High-nitrogen compound DTTZ, ionic salt thereof and preparation method of ionic salt

Abstract

The invention provides a high-nitrogen compound DTTZ, and an ionic salt and a preparation method thereof. The structure of the DTTZ is shown as a formula I. The invention further provides a preparation method of the high-nitrogen compound DTTZ. The high nitrogen compound provided by the invention has the characteristics of high enthalpy of formation, good stability, low sensitivity and the like, can be used as a fuel component of a solid propellant, and has application potential in the aspect of high-safety and high-energy-density materials.

Description

Technical Field

[0001] The present invention belongs to the technical field of energetic materials, and in particular relates to a high-nitrogen compound DTTZ, an ionic salt thereof and a preparation method thereof. Background Art

[0002] High-nitrogen compounds offer unique advantages for constructing novel energetic materials with low mechanical sensitivity, excellent thermal stability, and high density, attracting widespread attention from researchers both domestically and internationally. The density of high-nitrogen compounds increases as they evolve from acyclic to monocyclic, polycyclic, and cage-type rings. High-nitrogen fused-ring compounds, in particular, possess greater ring tension within their backbones, resulting in higher energy release upon ring opening. Furthermore, fused-ring structures exhibit greater conjugation than monocyclic structures, facilitating the delocalized resonance of π electrons over a wider range. This results in a more uniform charge distribution within these high-nitrogen compounds, enhancing their stability. This greater conjugation contributes to the excellent planar properties of high-nitrogen fused-ring backbones, often forming π-π stacking between their faces, ultimately resulting in a layered structure. This layered structure reduces the sensitivity of high-nitrogen compounds to external mechanical stimuli. High-nitrogen fused-ring backbones also possess more C=N, N=N, and N-N bonds than monocyclic and linked rings, resulting in higher enthalpies of formation. These advantages allow compounds with high-nitrogen fused-ring backbones to balance energy and stability, achieving a favorable balance between detonation performance and stability, thus becoming an emerging class of fused-ring, high-nitrogen materials. Theoretical and practical evidence has demonstrated that high-nitrogen fused-ring structures possess excellent detonation performance and safety, making them recognized as energetic backbones with significant research potential.

[0003] At present, the fused ring skeleton precursors used in the synthesis of most fused ring tetrazine high nitrogen compounds were synthesized by Chavez (Chavez DE, Hiskey M A. Synthesis of the bi-heterocyclic parent ring system 1,2,4-triazolo[4,3-b][1,2,4,5]tetrazine and some 3,6-disubstituted derivatives. Journal of Heterocyclic Chemistry, 1998, 35(6): 1329-1332.) in 1998 to synthesize 6-(3,5-dimethyl-pyrazol-1-yl)-[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine and 3-(3,5-dimethyl-pyrazol-1-yl)-6-hydrazino-1,2,4,5-tetrazine. Based on the work of Chavez et al., Palysaeva (Palysaeva NV, Kumpan KP, Struchkova M IA direct approach to a6-hetarylamino[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine library. Organic Letters, 2014, 16(2):406-409.) proposed a nucleophilic substitution reaction using 6-(3,5-dimethyl-pyrazol-1-yl)-[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine as a substrate in 2014. However, conventional high-nitrogen compounds still have shortcomings in terms of stability, sensitivity, and other effects.

[0004] Therefore, how to provide a high-nitrogen compound with excellent performance has become an urgent problem to be solved. Summary of the Invention

[0005] To address the shortcomings of the existing technology, the present invention provides a high-nitrogen compound, DTTZ, an ionic salt thereof, and a method for preparing the same. The high-nitrogen compound provided by the present invention has high formation enthalpy, good stability, and low sensitivity. It can be used as a fuel component in solid propellants and has potential application in high-safety, high-energy-density materials.

[0006] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0007] In the first aspect, the present invention provides a high nitrogen compound N 6 -(1,2,4-triazol-3-yl)-[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine (DTTZ), the structure of which is shown in Formula I:

[0008]

[0009] The high-nitrogen compounds with the above-mentioned specific structures have the characteristics of high formation enthalpy, good stability and low sensitivity. They can be used as fuel components of solid propellants and have application potential in high-safety and high-energy density materials.

