A tetraaminobifurazan energetic compound and its preparation method

Abstract

The present invention relates to a tetraaminobifurazan energetic compound and a preparation method thereof, belonging to the technical field of energetic materials. The purpose of the present invention is to solve the problem of few amino substitution sites in the furazan skeleton in the prior art. The present invention provides a tetraaminobifurazan energetic compound and a preparation method thereof; this method uses malononitrile as a starting point to obtain 3-aminooxime-4-aminofurazan, and then obtains the target tetraamino-containing bifurazan energetic compound through a simple one-pot reaction, and there is no need to purify the intermediate. On the one hand, the present invention breaks through the number of amino groups in the current furazan-based energetic compounds and obtains a bifurazan energetic compound containing four amino groups. On the other hand, the present invention discloses a preparation method for obtaining a furazan ring skeleton compound containing multiple amino groups.

Description

Technical Field

[0001] The present invention relates to a tetraamino - bi - furazan energetic compound and a preparation method thereof, belonging to the technical field of energetic materials. Background Art

[0002] In the design and research of energetic materials, the amino group, as a very important group, can on the one hand improve the energy of energetic materials, and on the other hand endow them with good thermal stability and low mechanical sensitivity. At the same time, furazan has become an important ring skeleton that has received extensive attention in the field of energetic materials due to its characteristics of high nitrogen - oxygen content and high enthalpy of formation. Limited by the fewer substitution sites in the furazan ring, the currently synthesized energetic compounds containing the furazan - based ring skeleton contain at most two amino groups. Therefore, how to introduce multiple amino groups into furazan - based energetic compounds is a research direction with practical significance. Summary of the Invention

[0003] The purpose of the present invention is to solve the problem of fewer substitution sites in the furazan ring skeleton in the prior art. The present invention provides a tetraamino - bi - furazan energetic compound and a preparation method thereof; this method starts from malononitrile to obtain 3 - amino - oxime - 4 - amino - furazan, and then obtains the target tetraamino - bi - furazan energetic compound through a simple one - pot reaction, and there is no need to purify the intermediate. On the one hand, the present invention breaks through the number of amino groups in the current furazan - based energetic compounds and obtains a bi - furazan energetic compound containing four amino groups. On the other hand, the present invention discloses a preparation method for obtaining a furazan - ring - skeleton compound containing multiple amino groups.

[0004] The purpose of the present invention is achieved through the following technical solutions:

[0005] A tetraamino - bi - furazan energetic compound, whose structural formula is shown in Formula I:

[0006]

[0007] A preparation method for a tetraamino - bi - furazan energetic compound, comprising the following steps:

[0008] Step 1: Prepare a mixed solution of sodium nitrite in a mixture of malononitrile, glacial acetic acid in water. First, mix malononitrile with water, where the concentration of malononitrile is 1 mol / L. Then add glacial acetic acid, and the volume ratio of glacial acetic acid to water is 3:10. Cool the reaction system to 0 - 5 °C. Subsequently, add sodium nitrite, and the molar ratio of sodium nitrate to malononitrile is 1:1. During the addition of sodium nitrite, control the feeding temperature at 4 - 8 °C.

[0009] Step 2: Dissolve hydroxylamine hydrochloride in water to obtain a solution with a concentration of 1 mol / L of hydroxylamine hydrochloride. Add sodium hydroxide solution at 15 - 20°C, stir evenly, and then add the mixed solution of sodium nitrite prepared in Step 1 in malononitrile, glacial acetic acid, and water. Stir evenly at room temperature, continue stirring at 105°C for a period of time, adjust the pH to 6 - 8 after cooling, filter to obtain a solid, wash it with a large amount of water and dry it to obtain 3 - aminooxime - 4 - aminofurazan (Formula II); the volume ratio of the aqueous solution of hydroxylamine hydrochloride, sodium hydroxide solution, the mixed solution of malononitrile and glacial acetic acid in water is 9:9:5.

[0010] Step 3: Dissolve 3 - aminooxime - 4 - aminofurazan in acetonitrile, add an equimolar amount of methyl malonyl chloride, introduce ammonia gas, and adjust the pH of the solution to 9 - 10. React at high temperature for 24 h, and filter to obtain the solid as the target tetra - aminobifurazan energetic compound.

[0011]

[0012] Preferably, in Step 2, the sodium hydroxide solution is a sodium hydroxide solution with a mass fraction of 50%.

[0013] Preferably, in Step 3, the reaction temperature is 50 - 100°C.

