Process for the preparation of 1,2,3-triazolyl high energy density oxidizers and applications thereof

Abstract

The application discloses a preparation method and application of 1,2,3-triazolyl high-energy-density oxidizer, and the 1,2,3-triazolyl oxidizer is composed of 2-gem-dinitromethyl-4,5-dinitro-1,2,3-triazole or / and 2-trinitromethyl-4,5-dinitro-1,2,3-triazole. The application aims at the problems of environmental pollution and insufficient energy level of the oxygen-rich component ammonium perchlorate used in the active propellant, and proposes a method of starting from 4-amino-5-nitro-1,2,3-triazole (ANTZ), controlling different nitration systems of mixed nitro-sulfur acid, and obtaining 2-gem-dinitromethyl-4,5-dinitro-1,2,3-triazole and 2-trinitromethyl-4,5-dinitro-1,2,3 triazole through three-step conversion respectively. The physical and chemical properties of the obtained 1,2,3-triazolyl high-energy-density oxidizer are fully calculated and tested, and the results show that the two novel solid oxidizers have excellent performance and have the potential to replace ammonium perchlorate and be applied in the field of solid propellants.

Description

Technical Field

[0001] This invention relates to the field of energetic materials technology, and in particular to a method for preparing 1,2,3-triazolyl high-energy-density oxidants and their applications. Background Technology

[0002] High-energy-density compounds are the main energy components of various energetic materials such as propellants, propellants, and mixed explosives. In propellant research, polynitro compounds, due to their high oxygen content, are considered as green solid oxidant components that can replace ammonium perchlorate. However, polynitro functional groups, such as trinitromethyl and dinitromethyl, have negative enthalpy of production, which reduces specific impulse to some extent, limiting the improvement of propellant performance. Nitrozole-rich frameworks have very high enthalpy of formation, and the planarity of monocyclic and fused-ring molecular frameworks facilitates efficient crystal stacking, thereby improving properties such as density and thermal stability. Therefore, introducing polynitro functional groups into nitrazole-rich frameworks can effectively construct high-energy oxidant molecules, thus simultaneously achieving both specific impulse and oxygen balance. These compounds exhibit high oxygen balance and energy density, perfectly meeting the design requirements of novel high-performance solid oxidants. Compared with the oxygen-rich component ammonium perchlorate currently used in propellants, these novel propellant components not only have a good positive oxygen balance but also excellent energy density and specific impulse levels. More importantly, this type of CHNO-type green high-energy oxidant does not contain chlorine, which can effectively avoid the environmental pollution problems caused by hydrogen chloride gas.

[0003] Among nitrogen-containing heterocyclic skeletons, 1,2,3-triazole exhibits a high positive enthalpy of formation (240 kJ / mol), higher than pyrazole (179 kJ / mol), imidazole (133 kJ / mol), and its isomer 1,2,4-triazole (182 kJ / mol). This aligns perfectly with the design requirements of high-density energetic materials, and its introduction into energetic compounds will undoubtedly enhance the overall performance of the compounds. However, due to the difficulty in its synthesis, research on such energetic compounds is limited, and their application in high-energy-density oxidants is even less reported. Therefore, the rational assembly of polynitro functional groups (trinitromethyl or dinitromethyl) with 1,2,3-triazole holds promise for obtaining a series of high-energy-density oxidants with superior performance, which is of significant research importance for the development of novel high-performance solid propellants. Summary of the Invention

[0004] The purpose of this invention is to address the aforementioned problems by providing a method for preparing a 1,2,3-triazolyl high-energy-density oxidant and its application. This invention utilizes a three-step reaction process through reasonable control of reaction conditions to efficiently synthesize a 1,2,3-triazolyl high-energy-density oxidant, thereby providing good technical support for the subsequent application of such compounds in the field of solid propellants.

[0005] The technical solution adopted in this invention is as follows: a 1,2,3-triazolyl high-energy-density oxidant, wherein the 1,2,3-triazolyl oxidant is composed of 2-gemindinitroxymethyl-4,5-dinitro-1,2,3-triazole or / and 2-trinitromethyl-4,5-dinitro-1,2,3-triazole.

