[1, 2, 5] oxadiazole [1, 2, 4] triazole explosive and preparation method thereof
By constructing a cyclic structure of [1,2,5]oxadiazole and [1,2,4]triazole through flexible imino bridging, a high-energy, low-sensitivity [1,2,5]oxadiazole-[1,2,4]triazole explosive was prepared, solving the balance problem between energy and safety, achieving a balance between high energy density and low sensitivity, and exhibiting excellent detonation velocity and detonation pressure performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- INST OF CHEM MATERIAL CHINA ACADEMY OF ENG PHYSICS
- Filing Date
- 2026-01-08
- Publication Date
- 2026-05-12
AI Technical Summary
Existing chain explosives struggle to achieve a balance between energy and safety, and lack high-energy, low-sensitivity compound designs.
By constructing a cyclic structure of [1,2,5]oxadiazole and [1,2,4]triazole through flexible imino bridging, N3,N4 bis(5-nitro-1H-1,2,4-triazol-3-yl)-1,2,5-oxadiazole-3,4-diamine was prepared as a high-energy, low-sensitivity [1,2,5]oxadiazole-[1,2,4]triazole explosive.
It achieves a balance between high energy density and low sensitivity, exhibits excellent detonation velocity and detonation pressure, has a density higher than TNT, energy comparable to RDX, a simple synthesis method, and readily available raw materials.
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Figure CN122010921A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a cascade explosive and its preparation method, specifically to a [1,2,5]oxadiazole combined with [1,2,4]triazole explosive and its preparation method, belonging to the field of energetic material preparation technology. Background Technology
[0002] Linked explosives, through connecting units, can link multiple ring structures, effectively increasing the enthalpy of formation and density, and expanding multiple derivation sites, thus enriching the substrate structure of energetic materials. Generally, carbon-carbon direct bonding, azo bridging, carbon-nitrogen bridging, and alkyl bridging are the main methods, while research on linked explosives with imino bridging as the flexible center is relatively limited. However, the presence of imino groups is beneficial in two ways: firstly, it facilitates the formation of intramolecular and intermolecular hydrogen bonds, thereby enhancing weak intermolecular interactions and forming close packing to increase the compound's density; secondly, it can enhance the compound's stability by forming δ-π hyperconjugation through the lone pair electrons on nitrogen and the connected heterocycles, effectively alleviating the contradiction between energy and sensitivity. Therefore, the imino bridging strategy is one of the effective methods for obtaining high-energy, low-sensitivity energetic compounds.
[0003] In selecting the monocyclic structure for the chain explosive, considering both the safety and energy level balance of the monocyclic structure, [1,2,5]oxadiazole and [1,2,4]triazole were ultimately chosen. [1,2,5]oxadiazole has two nitrogen atoms and one oxygen atom, with a nitrogen content as high as 40%. Furthermore, the unpaired electrons on the atoms can interact through π bonds to form a conjugated structure similar to that of a benzene ring. This conjugation positively impacts the thermal stability and safety of the compound. In addition, the presence of the oxygen atom on the [1,2,5]oxadiazole ring results in a higher density and oxygen balance in its energetic framework. Compared to other monocyclic structures, [1,2,4]triazole is more stable than tetraazole and has more modifiable sites, allowing for the introduction of more energetic groups. Compared to pyrazole, which has a higher carbon content, the higher nitrogen content gives the triazole framework better energy performance. Therefore, the [1,2,4]triazole framework can effectively balance energy and sensitivity, making it one of the preferred frameworks for constructing novel low-sensitivity, high-energy explosive molecules.
[0004] In summary, constructing the tandem structure of [1,2,5]oxadiazole and [1,2,4]triazole through flexible imino center bridging can achieve a balance between energy and safety, enabling the development of novel bridging explosives with excellent overall performance. Summary of the Invention
[0005] The present invention provides a novel [1,2,5]oxadiazole combined with [1,2,4]triazole explosive.
[0006] The present invention is implemented as follows:
[0007] A [1,2,5]oxadiazole combined with [1,2,4]triazole explosive, is: N 3 N 4 Bis(5-nitro-1H-1,2,4-triazol-3-yl)-1,2,5-oxadiazol-3,4-diamine, with the following structural formula:
[0008] .
[0009] This invention also discloses a method for preparing a [1,2,5]oxadiazole combined with [1,2,4]triazole explosive, comprising:
[0010] Step 1: Synthesis of Compound 1
[0011] Using 3,4-diamino[1,2,5]oxadiazole and N-cyanodithioimine dimethyl carbonate as raw materials, the reaction was carried out in an alkaline environment. After the raw materials were completely consumed by TLC monitoring, the reaction was quenched with a small amount of crushed ice, filtered, washed, and dried to obtain N,N''-(1,2,5-oxadiazole-3,4-diyl)(Z,Z)-bis(N'-cyanoaminothioimine) dimethyl ester, namely: compound 1.
