Oxidized furazan hydrazone-based energetic compounds and methods of synthesis thereof

Abstract

The application discloses an oxidized furazan hydrazone energetic compound and a synthesis method thereof. The steps are as follows: 3-methyl-4-formyl-2-oxofurazan is obtained by reacting trans-butene aldehyde with sodium nitrite; 3-hydrazyl-4-amino-1,2,4-triazole hydrochloride is obtained by reacting 3-methyl-4-formyl-2-oxofurazan with sodium nitrite solution and stannous chloride dihydrate under hydrogen chloride gas; and then, the target product is obtained by condensation reaction of 3-methyl-4-formyl-2-oxofurazan. The density of the target product is 1.610 g / cm 3 , the theoretical detonation velocity is 7677 m / s, the detonation pressure is 21.0 GPa, is close to 2,4,6-trinitrotoluene (TNT, detonation velocity: 6881 m / s, detonation pressure: 19.5 GPa), the test friction sensitivity is about 360 N, the impact sensitivity is greater than 40 J, lower than TNT (352 N, 15 J), and the method for synthesizing the oxidized furazan hydrazone energetic compound is simple in operation, high in yield and high in safety.

Description

Technical Field

[0001] The invention belongs to the field of energetic materials and relates to an oxidized furazanhydrazone energetic compound and a synthesis method thereof. Background Art

[0002] Nitrogen-rich heterocyclic compounds are an important new class of high energy density materials (HEDMs) because they generally have the characteristics of high density and high formation enthalpy. Among all five-membered heterocyclic rings, oxadiazole has attracted widespread attention due to its inherent oxygen atom, which can increase the oxygen content and improve the oxygen balance, thereby improving the performance of the compound. Oxadiazole has five forms: 1,2,4-oxadiazole, 1,2,5-oxadiazole (furazan), 1,3,4-oxadiazole, 1,2,3-oxadiazole and 1,2,5-oxadiazole-2-oxy (furazan oxide). The furazan ring has a high positive formation enthalpy (219 kJ mol -1 ) has application potential in the fields of propellants and explosives. In addition, furazan oxide is an N-oxidized derivative of furazan, which further improves the oxygen balance and formation enthalpy of the furazan ring skeleton (226kJ mol -1 Studies have shown that by introducing an oxidized furazan ring into the molecular skeleton, the molecular density can be increased by approximately 0.06-0.08 g cm -3 , the detonation velocity increases by about 300 m s -1 Therefore, a large number of energetic compounds containing furazan oxide have been studied, and the modification strategy of combining furazan oxide with other nitrogen-rich heterocyclic skeletons is one of the more active research directions in the synthesis of energetic materials.

[0003] In recent years, two energetic materials based on furazan oxide skeletons have been synthesized. For example, the tricyclic compound bis(nitrofurazan) (A) furazan oxide has excellent detonation performance (D = 8930 m s -1 Another example, 3,3'-dinitro-4,4'-azofurazan (B), showed a high density (2.0 g cm -3 ) and excellent detonation performance (D = 10000ms -1 ), both significantly outperform RDX. Unfortunately, both compounds have high shock sensitivity (A: 3J; B: <1J). Summary of the Invention

[0004] The present invention aims to provide an oxidized furazanhydrazone energetic compound and a synthesis method thereof.

[0005] The technical solution to achieve the purpose of the present invention is: an oxidized furazanhydrazone energetic compound having the following structure:

[0006]

[0007] The method for synthesizing the above compound comprises:

[0008] (1) a step of preparing 3-methyl-4-formyl-2-furoxan (2) by reacting trans-crotonaldehyde with sodium nitrite,

[0009]

[0010] (2) a step of reacting 3,5-diaminotriazole with a sodium nitrite solution and stannous chloride dihydrate under hydrogen chloride gas conditions to obtain 3-hydrazino-4-amino-1,2,4-triazole hydrochloride (4),

[0011]

[0012] (3) a step of reacting 3-hydrazino-4-amino-1,2,4-triazole hydrochloride (4) with 3-methyl-4-formyl-2-furoxan (2) to obtain the final product 3-amino-5-(3-methyl-4-furoxanyl)-methylenehydrazino)-1,2,4-triazole (5),

[0013]

[0014] Preferably, in step (1), the molar ratio of trans-crotonaldehyde to sodium nitrite is 1:4.