[0006] Furthermore, the structural formula of the 2-genomicdinitromethyl-4,5-dinitro-1,2,3-triazole is as shown in Formula I, and the structural formula of the 2-trinitromethyl-4,5-dinitro-1,2,3-triazole is as shown in Formula II:

[0007]

[0008]

[0009] Furthermore, the 1,2,3-triazolyl oxidant is obtained by using 4-amino-5-nitro-1,2,3-triazole as a raw material, undergoing an oxidation reaction under sulfuric acid and hydrogen peroxide conditions, followed by reaction with bromoacetone under alkaline conditions, and finally obtaining the oxidant through a controlled nitration system of nitrate-sulfur mixed acid.

[0010] Furthermore, the present invention also includes a method for preparing a 1,2,3-triazolyl high-energy-density oxidant, comprising the following steps;

[0011] A. Using 4-amino-5-nitro-1,2,3-triazole as a raw material, an oxidation reaction was carried out under the conditions of sulfuric acid and hydrogen peroxide to obtain 4,5-dinitro-1,2,3-triazole;

[0012] B. Using 4,5-dinitro-1,2,3-triazole as a raw material, it is reacted with bromoacetone under alkaline conditions to obtain 2-acetonitrile-4,5-dinitro-1,2,3-triazole;

[0013] C. Using 2-propanone-4,5-dinitro-1,2,3-triazole as a raw material, the product is obtained by controlling the nitration system of nitrate-sulfur mixed acid.

[0014] Furthermore, the synthesis of the 4,5-dinitro-1,2,3-triazole specifically includes the following steps:

[0015] A1. Under ice bath conditions, hydrogen peroxide is added to concentrated sulfuric acid to obtain a mixed solution;

[0016] A2. Add 4-amino-5-nitro-1,2,3-triazole to the mixture in batches, then raise the temperature to room temperature and stir for a period of time;

[0017] A3. Pour the reaction solution into ice water, extract with ether, wash the organic phase with water, and then dry with anhydrous sodium sulfate to remove the solvent.

[0018] Furthermore, the synthesis of the 2-acetone-4,5-dinitro-1,2,3-triazole specifically includes the following steps:

[0019] B1. Add 4,5-dinitro-1,2,3-triazole to an aqueous solution of sodium hydroxide, then add an acetone solution of bromoacetone, and heat the reaction system to 80-100℃ (e.g., 80℃, 90℃, 95℃, 100℃, etc.) and react for a period of time.

[0020] B2. Cool to room temperature, remove acetone by vacuum rotary evaporation, then extract with ethyl acetate, dry the organic phase with anhydrous sodium sulfate, and separate by column chromatography to obtain the final product.

[0021] Furthermore, the specific operation of step C is as follows:

[0022] C1a. At 0-5℃ (e.g., 0℃, 1℃, 2℃, 3℃, 5℃, etc.), dissolve 2-acetone-4,5-dinitro-1,2,3-triazole in a mixed solution of sulfuric acid and nitric acid, with a volume ratio of sulfuric acid to nitric acid of 1:1. The concentration of the nitration system is 0.25-0.50M (e.g., 0.25M, 0.30M, 0.35M, 0.40M, 0.50M, etc.; the concentration of the nitration system must be within this range. When the system concentration is below 0.25M, it will cause over-reaction and the expected product will not be obtained; when the system concentration is above 0.5M, it will cause incomplete reaction of the raw materials and difficulty in separation), and the reaction time is 3-5 hours.

[0023] C2a, the reaction system is poured into ice water, the resulting solid is filtered, and washed with trifluoroacetic acid under nitrogen protection to give 2-ges-dinitromethyl-4,5-dinitro-1,2,3-triazole; or / and

[0024] C1b. At 0-5℃ (e.g., 0℃, 1℃, 2℃, 3℃, 5℃, etc.), dissolve 2-propanone-4,5-dinitro-1,2,3-triazole in sulfuric acid, add ammonium nitrate, and the molar ratio of 2-propanone-4,5-dinitro-1,2,3-triazole to ammonium nitrate is 1:8-12 (the molar ratio can be 1:8, 1:9, 1:10, 1:11, etc.; the molar ratio relationship must be within this range. When the molar ratio is lower than 1:8, the raw materials will react incompletely and separation will be difficult; when the molar ratio is greater than 1:12, the reaction will be over-reaction and the expected product will not be obtained), the reaction time is 3-5 days.