[0012] Step 2: Synthesis of Compound 2
[0013] After compound 1 was completely dissolved in a solvent, it underwent cyclization in the presence of hydrazine hydrate to obtain N. 3 N 3' -(1,2,5-oxadiazole-3,4-diyl)bis(1H-1,2,4-triazole-3,5-diamine), i.e., compound 2.
[0014] Step 3: Synthesis of Compound 3
[0015] Compound 2 was oxidized from amino groups to nitro groups under HNO3 / NaNO2 conditions. After the reaction was completed, the reaction was quenched, extracted, and the organic phases were combined. The mixture was then dried with anhydrous sodium sulfate, and the solvent was removed by rotary evaporation to obtain the target molecule --N. 3 N 4 Bis(5-nitro-1H-1,2,4-triazol-3-yl)-1,2,5-oxadiazole-3,4-diamine, i.e., compound 3.
[0016] This invention discloses a method for preparing a [1,2,5]oxadiazole combined with [1,2,4]triazole explosive, the reaction formula of which is as follows:
[0017] .
[0018] This invention discloses a [1,2,5]oxadiazole-[1,2,4]triazole explosive (compound 3) with high-energy, low-sensitivity flexible imine properties. Its structural feature is a five-membered azole ring ([1,2,5]oxadiazole and [1,2,4]triazole) as the basic skeleton, a flexible imine group as the bridging center, and amino and nitro groups as substituents. This invention provides a method for synthesizing this compound. Compound 3 disclosed in this invention possesses characteristics such as high energy, low sensitivity, excellent detonation performance, and a simple synthesis method, and has application potential in the field of cascade explosives. Attached Figure Description
[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0020] Figure 1 The molecular structure diagram of 3·H2O prepared according to an embodiment of the present invention is shown. Detailed Implementation
[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.
[0022] The following examples provide multiple methods for preparing [1,2,5]oxadiazole combined with [1,2,4]triazole explosives, specifically including the following steps:
[0023] Step 1: Example Synthesis of Compound 1
[0024] Scheme 1: At room temperature, diaminofuran (1.00 g, 10 mmol) and N-cyanodithioimine dimethyl carbonate (3.64 g, 20 mmol) were dissolved in 10 mL of anhydrous DMF. After the products were completely dissolved, the mixture was placed in an ice-water bath to cool to 0-5 °C. Then, sodium hydride (0.80 g, 20 mmol) was added to the mixture in portions. A large amount of gas was generated immediately after the addition. The mixture was reacted in the ice bath until no more gas was generated. The ice bath was then removed, and the temperature was slowly raised to 50 °C and maintained at this temperature for 4 h. After the reaction was completed by TLC, the mixture was cooled to room temperature and the solution was poured into 100 mL of ice-water mixture. Concentrated hydrochloric acid was added dropwise while stirring to adjust the pH to 1-2. During this process, a large amount of solid was observed to form. After standing for a period of time, the mixture was filtered, washed with water (3 × 5 mL), and dried to obtain compound 1 (yield: 2.50 g, yield: 85%).
[0025] Scheme 2: At room temperature, diaminofuran (1.00 g, 10 mmol) and N-cyanodithioimine dimethyl carbonate (3.64 g, 20 mmol) were dissolved in 10 mL of anhydrous DMSO. After the products were completely dissolved, the mixture was placed in an ice-water bath to cool to 0-5 °C. Then, sodium hydride (0.80 g, 20 mmol) was added to the mixture in portions. A large amount of gas was generated immediately after the addition. The mixture was reacted in the ice bath until no more gas was generated. The ice bath was then removed, and the temperature was slowly raised to 50 °C and maintained at this temperature for 4 h. After the reaction was completed by TLC, the mixture was cooled to room temperature and the solution was poured into 100 mL of ice-water mixture. Concentrated hydrochloric acid was added dropwise while stirring to adjust the pH to 1-2. During this process, a large amount of solid was observed to form. After standing for a period of time, the mixture was filtered, washed with water (3 × 5 mL), and dried to obtain compound 1 (yield: 2.50 g, yield: 85%).
