3,8-dinitro-7-(trinitromethyl)pyrazolo[5,1-c][1,2,4]triazin-4-amine and a method for its synthesis

Abstract

The application discloses 3,8-dinitro-7-(trinitromethyl)pyrazole[5,1-c][1,2,4]triazine-4-amine and a synthesis method thereof. The method takes 2-(3-amino-1H-pyrazol-5-yl) acetic acid as raw material, takes water as solvent, and is first reacted with sodium nitroacetonitrile to obtain a 5-6 fused ring intermediate, and then nitrates the fused ring intermediate by using nitric acid / sulfuric acid to obtain 3,8-dinitro-7-(trinitromethyl)pyrazole[5,1-c][1,2,4]triazine-4-amine. The synthesis method is simple and has high yield, 3,8-dinitro-7-(trinitromethyl)pyrazole[5,1-c][1,2,4]triazine-4-amine has high decomposition temperature, the initial decomposition temperature is 205 DEG C, the actual measured density is 1.947 g / cm 3 , the calculated detonation velocity is 9492 m / s, the calculated detonation pressure is 41.0 Gpa, the actual measured sensitivity is 192 J, 12 J, and the product has excellent comprehensive performance.

Description

Technical Field

[0001] This invention belongs to the field of energetic materials and relates to a 3,8-dinitro-7-(trinitromethyl)pyrazole[5,1-c][1,2,4]triazine-4-amine and its synthesis method. Background Technology

[0002] Ideal properties of high-energy-density materials (HEDMs) include high detonation velocity and pressure, high density, good thermal stability, good environmental compatibility, and low sensitivity to impact and friction. Nitrogen-rich heterocyclic compounds typically possess high density and high enthalpy of formation, making them an important class of novel high-energy-density materials. The structure of HEDMs consists of a heterocyclic backbone and explosive groups. Currently, azole and aziridine compounds are attracting significant attention in the development of novel energetic materials, such as tetrazolium, 1,2,4-triazole, 1,2,3-triazole, pyrazole, imidazole, triazine, and tetrazine compounds.

[0003] Energetic compounds derived from high-nitrogen energetic heterocycles and functional groups such as nitro (-NO2), oxynitro (-ONO2), nitramine (-NHNO2), and trinitromethyl have attracted attention due to their excellent detonation properties. Compared with mononitro compounds, trinitromethyl derivatives exhibit very high densities (Al, density: 1.87-1.96 g cm⁻¹). -3 Due to the high oxygen and nitrogen percentage content of high-energy molecules, this results in high detonation performance (AF, detonation velocity: 8511-8983 m / s). However, most high-energy trinitromethane derivatives have thermal decomposition temperatures below 150℃ (AF, thermal decomposition temperature: 73-175℃).

[0004]

[0005] Therefore, achieving low thermal decomposition temperature is a pressing problem that needs to be solved in the development and application of high-energy trinitromethyl derivatives. Summary of the Invention

[0006] The purpose of this invention is to provide a 3,8-dinitro-7-(trinitromethyl)pyrazole[5,1-c][1,2,4]triazine-4-amine and its synthesis method.

[0007] 3,8-Dinitro-7-(trinitromethyl)pyrazole[5,1-c][1,2,4]triazine-4-amine, with the following structural formula:

[0008]

[0009] The specific steps for synthesizing the above-mentioned 3,8-dinitro-7-(trinitromethyl)pyrazole[5,1-c][1,2,4]triazine-4-amine are as follows:

[0010] (1) Under the diazotization effect of hydrochloric acid and sodium nitrite, 2-(3-amino-1H-pyrazol-5-yl)acetic acid (I) reacts with sodium nitrite acetonitrile to prepare 2-(4-amino-3-nitropyrazolo[5,1-c][1,2,4]triazine-7-yl)acetic acid intermediate (II), as shown in the following reaction formula:

[0011]

[0012] (2) 2-(4-amino-3-nitropyrazolo[5,1-c][1,2,4]triazine-7-yl)acetic acid (II) was nitrated in a nitration system to generate 3,8-dinitro-7-(trinitromethyl)pyrazol[5,1-c][1,2,4]triazine-4-amine (TNFH), as shown in the following reaction formula:

[0013]

[0014] Further, in step (1), the molar ratio of 2-(3-amino-1H-pyrazole-5-yl)acetic acid to sodium nitrite is 1:1 to 10, preferably 1:1 to 1.2.

[0015] Furthermore, in step (1), the mass concentration of hydrochloric acid is 5-37%.

[0016] Further, in step (1), the molar ratio of 2-(3-amino-1H-pyrazol-5-yl)acetic acid to sodium nitrosonitrile is 1:1 to 10, preferably 1:1.2 to 1.5.

[0017] Furthermore, in step (1), the reaction temperature is 0–50°C and the reaction time is 1–24 h.

[0018] Furthermore, in step (1), the solvent is water, acetonitrile, methanol or ethanol.

[0019] Further, in step (1), after the reaction is completed, the reaction solution is filtered, the filter cake is washed with solvent and dried to obtain 2-(4-amino-3-nitropyrazolo[5,1-c][1,2,4]triazine-7-yl)acetic acid intermediate.