[0025] C2b. Extract the above reaction system with n-hexane, dry the organic phase with anhydrous sodium sulfate to remove the solvent, and obtain 2-trinitromethyl-4,5-dinitro-1,2,3-triazole.

[0026] Furthermore, the volume ratio of hydrogen peroxide to sulfuric acid is 1:1-2, the concentration of hydrogen peroxide is 30±10%, the concentration of sulfuric acid is 95±3%, the concentration of the oxidation system is 0.3-0.5M, and the oxidation reaction time is 24-36h.

[0027] Furthermore, the molar ratio of 4,5-dinitro-1,2,3-triazole, sodium hydroxide, and bromoacetone is 1:1-1.2:1.2-1.5 (the molar ratio can be 1:1:1.2, 1:1.1:1.3, 1:1.2:1.5, etc.), and the reaction time is 24-36 h.

[0028] In summary, due to the adoption of the above technical solutions, the beneficial effects of this invention are as follows: Addressing the environmental pollution and insufficient energy levels of ammonium perchlorate, the oxygen-rich component used in existing propellants, this invention proposes a method starting from 4-amino-5-nitro-1,2,3-triazole (ANTZ), and through controlling different nitration systems using mixed nitrate and sulfuric acid, to achieve a three-step conversion to obtain 2-gemethylene-4,5-dinitro-1,2,3-triazole (DNM-DNT) and 2-trinitromethyl-4,5-dinitro-1,2,3-triazole (TNM-DNT). The physicochemical properties of the resulting 1,2,3-triazole-based high-energy-density oxidants have been fully calculated and tested. The results show that the two novel solid oxidants have excellent performance and have the potential to replace ammonium perchlorate in the field of solid propellants. Attached Figure Description

[0029] Figure 1 It is compound 3 of Example 1 of this invention. 1 Hydrogen NMR spectrum;

[0030] Figure 2 It is the compound DNM-DNT of Example 1 of this invention. 1 Hydrogen NMR spectrum;

[0031] Figure 3 It is the compound DNM-DNT of Example 1 of this invention. 13 Carbon NMR spectrum;

[0032] Figure 4 It is compound TNM-DNT from Example 1 of this invention. 13 Carbon NMR spectrum;

[0033] Figure 5 This is a single-crystal structure diagram of the compound DNM-DNT of this invention;

[0034] Figure 6 This is a single-crystal structure diagram of the compound TNM-DNT of this invention. Detailed Implementation

[0035] The present invention will now be described in detail with reference to the accompanying drawings.

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0037] This invention provides a method for the efficient synthesis of 1,2,3-triazolyl high-energy-density oxidants. The method uses 4-amino-5-nitro-1,2,3-triazole (ANTZ), which is known from the literature, as the starting material. The oxidation reaction is carried out under sulfuric acid / hydrogen peroxide conditions. Then, acetone groups are introduced by reacting with bromoacetone under alkaline conditions. Finally, by controlling different nitration systems of nitrate and sulfuric acid, a total of three steps of transformation are performed to obtain 2-gem-dinitromethyl-4,5-dinitro-1,2,3-triazole (DNM-DNT) and 2-trinitromethyl-4,5-dinitro-1,2,3-triazole (TNM-DNT).

[0038] Example 1

[0039] The synthetic method of compound 4,5-dinitro-1,2,3-triazole 2, and the principle of its synthetic reaction are shown below:

[0040]

[0041] The specific steps are as follows:

[0042] S1. Under ice bath conditions, slowly add 1.0 mL of 30% hydrogen peroxide (concentration of 30%) to 2.0 mL of concentrated sulfuric acid (concentration of 98%) to obtain a mixture.

