3, 8-dinitro-7-(trinitromethyl) pyrazole [5, 1-c] [1, 2, 4] triazine-4-amine and synthetic method thereof

Abstract

The invention discloses 3, 8-dinitro-7-(trinitromethyl) pyrazole [5, 1-c] [1, 2, 4] triazine-4-amine and a synthesis method thereof. According to the method, 2-(3-amino-1H-pyrazol-5-yl) acetic acid is taken as a raw material, water is taken as a solvent, the 2-(3-amino-1H-pyrazol-5-yl) acetic acid and sodium nitroacetonitrile are subjected to ring closing to obtain an intermediate containing 5-6 condensed rings, then nitric acid / sulfuric acid is used for nitration of the condensed ring intermediate, and the 3, 8-dinitro-7-(trinitromethyl) pyrazol [5, 1-c] [1, 2, 4] triazine-4-amine is obtained. The synthesis method is simple and high in yield, the 3, 8-dinitro-7-(trinitromethyl) pyrazol [5, 1-c] [1, 2, 4] triazine-4-amine has high decomposition temperature, the initial decomposition temperature is 205 DEG C, the actual 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 measurement sensitivity is 192 J and 12 J, and the 3, 8-dinitro-7-(trinitromethyl) pyrazol [5, 1-c] [1, 2, 4] triazine-4-amine has excellent comprehensive performance.

Description

Technical Field

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

[0002] The ideal properties of high energy density materials (HEDM) 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 are usually characterized by high density and high formation enthalpy and are an important new class of high energy density materials. The structure of HEDM consists of a heterocyclic backbone and an explosive group. At present, azole and azine compounds have attracted much attention in the development of new energetic materials, such as tetrazoles, 1,2,4-triazoles, 1,2,3-triazoles, pyrazoles, imidazoles, triazines, and tetrazines.

[0003] Energetic compounds obtained by combining high nitrogen energetic heterocycles with functional groups such as nitro (-NO2), oxynitro (-ONO2), nitramine (-NHNO2), and trinitromethyl have attracted attention due to their excellent detonation performance. Compared with mononitro compounds, trinitromethyl derivatives show a very high density (AI, density: 1.87-1.96 g cm -3 ), due to the high oxygen and nitrogen percentage content of high-energy molecules, this leads to higher detonation performance (AF, detonation velocity: 8511-8983m / s). However, the thermal decomposition temperature of most high-energy trinitromethane derivatives is lower than 150°C (AF, thermal decomposition temperature: 73-175°C).

[0004]

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

[0006] The present invention aims to provide 3,8-dinitro-7-(trinitromethyl)pyrazolo[5,1-c][1,2,4]triazine-4-amine and a synthesis method thereof.

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

[0008]

[0009] The synthetic method of the above 3,8-dinitro-7-(trinitromethyl)pyrazolo[5,1-c][1,2,4]triazine-4-amine comprises the following specific steps:

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

[0011]

[0012] (2) 2-(4-amino-3-nitropyrazolo[5,1-c][1,2,4]triazine-7-yl)acetic acid (II) is subjected to a nitration reaction in a nitration system to generate 3,8-dinitro-7-(trinitromethyl)pyrazolo[5,1-c][1,2,4]triazine-4-amine (TNFH), and the reaction formula is as follows:

[0013]

[0014] Furthermore, in step (1), the molar ratio of 2-(3-amino-1H-pyrazol-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 to 37%.

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

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

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

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

[0020] Furthermore, 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 1:0.5-1.

