6-(4-amino-1,2,5-oxadiazole-3-yl)-1,3,5-triazine-2,4-diamine and preparation method thereof

Abstract

The invention discloses a 6-(4-amino-1,2,5-oxadiazole-3-yl)-1,3,5-triazine-2,4-diamine and a preparation method thereof, wherein the steps are as follows: A. adding cyanoguanidine to a methanol solution of 3-cyano-4-aminofurazan, vigorously stirring at room temperature, adding a methanol solution of sodium methoxide, and continuing stirring and reflux reaction; B. cooling the reaction system to room temperature after the reaction is completed, filtering, washing, and drying to obtain a target product. The target product is a new energetic material mother ring, and has three amino groups, which can be further modified into an energetic compound with diverse structures, and the method is simple to operate, has a high yield, and has engineering application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of organic energetic compounds, and in particular to 6-(4-amino-1,2,5-oxadiazole-3-yl)-1,3,5-triazine-2,4-diamine and a preparation method thereof. Background Art

[0002] 3-Cyano-4-aminofurazan has a typical furazan energetic structural unit and is an important intermediate for the synthesis of energetic materials. The reactivity of the cyano group and the amino group in the 3-cyano-4-aminofurazan molecule can be used to design and synthesize a variety of energetic compounds with excellent properties. After the cyano group is connected to the furazan ring, the electron-withdrawing effect of the furazan ring greatly improves the reactivity of the cyano group with nucleophilic reagents. It can react with hydrazine hydrate, hydroxylamine, sodium azide, malononitrile and other reagents to synthesize furazan triazole, tetrazole, oxadiazole, pyrazole and other energetic compounds with novel structures.

[0003] Currently, only one furazan triazine compound, 4-amino-3-(1,2,4-triazine-3-yl) furazan, has been reported, but there is no substituent on the triazine ring and further functionalization cannot be performed. Therefore, it is urgent to develop new furazan triazine compounds and their synthesis methods. Summary of the invention

[0004] The purpose of the present invention is to provide a 6-(4-amino-1,2,5-oxadiazole-3-yl)-1,3,5-triazine-2,4-diamine and a preparation method thereof, wherein 3-cyano-4-aminofurazan is used as a raw material, and 6-(4-amino-1,2,5-oxadiazole-3-yl)-1,3,5-triazine-2,4-diamine is prepared in a high yield by a one-step reaction.

[0005] Technical solution to achieve the purpose of the present invention:

[0006] In the first aspect, the present invention provides an energetic compound intermediate, named 6-(4-amino-1,2,5-oxadiazole-3-yl)-1,3,5-triazine-2,4-diamine, whose chemical formula is C5H6N8O and structural formula is:

[0007]

[0008] Preferably, the crystal structure of the energetic compound intermediate has the following characteristics:

[0009] Crystal system: monoclinic;

[0010] Point group: P21 / n;

[0011] Unit cell parameters: α=γ=90°, β=91.609(2)°;

[0012] Unit cell volume:

[0013] Z = 4;

[0014] Density: 1.708 g cm -3 (170K).

[0015] In a second aspect, the present invention provides a method for preparing the energetic compound intermediate according to the first aspect, comprising:

[0016] A. adding cyanoguanidine to a methanol solution of 3-cyano-4-aminofurazan, stirring vigorously at room temperature, adding a methanol solution of sodium methoxide, and continuing stirring and refluxing the reaction;

[0017]

[0018] B. After the reaction is completed, the reaction system is cooled to room temperature, filtered, washed, and dried to obtain 6-(4-amino-1,2,5-oxadiazole-3-yl)-1,3,5-triazine-2,4-diamine.

[0019] Preferably, in step A, the ratio of 3-cyano-4-aminofurazan to methanol is 1 mmol:1-3 mL.

[0020] Preferably, in step A, the molar ratio of cyanoguanidine to 3-cyano-4-aminofurazan is 1:1.

[0021] Preferably, in step A, the concentration of the methanol solution of sodium methoxide is 5 M, and the molar ratio of sodium methoxide to 3-cyano-4-aminofurazan is 1 to 2:4.

[0022] Preferably, in step A, the reflux reaction time is 6 to 12 hours.

[0023] Preferably, in step B, the detergent is methanol, acetonitrile or ethanol.

[0024] In a third aspect, the present invention provides use of the energetic compound intermediate described in the first aspect in the synthesis of insensitive and heat-resistant energetic compounds.