[0043] S2. Add 129.0 mg, 1.0 mmol of 4-amino-5-nitro-1,2,3-triazole in portions slowly to the mixture, then slowly raise the temperature to room temperature and continue stirring for 24 h.

[0044] S3. Pour the reaction solution into ice water, extract with ether (3 × 10.0 mL), wash the organic phase with water (3 × 5.0 mL), dry the organic phase with anhydrous sodium sulfate, and remove the solvent to obtain yellow oily product 2 (yield 71%).

[0045] Example 2

[0046] The synthetic method for compound 2-acetone-4,5-dinitro-1,2,3-triazole 3, and the principle of its synthetic reaction are as follows:

[0047]

[0048] The specific steps are as follows:

[0049] S1, 4,5-dinitro-1,2,3-triazole 2 (159.0 mg, 1.0 mmol) was added to an aqueous solution of sodium hydroxide (48.0 mg, 1.2 mmol) (1.0 mL);

[0050] S2. Add 5.0 mL of acetone solution containing bromoacetone (204.0 mg, 1.5 mmol) to the reaction system and heat the reaction system to 100 °C for 24 h.

[0051] S3. Cool to room temperature, remove acetone by vacuum rotary evaporation, then extract with ethyl acetate (3 × 10.0 mL), dry the organic phase with anhydrous sodium sulfate, evaporate to dryness and separate by column chromatography to give white compound 3 (yield 60%).

[0052] like Figure 1 As shown, 1 H NMR (400MHz, CD3CN) δ5.58 (s, 2H), 2.28 (s, 3H). 13 C NMR (101MHz, CD3CN) δ 198.6, 145.0 (t, J = 18.2Hz), 66.3, 27.1.

[0053] Example 3

[0054] The synthetic method for compound 2-gemindinitrmethyl-4,5-dinitro-1,2,3-triazole (DNM-DNT) is described below, and its single-crystal structure is shown in the figure. Figure 5 As shown:

[0055]

[0056] The specific steps are as follows:

[0057] S1. Compound 3 (215.0 mg, 1.0 mmol) was dissolved in a mixed solution of sulfuric acid (2.0 mL) and nitric acid (2.0 mL) at 0-5 °C, and stirred at this temperature for 4 h.

[0058] S2. Pour the reaction system into ice water, filter the obtained solid, and wash it with trifluoroacetic acid under nitrogen protection to obtain the white pure product DNM-DNT (36% yield).

[0059] like Figure 2 and Figure 3 As shown, 1 H NMR (400MHz, CD3CN) δ8.84 (s, 1H). 13C NMR (101MHz, CD3CN) δ147.5 (t, J = 21.2Hz), 107.6.IR (KBr pellet):υ3008, 2961, 1748, 1724, 1612, 1549, 1504, 1468, 1400, 1350, 1325, 1296, 1142, 1093, 1021, 994, 938, 893, 869, 810, 770, 748, 722, 654, 483, 421cm -1 ; elemental analysis (%) calcd for C3HN7O8 (263.08): C, 13.70; H, 0.38; N, 37.27; found: C, 13.34; H, 0.51, N, 36.88.

[0060] Example 4

[0061] The synthetic method for compound 2-trinitromethyl-4,5-dinitro-1,2,3-triazole (TNM-DNT) is as follows, and its single-crystal structure is shown in the figure. Figure 6 As shown:

[0062]

[0063] The specific steps are as follows:

[0064] S1. At 0-5℃, compound 3 (215.0 mg, 1.0 mmol) was dissolved in sulfuric acid (2.0 mL), and ammonium nitrate (800.0 mg, 10.0 mmol) was added. The mixture was reacted at room temperature for 3 days.

[0065] S2. Extract the reaction system with n-hexane, dry the organic phase with anhydrous sodium sulfate to remove the solvent, and give a white pure product 4 (54% yield).

[0066] like Figure 4 As shown, 13 C NMR (CDCl3): δ147.15 (t, J=16Hz), 116.66; IR (KBr pellet): υ3459, 2892, 1635, 1316, 1589, 1571, 1514, 1411, 1359, 1327, 1270, 1145, 931, 858, 837, 813, 793, 747cm -1 ;elemental analysis(%)calcd for C3N8O 10 (308.08):C,11.70;H,0.00,N,36.37;found:C,11.73;H,0.18,N,33.77.

