High energy density materials based on 5,6-fused triazole triazine and nitropyrazole-tetrazolyl composites

Abstract

The present invention discloses a high energy density material composed of a 5,6-fused triazole triazine and a nitropyrazole tetrazole. The high energy density material is 3-(1H-tetrazol-5-yl)-7-(4-nitro-1H-pyrazol-3-yl)-[1,2,4]triazol-5-yl[5,1-c][1,2,4]triazine-4-amino, and has a structural formula of 3-(4,5-dinitro-1H-pyrazol-3-yl)-1H-1,2,4-triazol-5-amine and malononitrile to form an intermediate 4-amino-7-(4,5-dinitro-1H-pyrazol-3-yl)-[1,2,4]triazol-5,1-c][1,2,4]triazine-3-carbonitrile, which is then synthesized by a ring-closing reaction with sodium azide. The TDPTTA of the present invention has a p value of 1.87 g cm ‑3 , D = 8799 m s ‑1 , T d =203℃, IS>40J, and its comprehensive performance is better than RDX.

Description

Technical Field

[0001] The present invention belongs to the field of energetic materials and relates to a high energy density material composed of a 5,6-fused triazole triazine and a nitropyrazole-tetrazolyl composite. Background Art

[0002] In the design of modern energetic materials, the construction of fused ring frameworks is an effective strategy for improving the performance of novel high-energy-density compounds. Due to their unique cage-like or multi-ring coplanar structures and conjugated systems, fused ring compounds exhibit positive heats of formation, high density, and excellent stability. This is particularly true for fused ring explosives based on the 1,2,4-triazine framework, where adjacent amino and tetrazole rings on the fused rings stabilize the molecular structure of these energetic compounds through intramolecular and intermolecular hydrogen bonding.

[0003]

[0004] However, existing energetic compounds based on 5-amine-1,2,4-triazine and tetrazole energetic frameworks have drawbacks. For example, compound I (Cheng, Z.; Zhang, Z.; Ma, Q.; et al. A potential insensitive-highly-energetic material through conjugation-promoted N-oxidation strategy. Chem. Eng. J. 2021, 131990.) and compound II (Q. Wang, Y. Shao, M. Lu, Amino-tetrazole functionalized fused triazolotriazine and tetrazolo-triazine energetic materials, Chem. Commun. 2019, 55, 6062-6065.) have high density and detonation performance, but poor thermal stability (Td: 174°C (I), 181°C (II)). 3-Nitro-6-(1H-tetrazol-5-yl)-[1,2,3]triazolo[5,1-c][1,2,4]triazin-7-amine (Ⅲ) (S.Feng, P.Yin, C.He, S.Pang, and Jean'ne M.Shreeve, Tunable Dimroth 24 rearrangement of versatile 1,2,3-triazoles towards high-performance energetic materials, J.Mater.Chem.A.2021, 9, 12291-12298.) has a high sensitivity (IS:5J), but it is different from 6-(1H-tetrazol-5-yl)tetrazo[5,1-c][1,2,4]triazin-7-amine (Ⅳ) (Q.Wang, Y.Shao, M.Lu, Amino-tetrazole functionalized fused triazolotriazine and tetrazoline energetic materials, Chem. Commun. 2019, 55, 6062-6065.) have low energy densities (ρ: 1.77 g cm -3 , 1.795 g cm -3 ). Their poor stability and low energy density cannot meet the increasing demand for practical applications. Summary of the Invention

[0005] The present invention provides a high energy density material composed of 5,6-fused triazole triazine and nitropyrazole-tetrazole.

[0006] The high energy density material of the 5,6-fused triazole triazine and nitropyrazole-tetrazole composite of the present invention is 3-(1H-tetrazol-5-yl)-7-(4-nitro-1H-pyrazol-3-yl)-[1,2,4]triazolyl[5,1-c][1,2,4]triazine-4-amino (TDPTTA), and has the following structural formula:

[0007]

[0008] The present invention also provides a method for synthesizing the high-energy density material of the 5,6-fused triazole triazine and nitropyrazole-tetrazole composite, wherein 3-(4,5-dinitro-1H-pyrazol-3-yl)-1H-1,2,4-triazol-5-amine (1) is used as a raw material, and a ring-closure reaction is carried out with malononitrile to produce an intermediate 4-amino-7-(4,5-dinitro-1H-pyrazol-3-yl)-[1,2,4]triazole[5,1-c][1,2,4]triazine-3-carbonitrile (2), and the intermediate is then subjected to a ring-closure reaction with sodium azide to synthesize the target product TDPTTA. The synthesis route is as follows:

[0009]

[0010] The specific steps are as follows:

[0011] Step 1: slowly adding 3-(4,5-dinitro-1H-pyrazol-3-yl)-1H-1,2,4-triazol-5-amine to a mixture of concentrated hydrochloric acid and water, then adding a sodium nitrite solution at 0-5°C, stirring at 0-5°C until uniformly mixed, adding a mixed solution of malononitrile and sodium acetate dropwise to the reaction system, stirring at -2°C, then raising the temperature to 30±5°C and reacting for more than 12 hours. After the reaction is completed, the precipitate is filtered, washed with water and ethanol, and dried in air to obtain 4-amino-7-(4,5-dinitro-1H-pyrazol-3-yl)-[1,2,4]triazolo[5,1-c][1,2,4]triazine-3-carbonitrile;

[0012] Step 2, adding 4-amino-7-(4,5-dinitro-1H-pyrazol-3-yl)-[1,2,4]triazolo[5,1-c][1,2,4]triazine-3-carbonitrile and NaN3 to a solvent, heating to 105±10°C for reaction for more than 12 hours, and concentrating after the reaction to remove excess solvent, and then precipitating with sodium chloride solution, filtering the precipitate, washing with water and ethanol, and drying in air to obtain TDPTTA.

[0013] Preferably, in step 1, the concentration of the concentrated hydrochloric acid is 37 wt %.

[0014] Preferably, in step 1, in the mixture of concentrated hydrochloric acid and water, the volume ratio of hydrochloric acid to water is 1:2 to 5, more preferably 3:10.

[0015] Preferably, in step 1, the mass ratio of sodium nitrite to concentrated hydrochloric acid is 1:2 to 1:4, g:mL.

[0016] Preferably, in step 1, the molar ratio of 3-(4,5-dinitro-1H-pyrazol-3-yl)-1H-1,2,4-triazole-5-amine to malononitrile is 1:1.

[0017] Preferably, in step 1, the reaction time is 12 to 36 hours.

[0018] Preferably, in step 2, the solvent is selected from water, N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), a DMF\DMSO mixed solvent with a volume ratio of 1:0.5~2, a DMF\water mixed solvent with a volume ratio of 1:0.5~2, or a DMSO\water mixed solvent with a volume ratio of 1:0.5~2.

[0019] Preferably, in step 2, the molar ratio of 4-amino-7-(4,5-dinitro-1H-pyrazol-3-yl)-[1,2,4]triazolo[5,1-c][1,2,4]triazine-3-carbonitrile and NaN3 is 1:0.8-2.

[0020] Preferably, in step 2, the reaction time is 12 to 48 hours.

[0021] Preferably, in step 2, the concentration of the sodium chloride solution is 0.1±0.05 g / L.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] (1) The present invention selects a high-nitrogen-content polynitropyrazole-1,2,4-triazole ring as the basic skeleton, introduces a high-energy triazine ring, and introduces a high-energy explosive tetrazole ring to increase the energy of the linked ring skeleton. The obtained TDPTTA has a ρ of 1.87 g / cm -3 , D = 8799 m s -1 , T d＝ 203℃, IS>40J, comprehensive performance is better than RDX.

[0024] (2) The first step of the synthesis method of the present invention is cyclization to form a triazole-triazine fused ring, and the second step is cyclization with sodium azide to form a tetrazole ring. The two-step cyclization method is used to synthesize the fused ring compound TDPTTA, which has the advantages of short reaction steps and high yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1is the H NMR spectrum of TDPTTA;

[0026] Figure 2 is the C NMR spectrum of TDPTTA;

[0027] Figure 3 This is a single crystal image of TDPTTA. DETAILED DESCRIPTION

[0028] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0029] Example 1

[0030] 3-(4,5-dinitro-1H-pyrazol-3-yl)-1H-1,2,4-triazole-5-amine (2.40 g, 10.0 mmol) was slowly added to a mixture of 3 ml of concentrated hydrochloric acid (37 wt.%) and 10 ml of water. Sodium nitrite (0.80 g, 11.6 mmol) was then added to the mixture at 0 ° C. After stirring for 1 h at 0 ° C, a solution of malononitrile (0.49 g, 10.0 mmol) and sodium acetate (3.97 g, 11.7 mmol) dissolved in 12 ml of water was added dropwise to the reaction system. The reaction system was stirred at -2 ° C for 2 h and then raised to 30 ° C for overnight reaction. The precipitate was filtered, washed with water and ethanol, and dried in air to give 4-amino-7-(4,5-dinitro-1H-pyrazol-3-yl)-[1,2,4]triazolo[5,1-c][1,2,4]triazine-3-carbonitrile (2.40, 77.8%).

