Synthesis method of 1, 1 '-diamino-5, 5'-bitetrazole

Abstract

The invention provides a synthesis method of 1, 1 '-diamino-5, 5'-bistetrazole, which specifically comprises the following steps: step 1, dissolving a certain amount of dioxocarbonyl-1, 1 '-diamino-5, 5'-bistetrazole in a certain amount of protonic acid; 2, at a certain temperature, refluxing the mixture obtained in the step 1 for a period of time; 3, extracting the crystal in the step 2; and 4, putting the crystal in the step 2 into water, and recrystallizing to obtain the 1, 1 '-diamino-5, 5'-bistetrazole.

Description

Technical Field

[0001] The invention belongs to the field of organic energetic materials, and in particular relates to a method for synthesizing 1,1'-diamino-5,5'-bitetrazole. Background Art

[0002] Energetic materials are an important cornerstone in the field of national defense and security. The energy of nitrogen-rich energetic compounds depends on the percentage of nitrogen. The higher the nitrogen content, the greater the energy released during the reaction. Tetrazolyl compounds are a planar ring structure skeleton with aromaticity and a nitrogen content of more than 80%. They can interact with a variety of non-covalent bonds, such as forming hydrogen bonds, coordinating with metal ions, π-π stacking, and electrostatic effects. Among the five-membered nitrogen heterocyclic energetic compounds, this compound has a higher positive heat of formation (such as the heat of formation of 5H-1,2,3,4-tetrazole is +237kJ·mol-1), as well as good stability and low sensitivity. Its main decomposition product is N2, which has excellent characteristics such as environmental friendliness. At present, tetrazolyl compounds are a hot topic in the field of high nitrogen energetic materials. They have the characteristics of high thermal stability, low carbon content, and release a large amount of gas and energy during decomposition. Due to the large electronegativity of nitrogen atoms in tetrazolyl compounds, their nitrogen-containing five-membered aromatic rings can form a delocalized large π bond of a benzene-like structure, and the electron density of nitrogen atoms is reduced, which has the property of insensitivity. Fischer et al. used sodium cyanide to react with sodium azide and manganese dioxide under acidic conditions to obtain the manganese salt of 5,5'-tetrazole, and prepared guanidine, aminoguanidine, diaminoguanidine, triaminoguanidine, carbohydrazide salt and other high nitrogen energetic ion salts of 5,5'-tetrazole. Among them, the triaminoguanidine salt of BT has a formation enthalpy of 1137kJ·mol-1, a detonation velocity of 8181m·s-1, an impact sensitivity of 15J, and a friction sensitivity of 285N, which belongs to high energy insensitive energetic materials. 1,1'-diamino-5,5'-bitetrazole, after the amino group is introduced into 5,5'-bitetrazole, has a higher nitrogen content and can decompose to produce more heat and nitrogen. At the same time, the introduction of the amino group makes it neutral or weakly alkaline. During long-term storage and use, it is non-corrosive to metal shells and enhances its own stability and solubility in water.

[0003] 1,1′-Diamino-5,5′-bistetrazole is a classic material in the bistetrazole energetic materials. In 2022, Maximilian Ben disclosed its synthesis method in "Krapcho Decarboxylation of Ethyl-Carbazates: Synthetic Approach toward 1,1′-Diamino-5,5′-bistetrazole and Its Utilization as a High Performing Metal-Free Initiator", 2022, 24(8), 1747-1751. The method synthesizes 1,1′-diamino-5,5′-bistetrazole by decarboxylation of ethyl carbamate at 130°C and LiCl catalyst. The synthesis route is as follows:

[0004] This method requires reaction in a high temperature environment and has a long reaction time. The catalyst LiCl is not environmentally friendly, and the yield of 1,1′-diamino-5,5′-tetrazolyl is low, only 31%.

[0005] In the patent number CN112125864A "A Synthesis Method of 1,1'-Diamino-5,5'-Bis(tetrazolyl)", a synthesis method is disclosed, and its synthesis path is as follows:

[0006] This method requires synthesis in a sealed environment, at 150°C-160°C and using an alkali catalyst. The operating conditions are complex, difficult to operate, and difficult to prepare. Summary of the invention

[0007] The main purpose of the present invention is to provide a method for synthesizing 1,1'-diamino-5,5'-bitetrazole, which has a higher product yield and higher purity.