[0014] Beneficial effects:

[0015] 1. The present invention breaks through the number of amino groups in the original furazan - based energetic compounds, forming a new type of tetra - aminobifurazan energetic compound, which can achieve the balance between stability and energy while improving the detonation performance of energetic materials. The preparation method of the synthetic tetra - aminobifurazan compound of the present invention can obtain the target energetic compound with four amino groups through a one - pot reaction with simple steps without intermediate purification.

[0016] 2. The present invention forms a bifurazan energetic compound containing four amino groups, which has the largest number of amino groups among the current furazan - based energetic compounds. Through the method of the present invention, it is possible to break through the number of amino groups in the existing furazan - based energetic compounds and achieve the synthesis of furazan - based energetic compounds containing four amino groups. Brief description of the drawings

[0017] Figure 1 It is the crystal structure diagram of the tetra - aminobifurazan energetic compound of the present invention.

[0018] Figure 2 It is the infrared spectrum diagram of the tetra - aminobifurazan energetic compound of the present invention. Detailed implementation manners

[0019] The present invention and its embodiments are described below. Such description is not restrictive, and the actual embodiments are not limited thereto. Generally speaking, if those of ordinary skill in the art are inspired by it and, without departing from the gist of the present invention, design similar structural forms and embodiments to this technical solution without creative efforts, they shall fall within the protection scope of the present invention.

[0020] Example 1: A preparation method of a tetraaminobisfurazan energetic compound

[0021] The steps of the preparation method of the target tetraaminobisfurazan energetic compound are as follows:

[0022] (1) Synthesis of 3 - aminooxime - 4 - aminofurazan

[0023] The specific synthesis route is as follows:

[0024] Add 50 mL of water into a 250 - mL round - bottom flask, then add 33 g of malononitrile into the round - bottom flask, and then add 15 mL of glacial acetic acid. Cool down to 0 °C, add 35.32 g of sodium nitrite, and control the feeding temperature at 4 - 8 °C to obtain a mixed solution of malononitrile, glacial acetic acid and water. Add 90 mL of water into a 500 - mL round - bottom flask, then add 78 g of hydroxylamine hydrochloride into the round - bottom flask. Under the condition of stirring at 15 °C, add 90 mL of a 50% sodium hydroxide solution by mass, stir for 2 h, and then dropwise add 50 mL of the mixed solution of malononitrile, glacial acetic acid and water at 5 °C for ring - closure reaction. After stirring at room temperature for 2 h, continue to stir at 105 °C for 2 h, cool down, adjust the pH to 6, filter to obtain a solid, wash it with a large amount of water and dry it to obtain 3 - aminooxime - 4 - aminofurazan.

[0025] Characterize the obtained product. Characterize the obtained product by 1H NMR and 13C NMR. 1 1H NMR(DMSO - d6,500 MHz):δ9.85,6.82,6.21, 13 13C NMR(DMSO - d6,500 MHz):δ163.41,147.34,134.84 ppm. Its molecular formula is C3H5N5O2:, and the theoretical percentage content of each element is C 25.18%, H 3.52%, N 48.94%; Elemental analysis is carried out on the product prepared in step (1) of Example 1. The test results show that the actual percentage content of each element in the product is C 25.19%, H 3.90%, N 48.13%, which is in agreement with the theoretical values.

[0026] (2) Synthesis of tetraaminobisfurazan energetic compound

[0027] Dissolve 350 mg of the synthesized 3 - aminooxime - 4 - aminofurazan in (1) in 15 mL of acetonitrile, add 340 mg of methyl malonyl chloride, introduce ammonia until pH = 8, react at 50 °C for 24 h to obtain a solid, and filter to obtain a tetra - aminobifurazan energetic compound. The crystal structure diagram of the compound is shown in the appendix Figure 1 。

[0028] Characterize the obtained product by infrared spectroscopy and single - crystal X - ray diffraction. Conduct infrared spectroscopy test, IR(KBr): 3400 3166 3275 1690 1656 1590 1531 1427 1355 1220 1012 cm-1; the crystal structure obtained by its single - crystal X - ray diffraction is shown in the appendix Figure 1 。Its molecular formula is C2H8N 10 O2: The theoretical percentage content of each element is C 28.58%, H 3.20%, N 55.54%; conduct elemental analysis on the product prepared in step (2) of Example 1. The test results show that the actual percentage content of each element in the product is C 28.69%, H 3.36%, N 55.79%, which is in agreement with the theoretical values.