[0067] The physicochemical properties of the two products (DNM-DNT and TNM-DNT) were fully calculated and tested, and the experimental results are shown in Table 1.

[0068] Table 1 Physicochemical properties of DNM-DNT and TNM-DNT

[0069]

[0070] As shown in Table 1, the detonation performance of the obtained 1,2,3-triazolyl high-energy-density oxidant is comparable to that of RDX (RDX, chemical name cyclotrimethylenetrinitramine), and it has excellent oxygen balance, making it a potential replacement for ammonium perchlorate in the field of solid propellants.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a 1,2,3-triazolyl high-energy-density oxidant, characterized in that, Includes the following steps: A. Using 4-amino-5-nitro-1,2,3-triazole as a raw material, an oxidation reaction was carried out under the conditions of sulfuric acid and hydrogen peroxide to obtain 4,5-dinitro-1,2,3-triazole; B. Using 4,5-dinitro-1,2,3-triazole as a raw material, it is reacted with bromoacetone under alkaline conditions to obtain 2-acetonitrile-4,5-dinitro-1,2,3-triazole; C. Using 2-propanone-4,5-dinitro-1,2,3-triazole as a raw material, the reaction is carried out by controlling the nitration system of nitrate-sulfur mixed acid; The specific operation of step C is as follows: C1b. At 0-5℃, 2-propanone-4,5-dinitro-1,2,3-triazole is dissolved in sulfuric acid, and ammonium nitrate is added. The molar ratio of 2-propanone-4,5-dinitro-1,2,3-triazole to ammonium nitrate is 1:8-12, and the reaction time is 3-5 days. C2b. Extract the above reaction system with n-hexane, dry the organic phase with anhydrous sodium sulfate to remove the solvent, and obtain 2-trinitromethyl-4,5-dinitro-1,2,3-triazole.

2. The preparation method according to claim 1, characterized in that, The synthesis of the 4,5-dinitro-1,2,3-triazole specifically includes the following steps: A1. Under ice bath conditions, hydrogen peroxide is added to concentrated sulfuric acid to obtain a mixed solution; A2. Add 4-amino-5-nitro-1,2,3-triazole to the mixture in batches, then raise the temperature to room temperature and stir for a period of time; A3. Pour the reaction solution into ice water, extract with ether, wash the organic phase with water, and then dry with anhydrous sodium sulfate to remove the solvent.

3. The preparation method according to claim 1, characterized in that, The synthesis of the 2-acetone-4,5-dinitro-1,2,3-triazole specifically includes the following steps: B1. Add 4,5-dinitro-1,2,3-triazole to an aqueous solution of sodium hydroxide, then add an acetone solution of bromoacetone, and heat the reaction system to 80-100℃ for a period of time. B2. Cool to room temperature, remove acetone by vacuum rotary evaporation, then extract with ethyl acetate, dry the organic phase with anhydrous sodium sulfate, and separate by column chromatography to obtain the final product.

4. The preparation method according to claim 2, characterized in that, The volume ratio of hydrogen peroxide to sulfuric acid is 1:1-2, the concentration of hydrogen peroxide is 30±10%, the concentration of sulfuric acid is 95±3%, the concentration of the oxidation system is 0.3-0.5M, and the oxidation reaction time is 24-36h.

5. The method for preparing the 1,2,3-triazolyl high-energy-density oxidant as described in claim 3, characterized in that, The molar ratio of 4,5-dinitro-1,2,3-triazole, sodium hydroxide, and bromoacetone is 1:1-1.2:1.2-1.5, and the reaction time is 24-36 h.

6. The application of a 1,2,3-triazolyl high-energy-density oxidizer in solid propellants, characterized in that, The 1,2,3-triazolyl high-energy-density oxidant is 2-gesodenitroxymethyl-4,5-dinitro-1,2,3-triazole, or 2-trinitromethyl-4,5-dinitro-1,2,3-triazole.

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