[0025] Preferably, the insensitive energetic compound includes N-(4-(4,6-diamino-1,3,5-triazine-2-yl)-1,2,5-oxadiazole-3-yl) nitramine nitrate, 6-(4-nitro-1,2,5-oxadiazole-3-yl)-1,3,5-triazine-2,4-diamine, 6-(4-nitro-1,2,5-oxadiazole-3-yl)-1,3,5-triazine-2,4-diamine-3-oxide, 2,6-diamino-4-(4-amino-1,2,5-oxadiazole-3-yl)-1,3,5-triazine-1-perchlorate and 6,6'-(diaza-1,2-diylbis(1,2,5-oxadiazole-4,3-diyl))bis(1,3,5-triazine-2,4-diamine).

[0026] Preferably, the heat-resistant energetic compound comprises 6,6'-(diaza-1,2-diylbis(1,2,5-oxadiazole-4,3-diyl))bis(1,3,5-triazine-2,4-diamine).

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) The target product of the present invention, 6-(4-amino-1,2,5-oxadiazole-3-yl)-1,3,5-triazine-2,4-diamine, is a new energetic material mother ring and has three amino groups, which can be further modified into energetic compounds with diverse structures.

[0029] (2) The preparation method of the present invention has only one step, and the highest yield is close to 90%. Compared with the route of synthesizing furazan triazine in the prior art, the reaction steps are shortened, the operation is simpler, and it is easy to scale up by engineering.

[0030] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings in the specification, which constitute a part of this application, are used to provide further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute improper limitations on this application.

[0032] Figure 1 The hydrogen nuclear magnetic spectrum of the target product of the present invention, 6-(4-amino-1,2,5-oxadiazole-3-yl)-1,3,5-triazine-2,4-diamine.

[0033] Figure 2 This is the carbon NMR spectrum of the target product of the present invention, 6-(4-amino-1,2,5-oxadiazole-3-yl)-1,3,5-triazine-2,4-diamine.

[0034] Figure 3This is the infrared spectrum of the target product of the present invention, 6-(4-amino-1,2,5-oxadiazole-3-yl)-1,3,5-triazine-2,4-diamine.

[0035] Figure 4 The single crystal structure diagram of the target product of the present invention, 6-(4-amino-1,2,5-oxadiazole-3-yl)-1,3,5-triazine-2,4-diamine.

[0036] Figure 5 It is a unit cell stacking diagram of the target product of the present invention, 6-(4-amino-1,2,5-oxadiazole-3-yl)-1,3,5-triazine-2,4-diamine. DETAILED DESCRIPTION

[0037] It should be noted that the terms such as "upper", "lower", "left", "right", "middle", etc. cited in this specification are only for the convenience of description and are not used to limit the scope of implementation. Changes or adjustments to their relative relationships should be regarded as the scope of implementation of this application without substantially changing the technical content.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the term "and / or" used herein includes any and all combinations of one or more of the associated listed items.

[0039] If the specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. If the manufacturers of the reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0040] As used herein, the term "about" is used to provide flexibility and imprecision associated with a given term, measurement or value. The degree of flexibility for a particular variable can be easily determined by one skilled in the art.

[0041] As used herein, the term "at least one of" is intended to be synonymous with "one or more of." For example, "at least one of A, B, and C" expressly includes only A, only B, only C, and combinations of each thereof.

[0042] Concentration, amount and other numerical data can be presented in range format herein.It should be understood that such range format is only used for convenience and simplicity, and should be flexibly interpreted as not only including the numerical value clearly described as range limit, but also including all single numerical values ​​or sub-ranges contained in the range, just as each numerical value and sub-range are clearly described.For example, the numerical range of about 1 to about 4.5 should be interpreted as not only including the limit value of 1 to about 4.5 clearly described, but also including single numerals (such as 2,3,4) and sub-ranges (such as 1 to 3,2 to 4, etc.).The same principle is applicable to the scope of only narrating a numerical value, such as "less than about 4.5", which should be interpreted as including all the above-mentioned values ​​and ranges.In addition, no matter how the breadth of the described range or feature is, this explanation should be applicable.