[0008] To achieve the above purpose, the technical solution adopted by the present invention is: a method for synthesizing 1,1′-diamino-5,5′-bitetrazole, which specifically comprises the following steps:

[0009] Step 1, dissolving a certain amount of dioxycarbonyl-1,1′-diamino-5,5′-bitetrazolium in a certain amount of protonic acid;

[0010] Step 2: at a certain temperature, heating the mixture obtained in step 1 in water and hydrochloric acid to a certain temperature and reflux for a period of time;

[0011] Step 3, extracting the solvent after the reaction with ethyl acetate to extract the product 1,1′-diamino-5,5′-tetrazole in the solution after the reaction;

[0012] Step 4: placing the crystals in step 2 into water for recrystallization to obtain 1,1′-diamino-5,5′-bitetrazole.

[0013] Preferably, in step 1, the protonic acid comprises one or more of nitric acid, hydrochloric acid, chloric acid, hypochlorous acid, perchloric acid, and sulfuric acid.

[0014] Preferably, in step 1, the reaction time of dioxycarbonyl-1,1′-diamino-5,5′-bitetrazolium in protonic acid is 6-24 h.

[0015] Preferably, in step 2, the reflux temperature is 60-110° C., and / or the reflux time is 10-15 h.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The synthetic method of the invention has environmentally friendly selected reagents, does not require a high-temperature reaction environment, has high product yield and high purity, and the yield of the method can reach 40%, which is much higher than the existing technology; the purity of the product 1,1'-diamino-5,5'-tetrazole is above 98.6% (HPLC), and there are no difficult-to-separate by-products, and the operation process is simple, so the method is suitable for synthesizing high-purity 1,1'-diamino-5,5'-tetrazole in large quantities. DETAILED DESCRIPTION

[0018] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art may think of other obvious variations.

[0019] A method for synthesizing 1,1′-diamino-5,5′-bitetrazole, the synthetic route is as follows:

[0020]

[0021] The specific steps are as follows:

[0022] Step 1, dissolving a certain amount of dioxycarbonyl-1,1′-diamino-5,5′-bitetrazolium in a certain amount of protonic acid;

[0023] Step 2: at a certain temperature, heating the mixture obtained in step 1 in water and 1M dilute hydrochloric acid at 100°C for a period of time;

[0024] Step 3, extracting the solvent after the reaction with ethyl acetate to extract the product 1,1′-diamino-5,5′-tetrazole in the solution after the reaction;

[0025] Step 4: Put the 1,1′-diamino-5,5′-bitetrazole extracted in step 3 into water for recrystallization to obtain pure 1,1′-diamino-5,5′-bitetrazole.

[0026] Preferably, in step 1, the protonic acid comprises one or more of nitric acid, hydrochloric acid, chloric acid, hypochlorous acid, perchloric acid, and sulfuric acid, preferably hydrochloric acid.

[0027] In step 1, the reaction time of dioxycarbonyl-1,1′-diamino-5,5′-bitetrazol in proton acid is 6-24 hours.

[0028] In step 2, the reflux temperature is 60-110° C., and the reflux time is 10-15 h.

[0029] Experimental Example 1

[0030] 1.0 g of 1,1′-diamino-5,5′-tetrazole was dissolved in 2.2 mL of 1 M HCl solution, and the mixture was refluxed at 100° C. for 13 h. The resultant was extracted with ethyl acetate and recrystallized with H 2 O to obtain 1,1′-diamino-5,5′-tetrazole with a yield of 40%.

[0031] Experimental Example 2

[0032] 1.0 g of dioxycarbonyl-1,1′-diamino-5,5′-bi-tetrazole was dissolved in 4.5 ml of 1M HCl, and the mixture was refluxed at 80° C. for 15 h. The resultant was extracted with ethyl acetate and recrystallized with H 2 O to obtain 1,1′-diamino-5,5′-bi-tetrazole with a yield of 38.5%.

