A 2-gemin-dinitropyrazine hydrazine salt compound, preparation method and application

Abstract

The present invention discloses a 2-gem-dinitropyrazine hydrazine salt compound, a preparation method and an application thereof. The structural formula of the disclosed 2-gem-dinitropyrazine hydrazine salt compound is shown in (I); the compound of the present invention has a high density, which is 1.67 g / cm 3 The density of the existing 2-dinitropyridine hydrazine salt is 1.56 g / cm 3 The 2-dinitropyrazine hydrazine salt compound of the present invention has a higher energy, with a detonation velocity of 7769m / s and a detonation pressure of 23.5GPa, while the detonation velocity of the existing 2-dinitropyridine hydrazine salt is 7438m / s and a detonation pressure of 19.6GPa. The compound of the present invention is mainly used in the field of explosives.

Description

Technical Field

[0001] The invention relates to an energetic material, in particular to a 2-gemin-dinitropyrazinehydrazine salt compound, a preparation method and application thereof as an energetic material. Background Art

[0002] The energy and stability of traditional energetic materials are contradictory, so finding compounds with higher energy, lower sensitivity and better thermal stability has become the direction of development in the energetic field. In recent years, energetic ion salts have become an important direction in the research of energetic materials. Compared with non-ionic compounds with similar structures, these compounds have the advantages of low vapor pressure, high density, high thermal stability, etc. At the same time, due to the diversity of anions and cations, the performance of the compounds can be adjusted by adjusting anions and cations, which has strong designability.

[0003] Azine compounds are ideal structural units for constructing new energetic compounds. The basic skeleton of azine compounds is a nitrogen-containing aromatic six-membered ring. On the one hand, the aromaticity makes the entire molecule more stable, thus having a lower sensitivity, being less sensitive to friction, impact and sparks, and being safer to use; on the other hand, the N atom replaces the CH group in the benzene ring, making the system have a larger formation enthalpy, a higher heat of combustion, and easier to reach oxygen balance, so that it will have higher energy when used as an energetic material. Introducing oxygen-rich groups such as geminal dinitro and trinitromethyl on the energetic skeleton can effectively increase the density and energy level of the compound.

[0004] Siping Pang et al. "Energetic Di- and Trinitromethylpyridines: Synthesis and Characterization", Molecules 2018, 23, 2 discloses the synthesis method of 2-geminal dinitropyridine hydrazine salt and its partial performance data. The structure of the compound is shown in (II):

[0005]

[0006] According to the inventor's actual measurement and calculation (using the same detection method of the present invention), the density of the compound is 1.56 g / cm 3 , the detonation velocity is 7438m / s, and the detonation pressure is 19.6GPa. However, the compound has a low density and small energy. Summary of the invention

[0007] In view of the defects or shortcomings of the prior art, the present invention provides a 2-gemin-dinitropyrazinehydrazine salt compound. The structural formula of the 2-gemin-dinitropyrazinehydrazine salt compound provided by the present invention is shown in (I):

[0008]

[0009]

[0010] The present invention also provides a method for preparing the above-mentioned 2-gemin-dinitropyrazinehydrazine salt compound. To this end, the preparation method provided by the present invention comprises:

[0011] (1) at 40 to 60° C., hydroxylamine hydrochloride, sodium acetate and 2-formaldehyde pyrazine react in a first solvent to prepare 2-formaldehyde oxime pyrazine; the first solvent is selected from ethanol, methanol and acetonitrile, or a mixture of two or more thereof;

[0012] (2) at 50-70° C., 2-formaldehyde oxime pyrazine and N2O4 react in a second solvent to prepare 2-trinitromethyl pyrazine; the second solvent is selected from acetonitrile, acetone and ethyl acetate, or a mixture of two or more thereof;

[0013] (3) At room temperature, 2-trinitromethylpyrazine and hydrazine hydrate react in a third solvent to prepare 2-dinitropyrazine hydrazine salt, wherein the third solvent is selected from methanol, ethanol and water, or a mixture of two or more thereof.

[0014] In an optional scheme, the molar ratio of 2-formaldehyde pyrazine, hydroxylamine hydrochloride and sodium acetate in step (1) is 1:1 to 2.5:1 to 2.5.

[0015] In an optional solution, the reaction time of step (1) is 1 to 2 hours.