[0020] Further, in step (2), the nitration system is 68% nitric acid / 98% sulfuric acid, fuming nitric acid / 98% sulfuric acid, 100% nitric acid / 98% sulfuric acid, 68% nitric acid / 20% fuming sulfuric acid, fuming nitric acid / 20% fuming sulfuric acid or 100% nitric acid / 20% fuming sulfuric acid in a volume ratio of 1:0.5 to 1.

[0021] Furthermore, in step (2), the reaction temperature is -25 to 30°C, preferably 20 to 25°C, and the reaction time is 2 to 48 hours.

[0022] Further, in step (2), the molar ratio of 2-(4-amino-3-nitropyrazolo[5,1-c][1,2,4]triazine-7-yl)acetic acid (II) to nitric acid is 1:10 to 30.

[0023] Further, in step (2), after the reaction is complete, the mixture is poured into ice to quench it, stirred, filtered, and dried to obtain 3,8-dinitro-7-(trinitromethyl)pyrazole[5,1-c][1,2,4]triazine-4-amine.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] (1) The method of the present invention is simple, the experimental process is safe and efficient, and the maximum yield can reach 75%, which meets the conditions for scale-up production.

[0026] (2) As an energetic material, TNFH of the present invention exhibits a higher decomposition temperature than all existing high explosives based on trinitromethane, with an initial decomposition temperature of 205°C, while the decomposition temperature of existing high-energy trinitromethane derivatives does not exceed 200°C.

[0027] (3) The measured density of TNFH in this invention is 1.947 g / cm³. 3 The calculated detonation velocity is 9492 m / s, the calculated detonation pressure is 41.0 GPa, and the measured sensitivity is 192 J and 12 J, demonstrating excellent overall performance, superior to the currently used strongest military explosive, octogen (HMX, density 1.905 g / cm³). 3 It has a detonation velocity of 9144 m / s, a detonation pressure of 39.2 Gpa, and a sensitivity of 120 J and 7.4 J, and has the potential to replace the military explosive octogen. Attached Figure Description

[0028] Figure 1 This is the crystal structure diagram of TNFH;

[0029] Figure 2 A comparison of the thermal stability of typical trinitromethyl high-energy compounds and TNFH;

[0030] Figure 3 This is a DSC plot of TNFH;

[0031] Figure 4 The 1H NMR spectrum of (2-(4-amino-3-nitropyrazolo[5,1-c][1,2,4]triazine-7-yl)acetic acid);

[0032] Figure 5 The carbon spectrum of (2-(4-amino-3-nitropyrazolo[5,1-c][1,2,4]triazine-7-yl)acetic acid);

[0033] Figure 6 The hydrogen spectrum of TNFH;

[0034] Figure 7 This is the carbon spectrum of TNFH. Detailed Implementation

[0035] The present invention will be further described below with reference to specific embodiments and accompanying drawings.

[0036] Example 1

[0037] (1) Weigh 1.10 g (10.0 mmol) of 2-(3-amino-1H-pyrazol-5-yl)acetic acid into a 100 ml three-necked flask, add 10 ml of 37% hydrochloric acid and stir. After the solid is completely dissolved, add 0.90 g (12.0 mmol) of sodium nitrite dropwise and stir. Add 1.60 g (15.0 mmol) of sodium nitrite and stir the reaction at 0 °C for 12 h. After cooling, filter, wash with EtOH, and dry to obtain 1.99 g of brownish-yellow powder of intermediate (II) of 2-(4-amino-3-nitropyrazolo[5,1-c][1,2,4]triazine-7-yl)acetic acid, with a yield of 84.0%.

[0038] 1 H NMR (500MHz, DMSO-d6): δ = 3.92 (s), 7.13 (s), 9.36 (s), 9.88 (s) ppm. 13 C NMR (126MHz, DMSO-d6): δ = 100.61, 136.08, 139.01, 150.08, 155.62, 171.10ppm.

[0039] (2) Under stirring at 0°C, 1.38 g (10 mmol) of 2-(4-amino-3-nitropyrazolo[5,1-c][1,2,4]triazine-7-yl)acetic acid was slowly added to a 50 mL reaction flask containing 15 mL of fuming nitric acid and 10 mL of 98% sulfuric acid. After the addition was complete, the reaction mixture was placed at 25°C and stirred for 24 hours. After the reaction was completed, the system was quenched in ice water, stirred and filtered to obtain 2.70 g of 3,8-dinitro-7-(trinitromethyl)pyrazol[5,1-c][1,2,4]triazine-4-amine pale yellow powder, with a yield of 71.0%.

[0040] 1 H NMR (500MHz, DMSO-d6): δ = 9.69 (br) ppm. 13 C NMR (126MHz, DMSO-d6): δ = 120.87, 137.55, 138.72, 138.94, 141.09, 144.66ppm. IR (KBr): 1603.2,1544.2,1484.8,1411.5,1349.4,1343.4,1324.1,1311.7,1214.3,1144.1,1050.5,797.2,705.8,641.3,411.9,366.7,223.8cm -1 Elemental analysis for C6H2N 10 O 10 (374.14): calcd C, 19.26; H, 0.54; N, 37.44%. Found: C 19.26, H 0.59, N 37.39%.