[0031] 4-Amino-7-(4,5-dinitro-1H-pyrazol-3-yl)-[1,2,4]triazolo[5,1-c][1,2,4]triazine-3-carbonitrile (1.56 g, 5.0 mmol) and 0.34 g NaN3 were suspended in 30 ml N,N-dimethylformamide (DMF). The solution was heated to 105°C and reacted for 12 hours. The solution was concentrated in vacuo to remove excess solvent and then diluted with 0.1 g / L sodium chloride solution until no more precipitate formed. The precipitate was filtered, washed with water and ethanol, and dried in air to obtain TDPTTA as a brown-black solid with a yield of 3.24 g, 90.6%.

[0032] 1 H NMR (500MHz, DMSO-d6): 7.55(s), 8.95(s), 10.05(s), 10.21(s)ppm. 13C NMR(125MHz, DMSO-d6): δ120.9,127.3,133.4,140.9,148.2,152.6,156.2,156.4ppm.IR(KBr):3653,3562,3205,2985 ,2987,2904,2141,1644,1557,1476,1399,1393,1340,1238,1193,1106,1018,944,902,850,759,679,644,580,490cm -1 .Elemental analysis for C8H4N 14 O4(360.21):calcd.C 26.28,H 1.12,N 54.44%.Found:C 26.30,H 1.15,N 54.39%.

[0033] Example 2

[0034] 3-(4,5-dinitro-1H-pyrazol-3-yl)-1H-1,2,4-triazole-5-amine (2.40 g, 10.0 mmol) was slowly added to a mixture of 3 ml of concentrated hydrochloric acid (37 wt.%) and 10 ml of water. Sodium nitrite (0.80 g, 11.6 mmol) was then added to the mixture at 0 ° C. After stirring for 1 h at 0 ° C, a solution of malononitrile (0.66 g, 13.5 mmol) and sodium acetate (3.97 g, 11.7 mmol) dissolved in 12 ml of water was added dropwise to the reaction system. The reaction system was stirred at -2 ° C for 2 h and then raised to 25 ° C for overnight reaction. The precipitate was filtered, washed with water and ethanol, and dried in air to give 4-amino-7-(4,5-dinitro-1H-pyrazol-3-yl)-[1,2,4]triazolo[5,1-c][1,2,4]triazine-3-carbonitrile (1.30 g, 42.1%).

[0035] 4-Amino-7-(4,5-dinitro-1H-pyrazol-3-yl)-[1,2,4]triazolo[5,1-c][1,2,4]triazine-3-carbonitrile (1.56 g, 5.0 mmol) and 0.34 g NaN3 were suspended in 30 ml N,N-dimethylformamide (DMF). The solution was heated to 105°C and reacted for 15 hours. The solution was concentrated in vacuo to remove excess solvent and then diluted with 0.1 g / L sodium chloride until no more precipitate formed. The precipitate was filtered, washed with water and ethanol, and dried in air to obtain TDPTTA as a brown-black solid with a yield of 2.01 g, 55.4%.

[0036] Example 3

[0037] 3-(4,5-dinitro-1H-pyrazol-3-yl)-1H-1,2,4-triazole-5-amine (2.40 g, 10.0 mmol) was slowly added to a mixture of 3 ml of concentrated hydrochloric acid (37 wt.%) and 8 ml of water. Sodium nitrite (0.90 g, 5.08 mmol) was then added to the mixture at 0 ° C. After stirring for 1 h at 0 ° C, a solution of malononitrile (0.60 g, 60 mmol) and sodium acetate (3.97 g, 11.7 mmol) dissolved in 12 ml of water was added dropwise to the reaction system. The reaction system was stirred at -2 ° C for 2 h and then raised to 30 ° C for overnight reaction. The precipitate was filtered, washed with water and ethanol, and dried in air to give 4-amino-7-(4,5-dinitro-1H-pyrazol-3-yl)-[1,2,4]triazolo[5,1-c][1,2,4]triazine-3-carbonitrile (1.04 g, 33.7%).