[0026] Scheme 3: At room temperature, diaminofuran (1.00 g, 10 mmol) and N-cyanodithioimine dimethyl carbonate (3.64 g, 20 mmol) were dissolved in 10 mL of anhydrous DMF. After the products were completely dissolved, the mixture was placed in an ice-water bath to cool to 0-5 °C. Then, calcium hydride (0.84 g, 20 mmol) was added to the mixture in portions. A large amount of gas was generated immediately after the addition. The mixture was reacted in the ice bath until no more gas was generated. The ice bath was then removed, and the temperature was slowly raised to 50 °C and maintained at this temperature for 4 h. After the reaction was completed by TLC, the mixture was cooled to room temperature and the solution was poured into 100 mL of ice-water mixture. Concentrated hydrochloric acid was added dropwise while stirring to adjust the pH to 1-2. During this process, a large amount of solid was observed to form. After standing for a period of time, the mixture was filtered, washed with water (3 × 5 mL), and dried to obtain compound 1 (yield: 2.50 g, yield: 85%).
[0027] The test data for compound 1 are as follows:
[0028] 1 H NMR (400 MHz, DMSO-d6): δ (ppm) 2.75 (s, 6H); 13 C NMR (100 MHz, DMSO-d6): δ (ppm) 172.83, 147.54, 113.87, 15.75; IR (KBr pellet): 3159, 3068,2927, 2212, 2188, 1629, 1593, 1548, 1518, 1431, 1390, 1339, 1300, 1243, 1120,1080, 1016, 989, 960, 818, 788, 731, 717, 688, 637, 605, 549 cm -1 HRMS (ESI) - (m / z) for C8H7N8OS2 - : 295.0190, found: 295.0186.
[0029] Step 2: Example Synthesis of Compound 2
[0030] Scheme 1: At room temperature, compound 1 (2.96 g, 10 mmol) was dispersed in 20 mL of anhydrous ethanol. Hydrazine hydrate (1.00 g, 20 mmol) was added dropwise with stirring. After the addition was complete, the mixture was heated under reflux for 8 h. After the reaction was complete, the solution was cooled to room temperature, the solid was collected by filtration, washed with anhydrous ethanol (3 × 10 mL), and dried to obtain compound 2 (yield: 2.30 g, yield: 87%).
[0031] Scheme 2: At room temperature, compound 1 (2.96 g, 10 mmol) was dispersed in 20 mL of tetrahydrofuran. Hydrazine hydrate (1.00 g, 20 mmol) was added dropwise with stirring. After the addition was complete, the mixture was heated under reflux for 8 h. After the reaction was complete, the solution was cooled to room temperature, the solid was collected by filtration, washed with anhydrous ethanol (3 × 10 mL), and dried to obtain compound 2 (yield: 2.30 g, yield: 87%).
[0032] Scheme 3: At room temperature, compound 1 (2.96 g, 10 mmol) was dispersed in 20 mL of anhydrous ethanol. Hydrazine hydrate (1.00 g, 20 mmol) was added dropwise with stirring. After the addition was complete, the mixture was reacted at room temperature for 8 h. After the reaction was complete, the solution was cooled to room temperature, the solid was collected by filtration, washed with anhydrous ethanol (3 × 10 mL), and dried to obtain compound 2 (yield: 2.30 g, yield: 87%).
[0033] The test data for compound 2 are as follows:
[0034] 1 H NMR (400 MHz, DMSO-d6): δ (ppm) 6.00 (s, 4H); 13 C NMR (100 MHz, DMSO-d6): δ (ppm) 156.98, 155.21, 145.72; IR (KBr pellet): 3599, 3433, 3287,3132, 1669, 1576, 1549, 1494, 1409, 1350, 1294, 1133, 1100, 1052, 1027, 1000,930, 848, 786, 741, 667, 610, 549 cm -1 . Elemental analysis calcd. (%) forC6H8N 12 O (264.09): C, 27.28; H, 3.05; N, 63.62; found: C, 27.15; H, 2.85; N, 63.54.
[0035] Step 3: Example Synthesis of Compound 3
[0036] Compound 2 (296 mg, 1 mmol) was dispersed in concentrated nitric acid (70%, 5 mL) under ice bath cooling at 0 °C. After stirring for 10 min, 1.5 mL of water was added dropwise to the solution, and stirring was continued for another 10 min. Subsequently, a pre-prepared sodium nitrite solution (230 mg NaNO2 - 0.5 mL water) was slowly added dropwise to the reaction mixture. After the addition was complete, the reaction was continued under ice bath cooling at 0 °C for 1 h. The reaction mixture was then slowly added dropwise to sodium nitrite solution (8.25 g NaNO2 - 80 mL water). After the addition was complete, the temperature was raised to 40 °C and maintained for 3 h. After cooling to room temperature, the filtrate was collected by filtration and extracted with ethyl acetate (3 × 30 mL). The organic phases were combined, dried over anhydrous sodium sulfate, and the solvent was removed by evaporation under reduced pressure to obtain a light yellow solid, namely compound 3 (yield: 220 mg, yield: 68%). Its hydrate structure diagram is attached. Figure 1 As shown.