[0041] Example 2

[0042] (1) Weigh 1.10 g (10.0 mmol) of 2-(3-amino-1H-pyrazol-5-yl)acetic acid into a 100 ml three-necked flask, add 12 ml of 37% hydrochloric acid and stir. After the solid is completely dissolved, add 0.75 g (10.0 mmol) of sodium nitrite dropwise and stir. Add 1.28 g (12.0 mmol) of sodium nitrite and stir the reaction at 0 °C for 24 h. After cooling, filter, wash with EtOH, and dry to obtain 2.08 g of brownish-yellow powder of intermediate (II) of 2-(4-amino-3-nitropyrazolo[5,1-c][1,2,4]triazine-7-yl)acetic acid, with a yield of 88.0%.

[0043] (2) 1.38 g (10 mmol) of 2-(4-amino-3-nitropyrazolo[5,1-c][1,2,4]triazine-7-yl)acetic acid was slowly added to a 100 mL reaction flask containing 18 mL of 100% nitric acid and 15 mL of 98% sulfuric acid under stirring at 0 °C. After the addition was complete, the reaction mixture was placed at 20 °C and stirred for 12 hours. After the reaction was completed, the system was quenched in ice water, stirred and filtered to obtain 3.23 g of 3,8-dinitro-7-(trinitromethyl)pyrazol[5,1-c][1,2,4]triazine-4-amine yellow powder, with a yield of 85.0%.

[0044] Figure 2 The graph shows a comparison of the thermal stability of typical high-energy trinitromethyl compounds and TNFH. It can be seen that the listed high-energy trinitromethane derivatives all have thermal decomposition temperatures below 180℃ (AF, thermal decomposition temperature is 73-175℃), while TNFH exhibits the highest decomposition temperature, with an initial decomposition temperature of 205℃.

Claims

1. 3,8-Dinitro-7-(trinitromethyl)pyrazole[5,1-c][1,2,4]triazine-4-amine, characterized in that, The structural formula is: 。 2. The method for synthesizing 3,8-dinitro-7-(trinitromethyl)pyrazole[5,1-c][1,2,4]triazine-4-amine according to claim 1, characterized in that, The specific steps are as follows: (1) Under the diazotization effect of hydrochloric acid and sodium nitrite, 2-(3-amino-1H-pyrazol-5-yl)acetic acid reacts with sodium nitrate acetonitrile to prepare 2-(4-amino-3-nitropyrazolo[5,1-c][1,2,4]triazine-7-yl)acetic acid intermediate, as shown in the following reaction formula: ； (2) 2-(4-amino-3-nitropyrazolo[5,1-c][1,2,4]triazine-7-yl)acetic acid was nitrated in a nitration system to generate 3,8-dinitro-7-(trinitromethyl)pyrazol[5,1-c][1,2,4]triazine-4-amine, as shown in the following reaction formula: 。 3. The synthesis method according to claim 2, characterized in that, In step (1), the molar ratio of 2-(3-amino-1H-pyrazol-5-yl)acetic acid to sodium nitrite is 1:1 to 1.2; the molar ratio of 2-(3-amino-1H-pyrazol-5-yl)acetic acid to sodium nitrate is 1:1.2 to 1.

5.

4. The synthesis method according to claim 3, characterized in that, In step (1), the mass concentration of hydrochloric acid is 5-37%; the reaction temperature is 0-50℃; and the reaction time is 1-24h.

5. The synthesis method according to claim 3, characterized in that, In step (1), the solvent is water, acetonitrile, methanol or ethanol.

6. The synthesis method according to claim 3, characterized in that, In step (1), after the reaction is complete, the reaction solution is filtered, the filter cake is washed with solvent and dried to obtain 2-(4-amino-3-nitropyrazolo[5,1-c][1,2,4]triazine-7-yl)acetic acid intermediate.

7. The synthesis method according to claim 3, characterized in that, In step (2), the nitration system is 68% nitric acid / 98% sulfuric acid, fuming nitric acid / 98% sulfuric acid, 100% nitric acid / 98% sulfuric acid, 68% nitric acid / 20% fuming sulfuric acid, fuming nitric acid / 20% fuming sulfuric acid or 100% nitric acid / 20% fuming sulfuric acid in a volume ratio of 1:0.5 to 1.

8. The synthesis method according to claim 3, characterized in that, In step (2), the reaction temperature is 20~25℃ and the reaction time is 2~48h.

9. The synthesis method according to claim 3, characterized in that, In step (2), the molar ratio of 2-(4-amino-3-nitropyrazolo[5,1-c][1,2,4]triazine-7-yl)acetic acid to nitric acid is 1:10 to 30.

10. The synthesis method according to claim 3, characterized in that, In step (2), after the reaction is complete, the mixture is poured into ice to quench it, stirred, filtered, and dried to obtain 3,8-dinitro-7-(trinitromethyl)pyrazole[5,1-c][1,2,4]triazine-4-amine.

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