[0029] Example 2: A preparation method of a tetra - aminobifurazan energetic compound

[0030] (1) Synthesis of 3 - aminooxime - 4 - aminofurazan

[0031] The specific synthesis route is as follows:

[0032] Add 50 mL of water to a 250 - mL round - bottom flask, then add 33 g of malononitrile to the round - bottom flask, subsequently add 15 mL of glacial acetic acid, cool down to 3 °C, add 35.32 g of sodium nitrite, and control the feeding temperature at 4 - 8 °C to obtain a mixed solution of malononitrile, glacial acetic acid and water; add 90 mL of water to a 500 - mL round - bottom flask, then add 78 g of hydroxylamine hydrochloride to the round - bottom flask, add 90 mL of 50% sodium hydroxide solution under stirring at 15 °C, stir for 2 h, then dropwise add 50 mL of the mixed solution of malononitrile, glacial acetic acid and water at 7 °C for ring - closing reaction. After stirring at room temperature for 2 h, continue to stir at 105 °C for 2 h, cool, adjust the pH to 7, filter to obtain a solid, wash with a large amount of water and dry to obtain 3 - aminooxime - 4 - aminofurazan.

[0033] Characterize the obtained product. Conduct 1H NMR and 13C NMR characterizations on the obtained product. 1 1H NMR(DMSO - d6, 500 MHz): δ9.85, 6.82, 6.21, 1313C NMR (DMSO-d6, 500 MHz): δ 163.41, 147.34, 134.84 ppm. Its molecular formula is C3H5N5O2, and the theoretical percentage content of each element is C 25.18%, H 3.52%, N 48.94%; for the product prepared in step (1) of Example 1, elemental analysis was carried out, and the test results showed that the actual percentage content of each element in the product was C 25.19%, H 3.90%, N 48.13%, which was in agreement with the theoretical values.

[0034] (2) Synthesis of tetraaminobifurazan energetic compound

[0035] Dissolve 350 mg of 3-aminooxime-4-aminofurazan synthesized in (1) in 15 mL of acetonitrile, add 340 mg of methyl malonyl chloride, pass ammonia gas until pH = 8, and react at 70 °C for 24 h to obtain a solid. Filter to obtain the target tetraaminobifurazan energetic compound.

[0036] The obtained product was characterized by infrared spectroscopy and single crystal X-ray diffraction. Infrared spectroscopy test was carried out, IR (KBr): 3403 3170 3279 1690 1650 1588 1529 1420 1355 1221 1015 cm-1; the crystal structure obtained by its single crystal X-ray diffraction is shown in the appendix Figure 1 Its molecular formula is C2H8N 10 O2, and the theoretical percentage content of each element is C 28.58%, H 3.20%, N 55.54%; for the product prepared in step (2) of Example 1, elemental analysis was carried out, and the test results showed that the actual percentage content of each element in the product was C 28.56%, H 3.20%, N 55.55%, which was in agreement with the theoretical values.

[0037] Example 3: A preparation method of tetraaminobifurazan energetic compound

[0038] (1) Synthesis of 3-aminooxime-4-aminofurazan

[0039] The specific synthesis route is as follows:

[0040] Add 50 mL of water to a 250 mL round-bottom flask, then add 33 g of malononitrile to the round-bottom flask, and subsequently add 15 mL of glacial acetic acid. Cool the temperature to 5 °C, add 35.32 g of sodium nitrite, and control the feeding temperature at 4 - 8 °C to obtain a mixed solution of malononitrile, glacial acetic acid, and water. Add 90 mL of water to a 500 mL round-bottom flask, then add 78 g of hydroxylamine hydrochloride to the round-bottom flask. Under the condition of stirring at 15 °C, add 90 mL of a 50% sodium hydroxide solution by mass, stir for 2 h, and then dropwise add 50 mL of the mixed solution of malononitrile, glacial acetic acid, and water at 10 °C for a ring-closing reaction. After stirring at room temperature for 2 h, continue to stir at 105 °C for 2 h, cool, adjust the pH to 8, filter to obtain a solid, wash it with a large amount of water and dry it to obtain 3-aminooxime-4-aminofurazan.

[0041] Characterize the obtained product. Perform 1H NMR and 13C NMR characterizations on the obtained product. 1 1H NMR (DMSO-d6, 500 MHz): δ 9.85, 6.82, 6.21, 13 13C NMR (DMSO-d6, 500 MHz): δ 163.41, 147.34, 134.84 ppm. Its molecular formula is C3H5N5O2. The theoretical percentage content of each element is C 25.18%, H 3.52%, N 48.94%. Perform elemental analysis on the product prepared in step (1) of Example 1. From the test results, it can be seen that the actual percentage content of each element in the product is C 25.19%, H 3.90%, N 48.13%, which is in agreement with the theoretical values.