[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] Furthermore, 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] Furthermore, in step (2), after the reaction is completed, the mixture is poured into ice to quench, stirred, filtered, and dried to obtain 3,8-dinitro-7-(trinitromethyl)pyrazolo[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) The TNFH of the present invention, as an energetic material, 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 of the present invention is 1.947 g / cm 3 The calculated detonation velocity is 9492m / s, the calculated detonation pressure is 41.0Gpa, and the measured sensitivity is 192J and 12J, which has excellent comprehensive performance and is better than the strongest military explosive currently used, octochrome (HMX, density 1.905g / cm 3 , detonation velocity is 9144m / s, detonation pressure is 39.2Gpa, sensitivity is 120J, 7.4J), and it has the potential to replace the military explosive octogen. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0029] Figure 2 This is a comparison chart of the thermal stability of typical trinitromethyl high-energy compounds and TNFH;

[0030] Figure 3 is the DSC graph of TNFH;

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

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

[0033] Figure 6 is the hydrogen spectrum of TNFH;

[0034] Figure 7 This is the carbon spectrum of TNFH. DETAILED DESCRIPTION

[0035] The present invention will be further described below in conjunction with 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 nitroacetonitrile and stir at 0°C to react for 12 h. After cooling, filter, wash with EtOH, and dry to obtain 1.99 g of brown-yellow powder of 2-(4-amino-3-nitropyrazolo[5,1-c][1,2,4]triazine-7-yl)acetic acid intermediate (II) 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 bottle containing 15 ml of fuming nitric acid and 10 ml of 98% sulfuric acid. After the addition was completed, the reaction mixture was stirred at 25°C for 24 hours. After the reaction was completed, the system was poured into ice water for quenching, stirred and filtered to obtain 2.70 g of light yellow powder of 3,8-dinitro-7-(trinitromethyl)pyrazolo[5,1-c][1,2,4]triazine-4-amine 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 nitroacetonitrile and stir at 0°C to react. Fully react for 24 h, cool and filter, wash with EtOH, and dry to obtain 2.08 g of brown-yellow powder of 2-(4-amino-3-nitropyrazolo[5,1-c][1,2,4]triazine-7-yl)acetic acid intermediate (II) 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 bottle containing 18 ml of 100% nitric acid and 15 ml of 98% sulfuric acid at 0°C with stirring. After the addition was completed, the reaction mixture was stirred at 20°C for 12 hours. After the reaction was completed, the system was poured into ice water for quenching, stirred and filtered to obtain 3.23 g of yellow powder of 3,8-dinitro-7-(trinitromethyl)pyrazolo[5,1-c][1,2,4]triazine-4-amine with a yield of 85.0%.

[0044] Figure 2 This is a comparison chart of the thermal stability of typical trinitromethyl high-energy compounds and TNFH. It can be seen that the thermal decomposition temperatures of the listed high-energy trinitromethane derivatives are all lower than 180°C (AF, thermal decomposition temperature is 73-175°C), while TNFH shows the highest decomposition temperature, and its initial decomposition temperature is 205°C.

Claims

1. 3,8-Dinitro-7-(trinitromethyl)pyrazolo[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)pyrazolo[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 action of hydrochloric acid and sodium nitrite, 2-(3-amino-1H-pyrazol-5-yl)acetic acid reacts with sodium nitroacetonitrile to prepare 2-(4-amino-3-nitropyrazolo[5,1-c][1,2,4]triazine-7-yl)acetic acid intermediate, the reaction formula is as follows: ； (2) 2-(4-amino-3-nitropyrazolo[5,1-c][1,2,4]triazine-7-yl)acetic acid is subjected to a nitration reaction in a nitration system to generate 3,8-dinitro-7-(trinitromethyl)pyrazolo[5,1-c][1,2,4]triazine-4-amine, and the reaction formula is as follows: 。 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 10, preferably 1:1 to 1.2; the molar ratio of 2-(3-amino-1H-pyrazol-5-yl)acetic acid to sodium nitroacetonitrile is 1:1 to 10, preferably 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° C., and the reaction time is 1-24 h.

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 completed, the reaction solution is filtered, the filter cake is washed with a solvent, and dried to obtain a 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 nitrating 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 1:0.5-1.

8. The synthesis method according to claim 3, characterized in that 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.

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 completed, the mixture is poured into ice to quench, stirred, filtered, and dried to obtain 3,8-dinitro-7-(trinitromethyl)pyrazolo[5,1-c][1,2,4]triazine-4-amine.

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