Bis-nitramino fused ring energetic compound and preparation method thereof

Abstract

The invention discloses a bis-nitramino fused ring energetic compound which has excellent performance and high energy density. The invention also discloses a preparation method of the bis-nitramino fused ring energetic compound, which comprises the following steps: by taking a compound 3-amino-6-bromo-1, 2, 4-triazine as a raw material, firstly preparing 6-amino-7, 8-dihydro-8-hydroxytetrazolo [5, 1-f] [1, 2, 4] triazine, then heating and dehydrating the 6-amino-7, 8-dihydro-8-hydroxytetrazolo [5, 1-f] [1, 2, 4] triazine by a simple solvent-free method to prepare a key intermediate 6-aminotetrazolo [5, 1-f] [1, 2, 4] triazine, and finally preparing the bis-nitramino fused ring energetic compound. The dinitramino fused ring energetic compound can be efficiently synthesized in one step by nitrating the key intermediate and fuming nitric acid. According to the method, the synthesis route is greatly simplified, the atom economy is improved, and a new way is opened up for efficient preparation of a series of novel high-performance energetic materials.

Description

Technical Field

[0001] This invention relates to the field of energetic materials technology. More specifically, this invention relates to a dinitramine-fused-ring energetic compound and its preparation method. Background Technology

[0002] The development of energetic materials has always pursued higher energy density, lower sensitivity, better environmental compatibility, and more efficient synthetic methods. Among these, high-nitrogen fused-ring compounds have become important frameworks for next-generation energetic materials due to their high positive heat of formation, abundant substitution sites, and good stability. The introduction of nitramines (-NH-NO2) can significantly improve the oxygen balance and detonation performance of materials. Therefore, the synthesis of compounds possessing both high-nitrogen fused-ring frameworks and nitramines is currently a research hotspot. However, the synthesis of such complex molecules usually faces severe synthetic challenges. Traditional synthetic strategies typically follow a stepwise approach of "constructing the framework first, then introducing functional groups" or "modifying monomers first, then coupling the framework," both of which suffer from cumbersome steps, low overall yield, poor selectivity of key reactions, and insufficient stability of sensitive intermediates or the framework. Summary of the Invention

[0003] One object of the present invention is to provide a dinitramine fused-ring energetic compound with excellent performance and high energy density.

[0004] Another object of the present invention is to provide the intermediate 6-aminotetrazole[5,1- f [1,2,4] Triazine can be prepared by a simple solvent-free method to synthesize this key intermediate.

[0005] Another objective of this invention is to provide a method for preparing a dinitramine-fused-ring energetic compound, which utilizes the above-mentioned key intermediate and nitration with fuming nitric acid to achieve a one-step, efficient synthesis of the dinitramine-fused-ring energetic compound.

[0006] To achieve these objectives and other advantages according to the present invention, a dinitramine-fused-ring energetic compound is provided, having the structure of the following formula (Ⅰ): (I).

[0007] The present invention also provides a method for preparing the above-mentioned dinitramine-fused-ring energetic compound, comprising the following steps: Step 1: Using compound 3-amino-6-bromo-1,2,4-triazine as a starting material, prepare compound 6-amino-7,8-dihydro-8-hydroxytetrazol[5,1-] with the following structure (II). f [1,2,4]triazine; (II) Step 2: The compound 6-amino-7,8-dihydro-8-hydroxytetrazole[5,1- f The compound 6-aminotetrazole[5,1-]triazine was prepared by dehydration upon heating at 135 °C. f [1,2,4]triazine; (III) Step 3: Add compound 6-aminotetrazole[5,1- f [1,2,4] Triazine reacts with fuming nitric acid to synthesize compound (I) N,N'-([8,8'-bistetrazole[5,1- f [1,2,4]triazine]-6,6'-dimethyl)dinitroamine.

[0008] Preferably, step one specifically includes: An aqueous solution of compound 3-amino-6-bromo-1,2,4-triazine was prepared. Sodium azide was added to the aqueous solution of compound 3-amino-6-bromo-1,2,4-triazine at a molar ratio of 10:11. The mixture was heated at 100°C for 16 h. Heating was then stopped, the reaction mixture was allowed to stand, and the solution was cooled to crystallize, yielding compound 6-amino-7,8-dihydro-8-hydroxytetrazole[5,1- f [1,2,4] Triazine.