[0010] In a second aspect, the present invention provides an ionic salt of the high nitrogen compound DTTZ as described above, wherein the structure of the ionic salt of DTTZ is shown in Formula II:

[0011]

[0012] in Selected from guanidino, amino, hydrazine, hydroxylamino, triaminotriazolotriazole or triaminotriazole.

[0013] In a third aspect, the present invention provides a method for preparing the high-nitrogen compound DTTZ as described above, wherein the method for preparing DTTZ comprises the following steps:

[0014] The compound 6-(3,5-dimethyl-pyrazol-1-yl)-[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine (BTT), 3-amino-1,2,4-triazole and a base are mixed and reacted to obtain the DTTZ.

[0015] Preferably, the molar ratio of the 6-(3,5-dimethyl-pyrazol-1-yl)-[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine to 3-amino-1,2,4-triazole is 1:(0.4-2), for example, 1:0.4, 1:1, 1:1.5 or 1:2, etc., but is not limited to the values listed above, and other values not listed within the above numerical range are also applicable.

[0016] Preferably, the base comprises any one of cesium carbonate, potassium carbonate, sodium carbonate or triethylamine, or a combination of at least two thereof.

[0017] Preferably, the molar ratio of the 6-(3,5-dimethyl-pyrazol-1-yl)-[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine to the base is 1:(0.5-2), for example, 1:0.5, 1:1, 1:1.5 or 1:2, etc., but is not limited to the values listed above, and other values not listed within the above numerical range are also applicable.

[0018] Preferably, the mixed reaction temperature is 50-120°C, and the time is 0.1-12h, wherein the temperature can be 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C or 120°C, etc., and the time can be 0.1h, 0.5h, 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h or 12h, etc., but are not limited to the values listed above. Other values not listed within the above numerical range are also applicable.

[0019] Preferably, after the mixing reaction, the pH is adjusted to acidic with acid, and then a base and an acid are added in sequence.

[0020] Preferably, the acid comprises any one of hydrochloric acid, nitric acid or sulfuric acid, or a combination of at least two thereof.

[0021] In a fourth aspect, the present invention further provides a method for preparing the ionic salt of the high nitrogen compound DTTZ as described above, the preparation method comprising the following steps:

[0022] The DTTZ is reacted with a cationic precursor to obtain an ionic salt of the DTTZ.

[0023] Preferably, the cationic precursor includes monoaminoguanidine carbonate, guanidine carbonate, ammonia water, hydrazine hydrate, hydroxylamine hydrochloride, triamino-1,2,4-triazole nitrate or triamino-1,2,4-triazole hydrochloride.

[0024] Preferably, the molar ratio of DTTZ to cationic precursor is 1:(0.5-1.3), for example, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2 or 1:1.3, etc., but is not limited to the values listed above. Other values not listed within the above numerical range are also applicable.

[0025] Preferably, the temperature for the reaction of DTTZ with the cationic precursor is 20-80°C, for example, 20°C, 30°C, 40°C, 50°C, 60°C, 70°C or 80°C, but is not limited to the above values. Other values not listed within the above range are also applicable.

[0026] Preferably, the reaction time of DTTZ and the cationic precursor is 0.5-8 h, for example, 0.5 h, 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h or 8 h, but is not limited to the above values. Other values not listed in the above range are also applicable.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The present invention provides a high nitrogen compound N with a specific structure. 6-(1,2,4-Triazol-3-yl)-[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine (DTTZ) and its ionic salts have the characteristics of high formation enthalpy, good stability and low sensitivity. They can be used as fuel components of solid propellants and have application potential in high-safety and high-energy density materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is N provided in Example 1 6 H NMR spectrum of -(1,2,4-triazol-3-yl)-[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine;

[0030] Figure 2 is the H NMR spectrum of the monoaminoguanidine salt of DTTZ provided in Example 3;

[0031] Figure 3 This is the hydrogen nuclear magnetic resonance spectrum of the guanidine salt of DTTZ provided in Example 4. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0033] Example 1

[0034] This example provides a method for synthesizing N under high pressure conditions. 6 -(1,2,4-triazol-3-yl)-[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine, the method is carried out according to the following steps:

[0035] Step 1: Place 6-(3,5-dimethyl-pyrazol-1-yl)-[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine (BTT) (500 mg, 1.0 eq, 2.31 mmol), 3-amino-1,2,4-triazole (233 mg, 1.2 eq, 2.77 mmol), cesium carbonate (750 mg, 1.0 eq, 2.31 mmol) and acetonitrile (10 mL) in a high-pressure reactor, react at 100 ° C for 4 h, and cool to room temperature.