[0042] (2) Synthesis of tetraaminobifurazan energetic compound

[0043] Dissolve 350 mg of 3-aminooxime-4-aminofurazan synthesized in (1) in 15 mL of acetonitrile, add 340 mg of methyl malonyl chloride, and pass ammonia gas until pH = 8. React at 90 °C for 24 h to obtain a solid, and filter to obtain the target tetraaminobifurazan energetic compound.

[0044] Perform infrared spectroscopy and single crystal X-ray diffraction characterizations on the obtained product. Conduct an infrared spectroscopy test, IR (KBr): 3420 3161 3277 1688 1655 1591 1530 1434 1352 1220 1011 cm-1; the crystal structure obtained from its single crystal X-ray diffraction is shown in the appendix Figure 1 . Its molecular formula is C2H8N 10O2: The theoretical percentage content of each element is C 28.58%, H 3.20%, N 55.54%; for the product prepared in step (2) of Example 1, elemental analysis was carried out, and the test results showed that the actual percentage content of each element in the product was C 28.56%, H 3.19%, N 55.57%, which was in agreement with the theoretical values.

[0045] Comparative Example 1:

[0046] 50 mL of water was added to a 250 mL round-bottom flask, then 33 g of malononitrile was added to the round-bottom flask, followed by 15 mL of glacial acetic acid. The temperature was lowered to 0 °C, and 35.32 g of sodium nitrite was added while controlling the feeding temperature at 4 - 8 °C to obtain a mixed solution of malononitrile, glacial acetic acid and water; 90 mL of water was added to a 500 mL round-bottom flask, then 78 g of hydroxylamine hydrochloride was added to the round-bottom flask, and 90 mL of 50% sodium hydroxide solution was added under stirring at 15 °C. Stir for 2 h, then dropwise add 50 mL of the mixed solution of malononitrile, glacial acetic acid and water at 5 °C for cyclization reaction. After stirring at room temperature for 2 h, continue to stir at 105 °C for 2 h, cool, adjust the pH to 8, filter to obtain a solid, wash with a large amount of water and dry to obtain 3-aminooxime-4-aminofurazan.

[0047] The obtained product was characterized. The obtained product was characterized by 1H NMR and 13C NMR. 1 1H NMR (DMSO-d6, 500 MHz): δ 9.85, 6.82, 6.21, 13 13C NMR (DMSO-d6, 500 MHz): δ 163.41, 147.34, 134.84 ppm. Its molecular formula is C3H5N5O2: The theoretical percentage content of each element is C 25.18%, H 3.52%, N 48.94%; for the product prepared in step (1) of Example 1, elemental analysis was carried out, and the test results showed that the actual percentage content of each element in the product was C 25.19%, H 3.90%, N 48.13%, which was in agreement with the theoretical values.

[0048] 350 mg of 3-aminooxime-4-aminofurazan synthesized in the previous step was dissolved in 15 mL of acetonitrile, 340 mg of methyl malonyl chloride was added, and the reaction was carried out at 30 °C for 24 h to obtain a solid, which was filtered and dried.

[0049] The obtained product was characterized by 1H NMR and 13C NMR. 1 1H NMR (DMSO-d6, 500 MHz): δ 5.40, 4.21, 3.73, 1313C NMR (DMSO-d6, 500 MHz): δ 175.98, 167.33, 161.02, 156.57, 138.19, 53.72, 33.64 ppm. The obtained solid product was characterized by infrared spectroscopy. IR (KBr): 3426 3342 2994 2967 1735 1700 1631 1614 1591 1558 1460 1441 1416 1390 1351 1291 1204 1186 1161 1151 1014 993 969 944 903 865 811 769 732 705 655 571 522 cm -1 ; It is not the target tetraaminobifurazan compound.