[0009] Preferably, step two specifically includes: The compound 6-amino-7,8-dihydro-8-hydroxytetrazol[5,1- f The [1,2,4]triazine was heated in an oil bath at 135°C for 1 hour. Heating was then stopped, and the mixture was cooled to room temperature. The resulting brown solid product was collected, which was the compound 6-aminotetrazole[5,1- f [1,2,4] Triazine.

[0010] Preferably, step three specifically includes: The compound 6-aminotetrazole[5,1- f [1,2,4] Triazine was added in batches to fuming nitric acid under ice-salt bath conditions. After the addition was complete, the mixture was stirred for 1 h. The solid precipitated from the reaction was the compound of formula (Ⅰ).

[0011] The present invention has at least the following beneficial effects: This invention provides an efficient method for constructing dinitramine-fused-ring energetic compounds. This method uses fuming nitric acid as a key reagent and successfully synthesizes a high-energy-density target product with excellent performance.

[0012] This invention also breaks through the key intermediate 6-amino-tetrazole[5,1- f The synthesis of triazine [1,2,4] can be efficiently prepared through a simple solvent-free heating step, laying an important foundation for the practicality of the entire synthetic route.

[0013] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0014] Figure 1 This is a single-crystal structure diagram of compound 4·2H2O in Example 1 of the present invention; Figure 2 The image shows the carbon NMR spectrum of compound 4 in Example 1 of this invention. Figure 3 This is the DSC diagram of compound 4 in Example 1 of the present invention. Detailed Implementation

[0015] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0016] It should be noted that, unless otherwise specified, the experimental methods described in the following implementation plan are all conventional methods, and the reagents and materials described are all commercially available unless otherwise specified.

[0017] <Example 1> The dinitramine-fused-ring energetic compound has the structure of formula (Ⅰ): (I).

[0018] The specific synthesis route is as follows: The synthesis steps are as follows: Step 1: Compound 3-amino-6-bromo-1,2,4-triazine (compound 1) was reacted with sodium azide to synthesize compound 6-amino-7,8-dihydro-8-hydroxytetrazol[5,1- f [1,2,4] Triazine (compound 2); Specifically, 10.0 mmol (1.75 g) of 3-amino-6-bromo-1,2,4-triazine was mixed with 50.0 mL of water, followed by the addition of 11.0 mmol of sodium azide (0.65 g). The mixture was then heated at 100 °C for 16 h. Heating was stopped, the reaction mixture was allowed to stand, and then cooled to crystallize, yielding a brownish-yellow solid, 6-amino-7,8-dihydro-8-hydroxytetrazole[5,1- f[1,2,4] Triazine (0.90 g, 58.1%).

[0019] Step 2: The compound 6-amino-7,8-dihydro-8-hydroxytetrazole[5,1- f [1,2,4]triazine (compound 2) was dehydrated by heating at 135 °C to prepare compound 6-aminotetrazole[5,1- f [1,2,4] Triazine (compound 3); Specifically, 5.0 mmol (0.78 g) of compound 2 was placed in a 50 mL round-bottom flask, heated in an oil bath to 135 °C, and reacted for 1 h. Heating was then stopped and the mixture was cooled to obtain brown compound 3 (0.59 g, 86.1%).

[0020] Step 3: Add compound 6-aminotetrazole[5,1- f [1,2,4] Triazine (compound 3) reacts with fuming nitric acid to synthesize compound (I) N,N'-([8,8'-bistetrazole[5,1- f [1,2,4]triazine]-6,6'-diyl)dinitroamine (compound 4); Specifically, under ice-salt bath conditions (-5 °C), 0.14 g (1.0 mmol) of compound 3 was added in portions to 4.0 mL of fuming nitric acid, and the mixture was stirred for 1 h after the addition was complete. After the reaction was completed, a large amount of solid precipitated during the drying process with an airflow. The solid was filtered, washed with nitric acid, and yielded an orange solid compound 4 (0.17 g, 47.0%).