[0015] Preferably, in step (1), the reaction is carried out in the presence of glacial acetic acid as a solvent, the reaction temperature is room temperature, and the reaction time is more than 12 hours.

[0016] Preferably, in step (2), the molar ratio of 3,5-diaminotriazole to sodium nitrite and stannous chloride dihydrate is 2:1:2.

[0017] Preferably, in step (2), the reaction temperature is 80±5° C. and the reaction time is more than 2 h.

[0018] Preferably, in step (3), the molar ratio of 3-hydrazino-4-amino-1,2,4-triazole hydrochloride to 3-methyl-4-formyl-2-furoxan is 1:1.

[0019] Preferably, in step (3), the reaction is carried out in the presence of anhydrous ethanol as a solvent, the reaction temperature is reflux temperature, and the reaction time is more than 24 hours.

[0020] Compared with the prior art, the advantages of the present invention are:

[0021] (1) The reaction steps of the present invention are simple, the experimental process is safe and efficient, and meets the conditions for scale-up production.

[0022] (2) The target energetic compound obtained by the present invention has good detonation performance, and the detonation velocity of 3-amino-5-(3-methyl-4-furoxanyl)-methylenehydrazine)-1,2,4-triazole can reach 7677ms -1 The explosive pressure can reach 21.0GPa, which is similar to that of TNT. Its measured impact sensitivity is greater than that of RDX and TNT, and it has the potential to be used as a high-performance insensitive material. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is the H NMR spectrum of 3-hydrazino-4-amino-1,2,4-triazole hydrochloride.

[0024] Figure 2 This is the NMR carbon spectrum of 3-hydrazino-4-amino-1,2,4-triazole hydrochloride.

[0025] Figure 3 This is the H NMR spectrum of 3-amino-5-(3-methyl-4-furoxanyl)-methylenehydrazinyl)-1,2,4-triazole.

[0026] Figure 4 This is the NMR carbon spectrum of 3-amino-5-(3-methyl-4-furoxanyl)-methylenehydrazinyl)-1,2,4-triazole.

[0027] Figure 5 The crystal structure diagram of 3-amino-5-(3-methyl-4-furoxanyl)-methylenehydrazinyl)-1,2,4-triazole. DETAILED DESCRIPTION

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

[0029] Embodiment 1:

[0030] Trans-crotonaldehyde (5.91 ml, 71 mmol) was added to glacial acetic acid (20 ml), and an aqueous solution of NaNO2 (17.2 g, 0.285 mmol) (100 ml) was added. The resulting solution was stirred at 25°C for 12 h. The reaction mixture was neutralized with NaHCO3 and extracted three times with CH2Cl2. The organic phases were combined, washed with saturated NaCl solution, dried over anhydrous magnesium sulfate, concentrated, and then recrystallized from petroleum ether (5 ml) and dried to provide 3-methyl-4-formyl-2-furoxan in a yield of 45%.

[0031] Example 2:

[0032] Weigh 10g (100.1mmol) of 3,5-diamino-1,2,4-triazole and add it to a three-necked round-bottom flask. Add 200ml of 10mol / L hydrochloric acid and cool it to 0℃ in an ice bath. Under stirring conditions, add 25ml of sodium nitrite solution dropwise to the hydrochloric acid solution of 3,5-amino-1,2,4-triazole to carry out diazotization reaction; weigh 22.6g (100mmol) of stannous chloride dihydrate and add it to the reaction solution within a period of not less than 1.5h to carry out the reduction reaction of the diazonium salt. Continue stirring the reaction for 1h, heat it to 80℃, filter the reaction solution hot, and introduce hydrogen chloride gas into the saturated reaction solution. A white solid precipitates; then filter it with suction, wash it with anhydrous ethanol and anhydrous methanol in turn, and dry the filter cake to obtain 11.5g of white powder with a yield of 63%. Its nuclear magnetic hydrogen spectrum and nuclear magnetic carbon spectrum are shown as follows: Figure 1 and Figure 2 .