[0050] Comparative Example 2:

[0051] 50 mL of water was added to a 250 mL round-bottom flask, then 33 g of malononitrile was added to the round-bottom flask, and then 15 mL of glacial acetic acid was added. The temperature was lowered to 0 - 5 °C, and 35.32 g of sodium nitrite was added. The feeding temperature was controlled at 4 - 8 °C to obtain a mixed solution of malononitrile, glacial acetic acid and water; 90 mL of water was added to a 500 mL round-bottom flask, then 78 g of hydroxylamine hydrochloride was added to the round-bottom flask. Under stirring at 15 °C, 90 mL of a 50% sodium hydroxide solution by mass was added, and the mixture was stirred for 2 h. Then, at 5 - 10 °C, 50 mL of the mixed solution of malononitrile, glacial acetic acid and water was added dropwise for a ring-closing reaction. After stirring at room temperature for 2 h, the mixture was stirred at 105 °C for another 2 h, cooled, the pH was adjusted to 6 - 8, and the solid was obtained by filtration, washed with a large amount of water and dried to obtain 3-aminooxime-4-aminofurazan.

[0052] The obtained product was characterized. The obtained product was characterized by 1H NMR and 13C NMR. 1 1H NMR (DMSO-d6, 500 MHz): δ 9.85, 6.82, 6.21, 13 13C NMR (DMSO-d6, 500 MHz): δ 163.41, 147.34, 134.84 ppm. Its molecular formula is C3H5N5O2, and the theoretical percentage content of each element is C 25.18%, H 3.52%, N 48.94%; Elemental analysis was performed on the product prepared in step (1) of Example 1. The test results show that the actual percentage content of each element in the product is C 25.19%, H 3.90%, N 48.13%, which is in agreement with the theoretical values.

[0053] Dissolve 350 mg of the synthesized 3 - aminooxime - 4 - aminofurazan in the previous step in 15 mL of acetonitrile, add 340 mg of methyl malonyl chloride, and react at 25 °C for 24 h to obtain a solid. After filtration, dry it.

[0054] Characterize the obtained product by 1H NMR and 13C NMR. 1 1H NMR (DMSO - d6, 500 MHz): δ 5.47, 4.19, 3.77, 13 13C NMR (DMSO - d6, 500 MHz): δ 175.96, 167.32, 161.13, 156.57, 138.21, 53.71, 33.70 ppm. Characterize the obtained solid product by infrared spectroscopy. IR (KBr): 3425 3338 2986 2962 1731 1694 1637 1610 1590 1553 1462 1437 1402 1390 1349 1292 1206 1184 1166 1157 1017 993 967 940 904 867 810 760 734 703 650 577 527 cm -1 ; It is not the target tetra - aminobifurazan compound.

[0055] The above - mentioned specific description further details the purpose, technical solution, and beneficial effects of the invention. It should be understood that the above - mentioned is only a specific embodiment of the present invention and is not used to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A tetraaminobifurazan energetic compound, characterized in that: Its structural formula is shown in Formula I:

2. A method for preparing the tetraaminobifurazan energetic compound as claimed in claim 1, characterized in that: It includes the following steps: Step 1: Prepare a mixed solution of sodium nitrite in malononitrile and glacial acetic acid in water. First, mix malononitrile with water, where the concentration of malononitrile is 1 mol / L, then add glacial acetic acid, and the volume ratio of glacial acetic acid to water is 3:

10. Cool the reaction system to 0 - 5 °C, and then add sodium nitrite. The molar ratio of sodium nitrite to malononitrile is 1:

1. During the addition of sodium nitrite, control the feeding temperature at 4 - 8 °C; Step 2: Dissolve hydroxylamine hydrochloride in water, with the solution concentration of hydroxylamine hydrochloride being 1 mol / L. Add sodium hydroxide solution at 15 - 20 °C, stir evenly, and then add the mixed solution of sodium nitrite in malononitrile, glacial acetic acid and water prepared in Step 1. Stir evenly at room temperature, continue to stir for a period of time at 105 °C, adjust the pH to 6 - 8 after cooling, filter to obtain a solid, wash it with a large amount of water and dry it to obtain 3 - aminooxime - 4 - aminofurazan; the volume ratio of the aqueous solution of hydroxylamine hydrochloride, sodium hydroxide solution, the mixed solution of malononitrile and glacial acetic acid in water is 9:9:5; Step 3: Dissolve 3 - aminooxime - 4 - aminofurazan in acetonitrile, add an equimolar amount of methyl malonyl chloride, introduce ammonia gas, adjust the pH of the solution to 9 - 10, react completely at high temperature, and filter to obtain a solid, which is the target tetra - aminobifurazan energetic compound; the molar ratio of 3 - aminooxime - 4 - aminofurazan to methyl malonyl chloride is 1:

1.

3. The method according to claim 2, wherein: The sodium hydroxide solution described in Step 2 is a sodium hydroxide solution with a mass fraction of 50%.

4. The method according to claim 2, wherein: The high temperature described in Step 3 is 50 - 100 °C.

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