[0038] 4-Amino-7-(4,5-dinitro-1H-pyrazol-3-yl)-[1,2,4]triazolo[5,1-c][1,2,4]triazine-3-carbonitrile (1.56 g, 5.0 mmol) and 0.34 g of NaN3 were suspended in 30 ml of N,N-dimethylformamide (DMF). The solution was heated to 105°C and reacted for 24 hours. The solution was concentrated in vacuo to remove excess solvent and then diluted with 0.15 g / L sodium chloride until no more precipitate formed. The precipitate was filtered, washed with water and ethanol, and air-dried to obtain TDPTTA as a brown-black solid in a yield of 2.20 g, 63.6%.

[0039] Example 4

[0040] 3-(4,5-dinitro-1H-pyrazol-3-yl)-1H-1,2,4-triazole-5-amine (2.40 g, 10.0 mmol) was slowly added to a mixture of 3 ml of concentrated hydrochloric acid (37 wt.%) and 10 ml of water. Sodium nitrite (0.80 g, 11.6 mmol) was then added to the mixture at 0 ° C. After stirring for 1 h at 0 ° C, a solution of malononitrile (0.49 g, 10.0 mmol) and sodium acetate (3.97 g, 11.7 mmol) dissolved in 12 ml of water was added dropwise to the reaction system. The reaction system was stirred at -2 ° C for 2 h and then raised to 30 ° C for overnight reaction. The precipitate was filtered, washed with water and ethanol, and dried in air to give 4-amino-7-(4,5-dinitro-1H-pyrazol-3-yl)-[1,2,4]triazolo[5,1-c][1,2,4]triazine-3-carbonitrile (2.40, 77.8%).

[0041] 4-Amino-7-(4,5-dinitro-1H-pyrazol-3-yl)-[1,2,4]triazolo[5,1-c][1,2,4]triazine-3-carbonitrile (1.56 g, 5.0 mmol) and 0.20 g of NaN3 were suspended in 30 ml of dimethyl sulfoxide (DMSO). The solution was heated to 95°C and reacted for 13 hours. The solution was concentrated in vacuo to remove excess solvent and then diluted with 0.01 g / L sodium chloride until no more precipitate formed. The precipitate was filtered, washed with water and ethanol, and air-dried to obtain TDPTTA as a brown-black solid in a yield of 2.08 g, 62.2%.

[0042] Example 5

[0043] 3-(4,5-dinitro-1H-pyrazol-3-yl)-1H-1,2,4-triazole-5-amine (2.40 g, 10.0 mmol) was slowly added to a mixture of 3 ml of concentrated hydrochloric acid (37 wt.%) and 10 ml of water. Sodium nitrite (0.80 g, 11.6 mmol) was then added to the mixture at 0 ° C. After stirring for 1 h at 0 ° C, a solution of malononitrile (0.49 g, 10.0 mmol) and sodium acetate (3.97 g, 11.7 mmol) dissolved in 12 ml of water was added dropwise to the reaction system. The reaction system was stirred at -2 ° C for 2 h and then raised to 30 ° C for overnight reaction. The precipitate was filtered, washed with water and ethanol, and dried in air to give 4-amino-7-(4,5-dinitro-1H-pyrazol-3-yl)-[1,2,4]triazolo[5,1-c][1,2,4]triazine-3-carbonitrile (2.40, 77.8%).

[0044] 4-Amino-7-(4,5-dinitro-1H-pyrazol-3-yl)-[1,2,4]triazolo[5,1-c][1,2,4]triazine-3-carbonitrile (1.56 g, 5.0 mmol) and 0.34 g of NaN3 were suspended in 15 ml of N,N-dimethylformamide (DMF) and 15 ml of dimethyl sulfoxide (DMSO). The solution was heated to 105°C and reacted for 21 hours. The solution was concentrated in vacuo to remove excess solvent and then diluted with 0.1 g / L sodium chloride until no more precipitate formed. The precipitate was filtered, washed with water and ethanol, and air-dried to obtain TDPTTA as a brown-black solid in a yield of 1.98 g, 59.4%.

[0045] Example 6

[0046] 3-(4,5-dinitro-1H-pyrazol-3-yl)-1H-1,2,4-triazole-5-amine (2.40 g, 10.0 mmol) was slowly added to a mixture of 3 ml of concentrated hydrochloric acid (37 wt.%) and 10 ml of water. Sodium nitrite (0.80 g, 11.6 mmol) was then added to the mixture at 0 ° C. After stirring for 1 h at 0 ° C, a solution of malononitrile (0.49 g, 10.0 mmol) and sodium acetate (3.97 g, 11.7 mmol) dissolved in 12 ml of water was added dropwise to the reaction system. The reaction system was stirred at -2 ° C for 2 h and then raised to 30 ° C for overnight reaction. The precipitate was filtered, washed with water and ethanol, and dried in air to give 4-amino-7-(4,5-dinitro-1H-pyrazol-3-yl)-[1,2,4]triazolo[5,1-c][1,2,4]triazine-3-carbonitrile (2.40, 77.8%).