[0016] In an optional scheme, after the reaction in step (1) is completed, the reaction mixture is cooled to room temperature, the reactant is filtered, and the filter residue is extracted and dried to obtain 2-formaldehyde oxime pyrazine.

[0017] In an optional scheme, the amount of N2O4 used in step (2) is 0.5 to 1 mL per mmol of 2-formaldehyde oxime pyrazine.

[0018] In an optional solution, the reaction time of step (2) is 2 to 4 hours.

[0019] In an optional scheme, after the reaction in step (2) is completed, the reaction mixture is cooled to room temperature to remove the remaining N2O4, and the reaction mixture is dried and separated by column chromatography to obtain 2-trinitromethylpyrazine.

[0020] In an optional scheme, the molar ratio of 2-trinitromethylpyrazine to hydrazine hydrate in step (3) is 1:4-6.

[0021] In an optional solution, the reaction time of step (3) is 3 to 4 hours.

[0022] In an optional scheme, after the reaction in step (3) is completed, the reactants are dried and recrystallized to obtain 2-dinitropyrazinehydrazine salt.

[0023] The 2-gemin-dinitropyrazine hydrazine salt compound of the present invention has a high density of 1.67 g / cm 3 The density of the existing 2-dinitropyridine hydrazine salt is 1.56 g / cm 3 The 2-gemin-dinitropyrazine hydrazine salt compound of the present invention has a higher energy, with a detonation velocity of 7769 m / s and a detonation pressure of 23.5 GPa, while the detonation velocity of the existing 2-gemin-dinitropyridine hydrazine salt is 7438 m / s and a detonation pressure of 19.6 GPa. It can be seen that the 2-gemin-dinitropyrazine hydrazine salt compound of the present invention can be used as an energetic material. DETAILED DESCRIPTION

[0024] Unless otherwise specified, the scientific and technical terms herein are understood according to the knowledge of ordinary technicians in the relevant fields. It should also be understood that the temperature and concentration involved in this article are approximate values ​​for illustrative purposes. Although methods and materials similar or equivalent to the methods and materials described herein can be used for the implementation of the present disclosure, some suitable methods and materials are described below. The publications, patent applications, patents and other references mentioned herein are partially incorporated herein by reference. If there is a conflict, this article shall prevail. In addition, the material dosage, temperature, solvent and reaction time, etc. are only exemplary and are not intended to be limited. In the specific scheme, the skilled person can use the conventional experimental period according to the disclosure of the present invention to optimize the material ratio, concentration, temperature, solvent, reactant addition order, material addition method, and product recovery involved in the method to achieve the purpose of the present invention.

[0025] The present invention uses 2-formaldehyde pyrazine as a raw material, first reacts with hydroxylamine hydrochloride to generate 2-formaldehyde oxime pyrazine, then uses N2O4 to nitrolyze to generate 2-trinitromethyl pyrazine, and finally reacts with hydrazine hydrate to generate 2-gemin-dinitropyrazine hydrazine salt. The corresponding synthetic route is as follows:

[0026]

[0027] The present invention is further described in detail below in conjunction with the examples. The raw materials and reagents used in the following examples are all commercially available products. The density of the products in the following examples is measured using an ULTRAPYC 1200 true density meter; the detonation performance is calculated using EXPLO5 v6.01 software.

[0028] Embodiment 1:

[0029] (1) Synthesis of 2-formaldehyde oxime pyrazine

[0030] 0.77g (11mmol) hydroxylamine hydrochloride, 1.65g (11mmol) sodium acetate and 60ml ethanol were mixed, and 1.08g (10mmol) 2-formaldehyde pyrazine was added under stirring, and the temperature was raised to 60°C and reacted for 2h; after the reaction was completed, it was cooled to room temperature, filtered, and the filtrate was evaporated to dryness. The obtained solid was washed with 100ml water, extracted with 50ml ethyl acetate three times, and the organic phase was dried with anhydrous sodium sulfate, filtered, and the filtrate was evaporated to dryness to obtain 1.12g of brown solid, with a yield of 91.1%;

[0031] Structure identification:

[0032] NMR spectrum: 1 H NMR (600MHz, DMSO): δ12.04(s,1H),9.00(d,1H),8.65(dd,1H),8.61(d,1H),8.14(s,1H); 13 C NMR (151MHz): δ147.76,146.94,144.31,141.75