[0037] The test data for compound 3 are as follows:
[0038] 1 H NMR (400 MHz, DMSO-d6): δ (ppm) 11.10 (s, 2H), 14.48 (s, 2H); 13 CNMR (100 MHz, DMSO-d6): δ (ppm) 156.98, 155.21, 145.72; IR (KBr pellet): 3229, 2157, 1619, 1598, 1566, 1526, 1508, 1397, 1311, 1239, 1137, 1076, 1053,1040, 1101, 841, 773, 703 cm -1 ; Elemental analysis calcd. (%) for C6H4N 12 O5(324.04): C, 22.23; H, 1.24; N, 51.85; found: C, 22.17; H, 1.28; N, 51.73.HRMS (ESI - (m / z) for C6H3N 12 O5 - : 323.0355, found: 323.0363.
[0039] The compound 3 prepared in the embodiments of the present invention was compared with common TNT and RDX explosives. The comparison of its physicochemical and detonation properties is shown in the table below:
[0040] Table 1. Physicochemical and detonation properties of compound 3, TNT, and RDX.
[0041] Compd. <![CDATA[T d [℃]]]> <![CDATA[ρ[g•cm -3 ]]]> <![CDATA[∆H f [kJ•mol -1 ]]> <![CDATA[D[m•s -1 ]]]> P[GPa] IS[J] FS[N] <![CDATA[3 • H2O]]> 236 1.85 647.6 8784 33.7 10 108 TNT 295 1.65 -67.0 6881 19.5 15 353 RDX 210 1.80 70.3 8795 34.9 7.4 120
[0042] As can be seen, the embodiments of the present invention have prepared a [1,2,5]oxadiazole-[1,2,4]triazole explosive with high energy density and flexible imine properties, with a density of 1.85 g•cm³. -3 ) and energy (burst velocity: 8784 m•s -1 The explosive pressure (33.7 GPa) is higher than that of TNT and comparable to that of RDX. The preparation method of compound 3 has the advantages of readily available raw materials, undemanding reaction conditions, and good overall performance, and it has the potential for application in the field of cascade explosives.
[0043] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims. It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. Furthermore, various different embodiments of the present invention can also be arbitrarily combined, as long as they do not violate the spirit of the present invention, they should also be considered as the content disclosed in the present invention.
Claims
1. A [1,2,5]oxadiazole combined with [1,2,4]triazole explosive, characterized in that: The [1,2,5]oxadiazole combined with [1,2,4]triazole explosive is: N 3 N 4 Bis(5-nitro-1H-1,2,4-triazol-3-yl)-1,2,5-oxadiazol-3,4-diamine, with the following structural formula: 。 2. The method for preparing a [1,2,5]oxadiazole combined with [1,2,4]triazole explosive as described in claim 1, characterized in that, The reaction formula is as follows: 。 3. The method for preparing a [1,2,5]oxadiazole combined with [1,2,4]triazole explosive according to claim 2, characterized in that: Step 1: Synthesis of Compound 1 Using 3,4-diamino[1,2,5]oxadiazole and N-cyanodithioimine dimethyl carbonate as raw materials, the reaction was carried out in an alkaline environment. After the raw materials were completely consumed as monitored by TLC, the reaction was quenched with a small amount of crushed ice, filtered, washed, and dried to obtain N,N''-(1,2,5-oxadiazole-3,4-diyl)(Z,Z)-bis(N'-cyanoaminothioimine) dimethyl carbonate, namely: compound 1; Step 2: Synthesis of Compound 2 After compound 1 was completely dissolved in a solvent, it underwent cyclization in the presence of hydrazine hydrate to obtain N. 3 N 3' -(1,2,5-oxadiazol-3,4-diyl)bis(1H-1,2,4-triazol-3,5-diamine), i.e., compound 2; Step 3: Synthesis of Compound 3 Compound 2 was oxidized from amino groups to nitro groups under HNO3 / NaNO2 conditions. After the reaction was completed, the reaction was quenched, extracted, and the organic phases were combined. The mixture was then dried with anhydrous sodium sulfate, and the solvent was removed by rotary evaporation to obtain N. 3 N 4 Bis(5-nitro-1H-1,2,4-triazol-3-yl)-1,2,5-oxadiazole-3,4-diamine, i.e., compound 3.