[0036] Step 2: After the reaction is completed, 7 mL of 2 mol / L hydrochloric acid is added dropwise to the reaction solution to adjust the pH to acidic, then 7 mL of 2 mol / L sodium hydroxide is added, and finally 7 mL of 2 mol / L hydrochloric acid is added, filtered, and dried naturally to obtain a brown solid N 6-(1,2,4-triazol-3-yl)-[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine 335 mg, yield 71.3%.

[0037] The product obtained in Example 1 was subjected to nuclear magnetic resonance hydrogen spectrum (1H NMR) analysis, and the results were as follows: 1H NMR (700 MHz, DMSO-d6) δ 13.86 (s, 1H), 11.71 (s, 1H), 9.50 (s, 1H), 8.49 (s, 1H) (as Figure 1 shown).

[0038] Example 2

[0039] This example provides a method for synthesizing N 6 -(1,2,4-triazol-3-yl)-[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine, the method is carried out according to the following steps:

[0040] Step 1: Place 6-(3,5-dimethyl-pyrazol-1-yl)-[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine (BTT) (500 mg, 1.0 eq, 2.31 mmol), 3-amino-1,2,4-triazole (233 mg, 1.2 eq, 2.77 mmol), cesium carbonate (750 mg, 1.0 eq, 2.31 mmol) and acetonitrile (10 mL) in a three-necked flask, reflux at 80 ° C for 0.1 h, and cool to room temperature.

[0041] Step 2: After the reaction is completed, 7 mL of 2 mol / L hydrochloric acid is added dropwise to the reaction solution to adjust the pH to acidic, then 7 mL of 2 mol / L sodium hydroxide is added, and finally 7 mL of 2 mol / L hydrochloric acid is added, filtered, and dried naturally to obtain a brown solid N 6 -(1,2,4-triazol-3-yl)-[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine 375 mg, yield 79.8%.

[0042] The results of hydrogen nuclear magnetic resonance (HNMR) spectrum of the product obtained in this example were the same as those in Example 1.

[0043] Example 3

[0044] This example provides a method for synthesizing an aminoguanidine salt of DTTZ, which is carried out according to the following steps:

[0045] DTTZ (200 mg, 1.0 eq, 1.00 mmol), monoaminoguanidine carbonate (140 mg, 1.0 eq, 1.00 mmol), and methanol (8 mL) were placed in a three-necked flask. The reaction mixture was stirred at 60°C for 4 h. After the reaction was completed, the mixture was cooled to room temperature and filtered. The filter cake was slurried with methanol and air-dried to obtain 237 mg of DTTZ monoaminoguanidine salt as a black solid with a yield of 85.2%.

[0046] The product obtained in Example 3 was subjected to nuclear magnetic resonance hydrogen spectrum (1H NMR) analysis, and the results were as follows: 1H NMR (700 MHz, DMSO-d6) δ 12.42 (s, 1H), 9.29 (s, 1H), 8.91 (s, 1H), 7.67 (s, 1H), 7.38 (s, 4H), 4.70 (s, 2H) (as Figure 2 shown).

[0047] Example 4

[0048] This example provides a method for synthesizing a guanidine salt of DTTZ, which is carried out according to the following steps:

[0049] DTTZ (400 mg, 2.0 eq, 2.00 mmol), guanidine carbonate (180 mg, 1.0 eq, 1.00 mmol), and methanol (8 mL) were placed in a three-necked flask. The reaction mixture was stirred at 60°C for 4 h. After the reaction was completed, the mixture was cooled to room temperature and filtered. The filter cake was slurried with methanol and air-dried to obtain 469 mg of the guanidine salt of DTTZ as a black solid with a yield of 89.1%.