[0033] Elemental analysis: Molecular formula C3H5N3O

[0034] Theoretical values: C 48.78, H 4.09, N 34.13

[0035] Measured values: C 48.46, H 4.37, N 34.25

[0036] Mass spectrum: (ESI) m / z: 124[M+1] +

[0037] The above structural identification data confirmed that the obtained substance was indeed 2-formaldehyde oxime pyrazine;

[0038] (2) Synthesis of 2-trinitromethylpyrazine

[0039] 492 mg of 2-formaldehyde oxime pyrazine (4 mmol) and 40 mL of acetonitrile were mixed, and 4 mL of N2O4 was added dropwise under vigorous stirring. During this process, the solid raw material gradually dissolved; then the temperature was raised to 60°C, and the reaction was carried out under condensation reflux for 2 h; after the reaction was completed, the mixture was cooled to room temperature, and the remaining N2O4 was removed by vigorous stirring to obtain a light yellow transparent liquid. The reaction liquid was evaporated to dryness, and separated by column chromatography (the eluent was dichloromethane and petroleum ether, and the volume ratio of dichloromethane to petroleum ether was 1:5) to obtain 384.7 mg of a light yellow solid with a yield of 42.0%;

[0040] Structure identification:

[0041] NMR spectrum: 1H NMR (400MHz, Chloroform): δ9.30(d,1H),8.96(d,1H),8.83–8.77(m,1H); 13 C NMR (101MHz, Chloroform): δ148.51, 145.84, 144.06 Elemental analysis: Molecular formula C5H3N5O6

[0042] Theoretical values: C 26.21, H 1.32, N 30.57

[0043] Measured values: C 26.43, H 1.16, N 31.06

[0044] Mass spectrum: (ESI) m / z: 228[M-1] - ,183[M-46] -

[0045] The above structural identification data confirmed that the obtained substance was indeed 2-trinitromethylpyrazine;

[0046] (3) Synthesis of 2-dinitropyrazine hydrazine salt

[0047] 458 mg (2 mmol) of 2-trinitromethylpyrazine and 20 mL of methanol were stirred to dissolve; 0.49 mL of 80% hydrazine hydrate (8 mmol) was slowly added dropwise to the reaction system; the mixture was reacted at room temperature for 3 h, the light yellow precipitate was filtered out, and washed with cold ethanol to obtain 302.4 mg of a light yellow solid with a yield of 70.0%.

[0048] Infrared spectrum: IR(KBr):3315,1578,1541,1475,1451,1326,1227,1142,1053,862,673cm -1

[0049] NMR spectrum: 1 H NMR(DMSO-d6): δ8.92(1H,CH),8.89(1H,CH),8.81(1H,CH),7.26(5H,N2H5 + ); 13 C NMR (DMSO-d6): δ157.2(s), 141.5(s), 139.2(s), 127.3(s), 119.1(s).

[0050] Elemental analysis: Molecular formula C5H8N6O4

[0051] Theoretical values: C 27.78, H 3.73, N 38.88

[0052] Measured values: C 27.72, H 3.80, N 38.83

[0053] The above structural identification data confirmed that the obtained substance was indeed 2-gemin-dinitropyrazinehydrazine salt.

[0054] The properties of the 2-gemin-dinitropyrazine hydrazine salt obtained in this embodiment are as follows:

[0055] (1) Physical and chemical properties: Appearance: light yellow solid; Density: 1.67g / cm 3 ;

[0056] (2) Detonation performance

[0057] Detonation velocity: Density is 1.67g / cm 3 , calculated detonation velocity is 7769m / s KJ equation

[0058] Explosion pressure: density is 1.67g / cm 3 , calculated explosion pressure is 23.5GPa KJ equation

[0059] Embodiment 2:

[0060] (1) Synthesis of 2-formaldehyde oxime pyrazine

[0061] 0.77g (11mmol) hydroxylamine hydrochloride, 1.65g (11mmol) sodium acetate and 60ml ethanol were mixed, 1.08g (10mmol) 2-formaldehyde pyrazine was added under stirring, the temperature was raised to 50°C, and the reaction was carried out for 1h; after the reaction was completed, the mixture was cooled to room temperature, filtered, and the filtrate was evaporated to dryness. The obtained solid was washed with 100ml water, extracted with 50ml ethyl acetate for 3 times, the organic phase was dried with anhydrous sodium sulfate, filtered, and the filtrate was evaporated to dryness to obtain 1.02g of brown solid with a yield of 82.6%;

