CN111925374A

CN111925374A - Tetrazine-furazan ring high-nitrogen energetic compound and synthetic method thereof

Info

Publication number: CN111925374A
Application number: CN201910391435.6A
Authority: CN
Inventors: 叶志文; 朱王莹
Original assignee: Nanjing University of Science and Technology
Current assignee: Nanjing University of Science and Technology
Priority date: 2019-05-13
Filing date: 2019-05-13
Publication date: 2020-11-13

Abstract

The invention relates to a tetrazine-furazan ring high nitrogen energetic compound and a synthesis method thereof, the compound is named as 4-amino-N- (3-amino- [1,2,4] triazolo [4,3-b ] [1,2,4,5- ] tetrazine) -1,2, 5-oxadiazole-3-amine, the compound 2 is dissolved in DMF, sodium hydride is added under the protection of nitrogen, the mixture is stirred for 23 to 26 minutes at room temperature, the compound 1 is added, the reaction is carried out for 38 to 42 minutes, and after the reaction is finished, the target compound is obtained through separation and column chromatography purification. According to the invention, the furazan ring is taken as a latent nitro group to be introduced into the tetrazine ring, so that the energy density and the explosion velocity of the compound can be improved, the improvement of oxygen balance is facilitated, and the method is simple and safe to operate, short in reaction time, green and environment-friendly.

Description

Tetrazine-furazan ring high-nitrogen energetic compound and synthetic method thereof

Technical Field

The invention belongs to the field of fine chemical engineering, and particularly relates to a tetrazine-furazan ring high-nitrogen energetic compound and a synthesis method thereof.

Background

Energetic materials are energy carriers and sources of life for modern weapons. In recent years, high-nitrogen energetic compounds are developed into a novel energetic material with potential application value. Most of the molecular structures of the compounds do not contain nitro groups, and the compounds have higher positive enthalpy of formation, lower sensitivity and better thermal stability. They are converted to nitrogen in chemical reactions, which can release enormous amounts of energy. The high nitrogen and low carbon hydrogen content in the structure of the high nitrogen energetic compound enables the high nitrogen energetic compound to have higher density and easily reach oxygen balance; the combustion products being predominantly environmentally friendly N₂And H is₂O and CO₂Low in content, the characteristic signal of the outlet gas product can be reduced; and most of high nitrogen energetic compoundsThe electrostatic sensitivity, impact sensitivity and friction sensitivity of the object are low. Due to the excellent performance of the high-nitrogen energetic compound, the high-nitrogen energetic compound has good application prospect in various fields of energetic materials such as low-characteristic signal propellants, smokeless pyrotechnic agents, novel high-energy insensitive explosives, gas generating agents and the like.

The existing synthetic intermediate of the high-nitrogen energetic compound is unstable, certain danger exists in the operation process, the reaction time is long, the process relates to a compound with high toxicity, and the method is not green and environment-friendly.

Disclosure of Invention

The invention aims to provide a tetrazine-furazan ring high-nitrogen energetic compound and a synthesis method thereof.

The solution for realizing the purpose of the invention is as follows: a tetrazine-furazan ring high nitrogen energy-containing compound is named as 4-amino-N- (3-amino- [1,2,4] triazolo [4,3-b ] [1,2,4,5- ] tetrazine) -1,2, 5-oxadiazole-3-amine and has the following structure:

the synthesis method of the compound comprises the following steps: dissolving the compound 2 in DMF, adding sodium hydride under the protection of nitrogen, stirring at room temperature for 25 minutes, adding the compound 1, reacting for 40 minutes, and after the reaction is finished, separating and purifying by column chromatography to obtain the target compound.

Further, the molar ratio of compound 2 to compound 1 is 2: 1.

Further, sodium hydride is used in an amount of not less than 4 times by mass of the compound 1.

Compared with the prior art, the invention has the following remarkable advantages: simple and safe operation, short reaction time and environmental protection.

Drawings

FIG. 1 is a MS spectrum of a target compound.

Detailed Description

The technical scheme of the invention is further specifically explained by the drawings and the embodiments in the specification.

The tetrazine ring is a nitrogen heterocyclic energetic skeleton containing nitrogen with the mass fraction as high as 68.3 percent, and is an effective structural unit for designing a high-energy insensitive energetic material. The furazan ring is used as a 'latent nitro' to introduce a tetrazine ring, so that the energy density and the explosion velocity of the compound can be improved, and the improvement of oxygen balance is facilitated.

Example 1

1. Synthesizing tetrazine compound through five-step reaction.

In the first step, 80ML of distilled water, 200ML of 80% hydrazine hydrate, 42g of ammonium chloride and 76.28g of guanidine hydrochloride are added into a reaction device, the temperature is raised to 98 ℃, and the reaction is carried out for 4 hours. After putting the mixture into a refrigerator for 2 hours, carrying out suction filtration, washing the mixture by ice water and carrying out vacuum drying to obtain white needle-shaped solid with the yield of 96 percent.

And step two, dissolving the product of the step 50g in 300ML distilled water, heating to 45 ℃, slowly dripping 61.7ML acetylacetone, heating to 70 ℃ after dripping, and reacting for 2 hours. Cooling to room temperature, vacuum filtering, water washing and vacuum drying to obtain light yellow powder solid with yield of 94%.

