, characterized in that, Acid hydrolysis systems include aqueous solutions of sulfuric acid, hydrochloric acid, and phosphoric acid, as well as combinations thereof; Alkaline hydrolysis systems include aqueous solutions of sodium hydroxide, potassium hydroxide, and lithium hydroxide, as well as combinations thereof.
4. The method for preparing the high-energy, low-sensitivity fused-ring energetic compound according to claim 1, characterized in that, In step S2, the high-boiling-point solvent is N,N-dimethylformamide, N,N-dimethylacetamide, benzonitrile, xylene, N,N-dimethylaniline, nitrobenzene, or combinations thereof.
5. The method for preparing the high-energy, low-sensitivity fused-ring energetic compound according to claim 1 or 4, characterized in that, In step S2, the reaction time is 1~100h.
6. The method for preparing the high-energy, low-sensitivity fused-ring energetic compound according to claim 1, characterized in that, The temperature for decarboxylation by heating is 120~160℃.
7. The method for preparing the high-energy, low-sensitivity fused-ring energetic compound according to claim 5, characterized in that, The reaction time for decarboxylation by heating is 8 to 30 hours.
8. The method for preparing a high-energy, low-sensitivity fused-ring energetic compound according to any one of claims 1 to 4, 6 and 7, characterized in that, In step S3, the nitration system is nitric acid, a nitrate / sulfuric acid composite system, a nitric acid / sulfuric acid composite system, or a nitric acid / acetic anhydride composite system.
9. The method for preparing the high-energy, low-sensitivity fused-ring energetic compound according to claim 8, characterized in that, The nitration system is a sodium nitrate / sulfuric acid composite system, and the mass ratio of sodium nitrate to concentrated sulfuric acid is 1:2.5-1:10.