[0062] (2) Synthesis of 2-trinitromethylpyrazine

[0063] 492 mg 2-formaldehyde oxime pyrazine (4 mmol) and 40 mL acetonitrile were mixed, and 3 mL N2O4 was added dropwise under vigorous stirring. During this process, the solid raw material gradually dissolved; then the temperature was raised to 50°C, and the reaction was carried out under condensation reflux for 2; after the reaction was completed, the mixture was cooled to room temperature, and the remaining N2O4 was removed by vigorous stirring to obtain a light yellow transparent liquid. The reaction liquid was evaporated to dryness, and separated by column chromatography (the eluent was dichloromethane and petroleum ether, and the volume ratio of dichloromethane and petroleum ether was 1:2) to obtain 336.2 mg of a light yellow solid with a yield of 36.7%;

[0064] (3) Synthesis of 2-dinitropyrazine hydrazine salt

[0065] 458 mg (2 mmol) of 2-trinitromethylpyrazine was mixed with 20 mL of methanol and stirred to dissolve; 0.61 mL of 80% hydrazine hydrate (10 mmol) was slowly added dropwise to the reaction system; the mixture was reacted at room temperature for 4 h, the light yellow precipitate was filtered out, and washed with cold ethanol to obtain 311.5 mg of light yellow solid with a yield of 72.1%.

Claims

1. Application of 2-geminal dinitropyrazine hydrazine salt compound as energetic material, the structural formula of the 2-geminal dinitropyrazine hydrazine salt compound is shown in (I): （I）。 2. The use according to claim 1, characterized in that: The method for preparing the 2-gemin-dinitropyrazine hydrazine salt compound according to claim 1 comprises: (1) at 40-60° C., hydroxylamine hydrochloride, sodium acetate and 2-formaldehyde pyrazine react in a first solvent to prepare 2-formaldehyde oxime pyrazine; the first solvent is selected from one or a mixture of two or more of ethanol, methanol and acetonitrile; (2) at 50-70° C., 2-formaldehyde oxime pyrazine and N2O4 react in a second solvent to prepare 2-trinitromethyl pyrazine; the second solvent is selected from acetonitrile, acetone and ethyl acetate, or a mixture of two or more thereof; (3) At room temperature, 2-trinitromethylpyrazine and hydrazine hydrate react in a third solvent to prepare 2-dinitropyrazine hydrazine salt, wherein the third solvent is selected from methanol, ethanol and water, or a mixture of two or more thereof.

3. The use according to claim 2, characterized in that: 2-formaldehyde pyrazine, hydrochloric acid in step (1) The molar ratio of hydroxylamine to sodium acetate is 1:1-2.5:1-2.

5.

4. The use according to claim 2, characterized in that: The reaction time of step (1) is 1 to 2 hours.

5. The use according to claim 2, characterized in that: After the reaction in step (1) is completed, the mixture is cooled to room temperature, the reactant is filtered, and the filtrate is extracted and dried to obtain 2-formaldehyde oxime pyrazine.

6. The use according to claim 2, characterized in that: The amount of N2O4 used in step (2) is 0.5 to 1 mL per mmol of 2-formaldehyde oxime pyrazine.

7. The use according to claim 2, characterized in that: The reaction time of step (2) is 2 to 4 hours.

8. The use according to claim 2, characterized in that: After the reaction in step (2) is completed, the mixture is cooled to room temperature to remove the remaining N2O4. The reaction solution is dried and separated by column chromatography to obtain 2-trinitromethylpyrazine.

9. The use according to claim 2, characterized in that: The molar ratio of 2-trinitromethylpyrazine to hydrazine hydrate in step (3) is 1:4-6.

10. The use according to claim 2, characterized in that: The reaction time of step (3) is 3 to 4 hours.

11. The use according to claim 2, characterized in that: After the reaction in step (3) is completed, the reactant is dried and recrystallized to obtain 2-dinitropyrazine hydrazine salt.

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