[0047] 4-Amino-7-(4,5-dinitro-1H-pyrazol-3-yl)-[1,2,4]triazolo[5,1-c][1,2,4]triazine-3-carbonitrile (1.56 g, 5.0 mmol) and 0.34 g of NaN3 were suspended in 15 ml of N,N-dimethylformamide (DMF) and 15 ml of water. The solution was heated to 90°C and reacted for 14 hours. The solution was concentrated in vacuo to remove excess solvent and then diluted with 0.1 g / L sodium chloride until no more precipitate formed. The precipitate was filtered, washed with water and ethanol, and air-dried to obtain TDPTTA as a brown-black solid in a yield of 1.50 g, 45.5%.

Claims

1. A high energy density material composed of 5,6-fused triazole triazine and nitropyrazole-tetrazole, which is 3-(1H-tetrazol-5-yl)-7-(4-nitro-1H-pyrazol-3-yl)-[1,2,4]triazolyl[5,1-c][1,2,4]triazine-4-amino, with the structural formula 。 2. The method for synthesizing a high energy density material according to claim 1, wherein: The specific steps are as follows: Step 1: slowly adding 3-(4,5-dinitro-1H-pyrazol-3-yl)-1H-1,2,4-triazol-5-amine to a mixture of concentrated hydrochloric acid and water, then adding a sodium nitrite solution at 0-5°C, stirring at 0-5°C until uniformly mixed, adding a mixed solution of malononitrile and sodium acetate dropwise to the reaction system, stirring at -2°C, then raising the temperature to 30±5°C for reaction for more than 12 hours, filtering the precipitate after completion of the reaction, washing with water and ethanol, and drying in air to obtain 4-amino-7-(4,5-dinitro-1H-pyrazol-3-yl)-[1,2,4]triazolo[5,1-c][1,2,4]triazine-3-carbonitrile; Step 2: Add 4-amino-7-(4,5-dinitro-1H-pyrazol-3-yl)-[1,2,4]triazolo[5,1-c][1,2,4]triazine-3-carbonitrile and NaN3 to a solvent, heat to 105±10°C and react for more than 12 hours. After the reaction, concentrate to remove excess solvent, then precipitate with sodium chloride solution, filter the precipitate, wash with water and ethanol, and dry in air to obtain 3-(1H-tetrazol-5-yl)-7-(4-nitro-1H-pyrazol-3-yl)-[1,2,4]triazolo[5,1-c][1,2,4]triazine-4-amino.

3. The synthesis method according to claim 2, characterized in that In step 1, the concentration of the concentrated hydrochloric acid is 37wt%; in the mixture of concentrated hydrochloric acid and water, the volume ratio of hydrochloric acid to water is 1:2~5.

4. The synthesis method according to claim 2, characterized in that In step 1, in the mixture of concentrated hydrochloric acid and water, the volume ratio of hydrochloric acid to water is 3:

10.

5. The synthesis method according to claim 2, characterized in that In step 1, the mass ratio of sodium nitrite to concentrated hydrochloric acid is 1:2 to 1:4, g:mL.

6. The synthesis method according to claim 2, characterized in that In step 1, the molar ratio of 3-(4,5-dinitro-1H-pyrazol-3-yl)-1H-1,2,4-triazol-5-amine and malononitrile is 1:

1.

7. The synthesis method according to claim 2, wherein In step 1, the reaction time is 12 to 36 hours.

8. The synthesis method according to claim 2, characterized in that In step 2, the solvent is selected from water, DMF, DMSO, a DMF\DMSO mixed solvent with a volume ratio of 1:0.5~2, a DMF\water mixed solvent with a volume ratio of 1:0.5~2, or a DMSO\water mixed solvent with a volume ratio of 1:0.5~2.

9. The synthesis method according to claim 2, characterized in that In step 2, the molar ratio of 4-amino-7-(4,5-dinitro-1H-pyrazol-3-yl)-[1,2,4]triazolo[5,1-c][1,2,4]triazine-3-carbonitrile and NaN3 is 1:0.8~2.

10. The synthesis method according to claim 2, characterized in that In step 2, the reaction time is 12 to 48 hours.

11. The synthesis method according to claim 2, characterized in that In step 2, the concentration of the sodium chloride solution is 0.1±0.05 g / L.

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