[0033] Experimental Example 3

[0034] 1.0 g of dioxycarbonyl-1,1′-diamino-5,5′-bi-tetrazole was dissolved in 2.2 mL of 1 M HNO3 solution, and the mixture was refluxed at 100°C for 13 h. The resultant was extracted with ethyl 1,1′-diamino-5,5′-bi-tetrazole acetate and recrystallized with H2O to obtain 1,1′-diamino-5,5′-bi-tetrazole with a yield of 38.2%.

[0035] Experimental Example 4

[0036] 1.0 g of dioxycarbonyl-1,1′-diamino-5,5′-bi-tetrazole was dissolved in 4.5 ml of 1M HNO3, and the mixture was refluxed at 110°C for 11 h. The resultant was extracted with ethyl acetate and recrystallized with H2O to obtain 1,1′-diamino-5,5′-bi-tetrazole with a yield of 37.8%.

[0037] Experimental Example 5

[0038] 1.0 g of dioxycarbonyl-1,1′-diamino-5,5′-bi-tetrazole was dissolved in 2.3 ml of 1M HClO3, and the mixture was refluxed at 60°C for 13 h. The resultant was extracted with ethyl acetate and recrystallized with H2O to obtain 1,1′-diamino-5,5′-bi-tetrazole with a yield of 37.5%.

[0039] Experimental Example 6

[0040] 1.0 g of dioxycarbonyl-1,1′-diamino-5,5′-bi-tetrazole was dissolved in 2.3 ml of 1M HClO3, and the mixture was refluxed at 80°C for 15 h. The resultant was extracted with ethyl acetate and recrystallized with H2O to obtain 1,1′-diamino-5,5′-bi-tetrazole with a yield of 38.1%.

[0041] The structure of the substance obtained in Experimental Example 1 was identified, and the identification results are as follows:

[0042] Infrared (cm-1): 3340, 3235, 3162, 1611, 1389, 1272, 1130, 1031, 991, 921, 753, 710, 691, 668, 466, 412;

[0043] 1H NMR (DMSO, δ, ppm): 7.41;

[0044] 13C NMR (DMSO, δ, ppm): 141.2;

[0045] 15N NMR (DMSO, δ, ppm): 6.2, 47.9, 133.9, 302.3.

[0046] Elemental analysis: C2H4N 10 :

[0047] Theoretical value: C (14.29%), H (2.40%), N (83.31%);

[0048] Found: C (13.99%), H (2.86%), N (83.15%).

[0049] It can be seen that 1,1′-diamino-5,5′-bitetrazole was obtained in Experimental Example 1.

[0050] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only describe the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for synthesizing 1,1′-diamino-5,5′-bitetrazole, comprising the following steps: Step 1, dissolving a certain amount of dioxycarbonyl-1,1′-diamino-5,5′-bitetrazolium in a certain amount of protonic acid; Step 2: at a certain temperature, heating the mixture obtained in step 1 in water and hydrochloric acid to a certain temperature and reflux for a period of time; Step 3, extracting the solvent after the reaction with ethyl acetate to extract the product 1,1-diamino-5,5-tetrazole in the solution after the reaction; Step 4: placing the crystals in step 2 into water for recrystallization to obtain 1,1′-diamino-5,5′-bitetrazole.

2. The method for synthesizing 1,1′-diamino-5,5′-bitetrazole according to claim 1, characterized in that: In step 1, the protonic acid includes one or more of nitric acid, hydrochloric acid, chloric acid, hypochlorous acid, perchloric acid, and sulfuric acid.

3. The method for synthesizing 1,1′-diamino-5,5′-bitetrazole according to claim 2, characterized in that: In step 1, the reaction time of dioxycarbonyl-1,1′-diamino-5,5′-bitetrazol in proton acid is 6-24 hours.

4. The method for synthesizing 1,1′-diamino-5,5′-bitetrazole according to claim 3, characterized in that: In step 2, the reflux temperature is 60-110° C., and / or the reflux time is 10-15 h.

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