[0050] The product obtained in Example 4 was subjected to nuclear magnetic resonance hydrogen spectrum (1H NMR) analysis, and the results were as follows: 1H NMR (700 MHz, DMSO-d6) δ 12.41 (s, 1H), 8.89 (s, 1H), 7.66 (s, 1H), 7.46 (s, 6H) (as Figure 3 shown).

[0051] Effect test:

[0052] The DTTZ and its ionic salt provided in the above examples were tested and compared with the existing compound CL-20 (hexanitrohexaazaisowurtzitane). The results are as follows:

[0053]

[0054] [a] Density was measured by gas pycnometer (25°C); [b] Decomposition temperature (onset, DSC, 5°C·min -1); [c] Formation enthalpy, based on the calculation results of Gaussian 09 (vB.01); [d] Detonation velocity, based on the calculation results of Explo5 (v6.01); [e] Detonation pressure, based on the calculation results of Explo5 (v6.01); [f] Impact sensitivity, tested with reference to GB / T 21567-2008; [g] Friction sensitivity, tested with reference to GB / T 21566-2008.

[0055] From the above results, it can be found that the high-nitrogen compounds and ionic salts thereof provided by the present invention have higher formation enthalpy, higher sensitivity and better reliability than existing compounds.

[0056] The applicant states that while the above-described embodiments illustrate the high-nitrogen compound DTTZ, its ionic salt, and its preparation method, the present invention is not limited to these embodiments. This does not necessarily mean that the present invention must rely on these embodiments for implementation. Those skilled in the art will appreciate that any improvements to the present invention, equivalent substitutions for raw materials in the products of the present invention, addition of auxiliary ingredients, and selection of specific methods, etc., fall within the scope of protection and disclosure of the present invention.

[0057] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

[0058] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A high nitrogen compound DTTZ, characterized in that The structure of DTTZ is shown in Formula I:

2. An ionic salt of the high nitrogen compound DTTZ according to claim 1, characterized in that: The ionic salt structure of DTTZ is shown in Formula II: in Selected from guanidino, amino, hydrazine, hydroxylamino, triaminotriazolotriazole or triaminotriazole.

3. A method for preparing the high nitrogen compound DTTZ according to claim 1, characterized in that: The preparation method of DTTZ comprises the following steps: The compound 6-(3,5-dimethyl-pyrazol-1-yl)-[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine, 3-amino-1,2,4-triazole and a base are mixed for reaction to obtain the DTTZ.

4. The preparation method according to claim 3, characterized in that The molar ratio of the 6-(3,5-dimethyl-pyrazol-1-yl)-[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine to 3-amino-1,2,4-triazole is 1:(0.4-2).

5. The preparation method according to claim 3 or 4, characterized in that The base includes any one or a combination of at least two of cesium carbonate, potassium carbonate, sodium carbonate or triethylamine; Preferably, the molar ratio of the 6-(3,5-dimethyl-pyrazol-1-yl)-[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine to the base is 1:(0.5-2); Preferably, the mixed reaction temperature is 50-120° C., and the time is 0.1-12 h.

6. The preparation method according to any one of claims 3 to 5, characterized in that After the mixing reaction, the pH is adjusted to acidic with acid, and then a base and an acid are added in sequence; Preferably, the acid comprises any one of hydrochloric acid, nitric acid or sulfuric acid, or a combination of at least two thereof.

7. A method for preparing the ionic salt of the high nitrogen compound DTTZ according to claim 2, characterized in that: The preparation method comprises the following steps: The DTTZ is reacted with a cationic precursor to obtain an ionic salt of the DTTZ.

8. The preparation method according to claim 7, characterized in that The molar ratio of DTTZ to cationic precursor is 1:(0.5-1.3); Preferably, the cationic precursor includes monoaminoguanidine carbonate, guanidine carbonate, ammonia water, hydrazine hydrate, hydroxylamine hydrochloride, triamino-1,2,4-triazole nitrate or triamino-1,2,4-triazole hydrochloride.

9. The preparation method according to claim 7 or 8, characterized in that The temperature for the reaction of DTTZ with the cationic precursor is 20-80°C.

10. The preparation method according to any one of claims 7 to 9, characterized in that: The reaction time of DTTZ and cationic precursor is 0.5-8h.

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