And step three, dissolving 2.7g of the product obtained in the step one in 20ML acetic acid, stirring until the solution is uniformly dispersed, raising the temperature to 40 ℃ under the condition of vigorous stirring, adding 0.83g of sodium nitrite into the system in batches, and reacting for 2 hours. After the reaction is finished, pouring the reaction solution into a proper amount of ice water for standing, filtering after a period of time, washing with water, and drying in vacuum to obtain red powdery solid with the yield of 92%.

And fourthly, adding 2.7g of the product obtained in the previous step into 30ML acetonitrile, carrying out ultrasonic oscillation until the product is uniformly dispersed, dropwise adding 0.68g of 80% hydrazine hydrate while vigorously stirring, and reacting for 30 minutes at room temperature. After the reaction is finished, carrying out suction filtration and toluene washing, concentrating the mother liquor under reduced pressure until no liquid residue exists, washing the mother liquor with toluene, and carrying out vacuum drying to obtain a dark red solid with the yield of 89%.

And a fifth step of dissolving 2.06g of the product obtained in the previous step in 30ML dilute hydrochloric acid (1mol/L), stirring to disperse uniformly, adding 2.12g of nitrile bromide, and sealing and reacting at normal temperature for 24 hours. After the reaction is finished, the mixture is filtered, washed and dried to obtain a purple brown solid with the yield of 86 percent.

2. Synthesis of 3, 4-diamino furazan

Respectively dissolving 11.5ML 40% glyoxal, 45g hydroxylamine hydrochloride and 35g urea in 50ML distilled water, slowly dropwise adding a sodium hydroxide aqueous solution (28g NaOH/80ML distilled water), heating to 105 ℃ after dropwise adding, refluxing for 2 hours, changing a reflux device into a distillation device, heating to 120 ℃, distilling for 8 hours, and then refluxing and reacting for 12 hours at 105 ℃. After the reaction is finished, naturally cooling to room temperature, separating out solid, filtering and washing, and drying in vacuum to obtain light yellow needle crystal, namely 3, 4-diamino furazan, with the yield of 67%.

3. Synthesis of the target Compound

Synthesizing the target compound by the synthesized tetrazine compound and 3, 4-diamino furazan: adding 0.541g of 3, 4-diamino furazan and DMF25ML into a 50ML three-flask, stirring at room temperature under the protection of nitrogen, and completely dissolvingAfter decomposition, NaH0.812g was added, and a large amount of gas was released and stirred for 25 minutes. Then, 0.625g of the synthesized tetrazine compound was added thereto to react for 40 minutes. In an ice-water bath, the reaction solution was poured into a beaker containing 10ML of ice water, the PH was adjusted to 1, and the beaker was placed in a refrigerator at-10 ℃ overnight. Vacuum filtering, precipitating with dark red color, washing with water, and drying the filtrate to obtain dark red solid crude product. And performing column chromatography to obtain an orange red powdery finished product with the yield of 81 percent.¹H-NMR(DMSO，500MHz):＝11.23(s，1H)，7.16(s，2H)，6.23(s，2H)；¹³C NMR(DMSO，500MHz):＝143.24，148.79，149.10，151.29，151.80.

The MS spectrum is shown in FIG. 1.

Example 2

The other steps are the same as example 1, in the synthesis of the target compound, 0.541g of 3, 4-diaminofurazan and DMF25ML are added into a 50ML three-flask, nitrogen protection is carried out at room temperature, stirring is carried out until complete dissolution is achieved, then 0.812g of NaH is added, a large amount of gas is discharged, and stirring is carried out at room temperature for 15 minutes, 25 minutes and 35 minutes. Then, 0.625g of the synthesized tetrazine compound was added thereto to react for 40 minutes. As a result, the yields were found to be 50%, 81%, and 45%, respectively. The yield was highest at 25 minutes of stirring.

Example 3

The other steps are the same as example 1, in the synthesis of the target compound, 0.541g of 3, 4-diaminofurazan and DMF25ML are added into a 50ML three-flask, nitrogen protection is carried out at room temperature, stirring is carried out until complete dissolution, then 0.812g of NaH is added, a large amount of gas is discharged, and stirring is carried out for 25 minutes. Then, 0.625g of the synthesized tetrazine compound was added, and the reaction was carried out for 30 minutes, 40 minutes and 50 minutes, with yields of 54%, 81% and 43%, respectively. The yield was highest at 40 minutes of reaction.

Claims

1. A tetrazine-furazan ring high nitrogen energy-containing compound is named as 4-amino-N- (3-amino- [1,2,4] triazolo [4,3-b ] [1,2,4,5- ] tetrazine) -1,2, 5-oxadiazole-3-amine and has the following structure:

2. a synthetic method of a tetrazine-furazan ring high-nitrogen energetic compound is characterized by comprising the following steps: dissolving the compound 2 in DMF, adding sodium hydride under the protection of nitrogen, stirring at room temperature for 23-26 min, adding the compound 1, reacting for 38-42 min, and after the reaction is finished, separating and purifying by column chromatography to obtain a target compound;

3. the method of claim 2, wherein the molar ratio of compound 2 to compound 1 is 2: 1.

4. The method of synthesis according to claim 2, wherein sodium hydride is used in an amount of not less than 4 times the mass of compound 1.