[0021] The single-crystal structure diagram of compound 4 is shown below. Figure 1 See the NMR spectrum. Figure 2 IR (cm) −1 ) ν˜ =3518, 3227,1594, 1570, 1525, 1464, 1429, 1278, 1239, 1091, 1022, 897, 795, 684, 638,561, 505, 414. 13 C NMR (Acetone-d6): δ 138.8, 152.7, 154.7 ppm; EA (C6H2N 16 O4,362.19): Calcd, calcd C19.90, H 0.56, N 61.88; found C 19.79, H 0.65, N61.98.

[0022] <Example 2> Performance comparison of the energetic compound 4 synthesized in this embodiment of the invention with existing explosives RDX and HMX: The performance comparison of compound 4 with RDX and HMX is shown in Table 1 below: Table 1: Test and computational performance of compound 4, RDX, and HMX Note: a Thermal decomposition temperature (DSC, 5 °C min) -1 ), b The density of the anhydrous compound (25°C) was measured using the gas specific gravity bottle method. c Calculated enthalpy of formation, d Calculated detonation velocity, e Calculated detonation pressure, f Impact sensitivity was tested using the standard BAM falling weight method. g Friction sensitivity was measured using a friction sensitivity meter.

[0023] The enthalpy of formation and density together determine the detonation velocity and detonation pressure. Detonation velocity and detonation pressure are key to the performance of energetic materials, and the higher the better. Impact sensitivity and friction sensitivity are key to whether the material can be used. The higher the sensitivity, the more insensitive the material, the better its stability, and the safer the material is in preparation, use and storage.

[0024] The properties of compound 4, and their comparison with existing high-performance energetic materials RDX and HMX, are shown in the table above. (Based on detonation velocity...) v and detonation pressure P The comparison shows that the density, enthalpy of formation, detonation velocity, and detonation pressure of the dinitramine fused ring energetic compound 4 all exceed those of RDX and HMX, demonstrating excellent energy performance and making it a superior high-energy-density compound.

[0025] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A dinitramine-fused-ring energetic compound, characterized in that, It has the structure of the following formula (Ⅰ): （I）。 2. The method for preparing the dinitramine-fused-ring energetic compound as described in claim 1, characterized in that, Includes the following steps: Step 1: Using compound 3-amino-6-bromo-1,2,4-triazine as a starting material, prepare compound 6-amino-7,8-dihydro-8-hydroxytetrazol[5,1-] with the following structure (II). f [1,2,4]triazine; （Ⅱ） Step 2: The compound 6-amino-7,8-dihydro-8-hydroxytetrazole[5,1- f The compound 6-aminotetrazole[5,1-]triazine was prepared by dehydration upon heating at 135 °C. f [1,2,4]triazine; （Ⅲ） Step 3: Add compound 6-aminotetrazole[5,1- f [1,2,4] Triazine reacts with fuming nitric acid to synthesize compound (I) N,N'-([8,8'-bistetrazole[5,1- f [1,2,4]triazine]-6,6'-dimethyl)dinitroamine.

3. The method for preparing the dinitramine-fused-ring energetic compound as described in claim 2, characterized in that, Step one specifically includes: An aqueous solution of compound 3-amino-6-bromo-1,2,4-triazine was prepared. Sodium azide was added to the aqueous solution of compound 3-amino-6-bromo-1,2,4-triazine at a molar ratio of 10:

11. The mixture was heated at 100°C for 16 h. Heating was then stopped, the reaction mixture was allowed to stand, and the solution was cooled to crystallize, yielding compound 6-amino-7,8-dihydro-8-hydroxytetrazol[5,1- f [1,2,4] Triazine.

4. The method for preparing the dinitramine-fused-ring energetic compound as described in claim 2, characterized in that, Step two specifically includes: The compound 6-amino-7,8-dihydro-8-hydroxytetrazol[5,1- f The [1,2,4]triazine was heated in an oil bath at 135°C for 1 hour. Heating was then stopped, and the mixture was cooled to room temperature. The resulting brown solid product was collected, which was the compound 6-aminotetrazole[5,1- f [1,2,4] Triazine.

5. The method for preparing the dinitramine-fused-ring energetic compound as described in claim 2, characterized in that, Step three specifically includes: The compound 6-aminotetrazole[5,1- f [1,2,4] Triazine was added in batches to fuming nitric acid under ice-salt bath conditions. After the addition was complete, the mixture was stirred for 1 h. The solid precipitated from the reaction was the compound of formula (Ⅰ).

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