[0033] 1 H NMR (500MHz, DMSO-d6): δ (ppm) 9.79 (s, 1H). 13 C NMR (125MHz, DMSO-d6): δ (ppm) 151.7, 150.7.C, H, N analysis (%): C2H7N6 + (115.12), calculated result: C 20.87, H6.13, N 70.00; found: C 20.88, H 6.14, N 70.02.

[0034] Example 3:

[0035] 1.89g of 3-hydrazino-4-amino-1,2,4-triazole hydrochloride was placed in a 50ml three-necked flask, 25mL of anhydrous ethanol was added, and 1.54g of 3-methyl-4-formyl-2-furoxan was added in batches under stirring. The mixture was heated to reflux and reacted for 24h. After cooling, a white precipitate was precipitated. Filtering and washing with cold ethanol gave 2.13g of a white product with a yield of 89%. Its H NMR and C NMR spectra were shown as follows: Figure 3 and Figure 4 , the crystal structure is shown in Figure 5 .

[0036] 1 H NMR (500MHz, DMSO-d6): δ (ppm) 12.71 (s, 1H), 8.25 (s, 1H), 2.40 (s, 3H). 13C NMR (125MHz, DMSO-d6): δ (ppm) 154.2, 151.5, 149.3, 131.7, 112.1, 10.1. IR (KBr): 3248.91, 2650.85, 16 89.73,1571.82,1445.39,1366.60,1120.58,989.92,984.06,849.52,816.87,789.17,699.04,654.68cm -1 .C, H, N analysis (%): C6H8N8O2 (224.08), calculated result: C 32.15, H 3.60, N 49.98; found: C 32.28, H 3.46, N 49.33.

[0037] The compound density is 1.610 g / cm 3 The BKW state equation predicts that the theoretical detonation velocity of the product is 7677m / s, and the theoretical detonation pressure is 21.0GPa, which are close to 2,4,6-trinitrotoluene (TNT, detonation velocity: 6881m / s, explosion pressure: 19.5GPa). The tested friction sensitivity is about 360N, and the impact sensitivity is greater than 40J, which is lower than TNT (352N, 15J).

Claims

1. An oxidized furazanhydrazone energetic compound, characterized in that: Has the following structure:

2. A method for synthesizing an oxidized furazanhydrazone energetic compound, characterized in that: include: (1) a step of preparing 3-methyl-4-formyl-2-furoxan (2) by reacting trans-crotonaldehyde with sodium nitrite, (2) a step of reacting 3,5-diaminotriazole with a sodium nitrite solution and stannous chloride dihydrate under hydrogen chloride gas conditions to obtain 3-hydrazino-4-amino-1,2,4-triazole hydrochloride (4), (3) a step of reacting 3-hydrazino-4-amino-1,2,4-triazole hydrochloride (4) with 3-methyl-4-formyl-2-furoxan (2) to obtain the final product 3-amino-5-(3-methyl-4-furoxanyl)-methylenehydrazino)-1,2,4-triazole (5), 3. The method according to claim 2, wherein In step (1), the molar ratio of trans-crotonaldehyde to sodium nitrite is 1:

4.

4. The method according to claim 2, wherein In step (1), the reaction is carried out in the presence of glacial acetic acid as a solvent, the reaction temperature is room temperature, and the reaction time is more than 12 hours.

5. The method according to claim 2, wherein In step (2), the molar ratio of 3,5-diaminotriazole to sodium nitrite and stannous chloride dihydrate is 2:1:

2.

6. The method according to claim 2, wherein In step (2), the reaction temperature is 80±5° C. and the reaction time is more than 2 h.

7. The method according to claim 2, wherein In step (3), the molar ratio of 3-hydrazino-4-amino-1,2,4-triazole hydrochloride to 3-methyl-4-formyl-2-furoxan is 1:

1.

8. The method according to claim 2, wherein In step (3), the reaction is carried out in the presence of anhydrous ethanol as a solvent, the reaction temperature is reflux temperature, and the reaction time is more than 24 hours.

9. Use of the oxidized furazanhydrazone energetic compound as claimed in claim 1 as an insensitive explosive.

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