[0043] The present invention provides a method for preparing 6-(4-amino-1,2,5-oxadiazole-3-yl)-1,3,5-triazine-2,4-diamine, comprising the following preparation steps:

[0044] A. Dissolve 3-cyano-4-aminofurazan in methanol, the ratio of 3-cyano-4-aminofurazan to methanol is 1mmol:1-3mL. Then add cyanoguanidine, the molar ratio of cyanoguanidine to 3-cyano-4-aminofurazan is 1:1;

[0045] B. Stir vigorously at room temperature, add 5M sodium methoxide methanol solution, the ratio of sodium methoxide to 3-cyano-4-aminofurazan is 1-2mmol:4mmol, and continue stirring for 0.5h after the addition;

[0046] C. Reflux the reaction for 6 to 12 hours. After the reaction is completed, cool the reaction system to room temperature, filter, wash with methanol, acetonitrile or ethanol, and dry to obtain 6-(4-amino-1,2,5-oxadiazole-3-yl)-1,3,5-triazine-2,4-diamine.

[0047] The specific synthetic route is as follows:

[0048]

[0049] Embodiment 1:

[0050] 3-Cyano-4-aminofurazan (20 mmol, 2.2 g, CAS No.: 156463-85-3) was dissolved in 40 mL of methanol, and then 1.68 g (20 mmol) of cyanoguanidine was added; the mixture was stirred vigorously at room temperature, and 5 mmol (1 mL) of 5 M sodium methoxide methanol solution was added, and stirring was continued for 0.5 h after the addition; the mixture was refluxed for 6 h, and after the reaction was completed, the reaction system was cooled to room temperature, filtered, washed with ethanol, and dried to obtain 3.3 g of 6-(4-amino-1,2,5-oxadiazole-3-yl)-1,3,5-triazine-2,4-diamine with a yield of 85%.

[0051] Embodiment 2:

[0052] 3-Cyano-4-aminofurazan (20 mmol, 2.2 g) was dissolved in 60 mL of methanol, and then 1.68 g (20 mmol) of cyanoguanidine was added; the mixture was stirred vigorously at room temperature, and 7 mmol (1.4 mL) of 5 M sodium methoxide methanol solution was added, and stirring was continued for 0.5 h after the addition; the reaction was refluxed for 8 h. After the reaction was completed, the reaction system was cooled to room temperature, filtered, washed with methanol, and dried to obtain 3.45 g of 6-(4-amino-1,2,5-oxadiazole-3-yl)-1,3,5-triazine-2,4-diamine with a yield of 88.9%.

[0053] Embodiment 3:

[0054] 3-Cyano-4-aminofurazan (20 mmol, 2.2 g) was dissolved in 20 mL of methanol, and then 1.68 g (20 mmol) of cyanoguanidine was added; the mixture was stirred vigorously at room temperature, and 10 mmol (2 mL) of 5 M sodium methoxide methanol solution was added, and stirring was continued for 0.5 h after the addition; the reaction was refluxed for 12 h. After the reaction was completed, the reaction system was cooled to room temperature, filtered, washed with methanol, and dried to obtain 3.2 g of 6-(4-amino-1,2,5-oxadiazole-3-yl)-1,3,5-triazine-2,4-diamine with a yield of 82.5%.

[0055] The 6-(4-amino-1,2,5-oxadiazole-3-yl)-1,3,5-triazine-2,4-diamine obtained in Examples 1 to 3 was dissolved in ethyl acetate and slowly evaporated at room temperature to obtain a single crystal thereof. The single crystal was tested by X-ray single crystal diffraction. The crystal structure thereof is as follows: Figure 4 and Figure 5 Its unit cell parameters are shown below:

[0056] Crystal system: monoclinic;

[0057] Point group: P21 / n;

[0058] Unit cell parameters: α=γ=90°, β=91.609(2)°;

[0059] Unit cell volume:

[0060] Z = 4;

[0061] Density: 1.708 g cm -3 (170K).

[0062] The 6-(4-amino-1,2,5-oxadiazole-3-yl)-1,3,5-triazine-2,4-diamine obtained in Examples 1 to 3 was characterized, and the spectral data were consistent. The analysis results of the sample described in Example 1 are given below.

[0063] like Figure 1 The H NMR spectrum shown, 1 H NMR (500MHz, DMSO-d6): δ7.26, 7.04, 6.83ppm.

[0064] like Figure 2 The NMR carbon spectrum shown, 13 C NMR (DMSO-d6): δ166.67, 163.27, 156.55, 143.61ppm.

[0065] like Figure 3 Infrared spectrum shown, IR(ATR): 3479,3432,3381,3339,3119,1667,1616,1540,1460,1427,1273,1227,108 4,990,915,893,864,811,773,757,722,686,671,628,603,578,482,429cm -1 .

[0066] Elemental analysis C5H6ON8 (194.158): calculated value C 30.93, H 3.11, N 57.71%; found value C 31.01, H3.09, N 57.66%.

[0067] Embodiment 4:

[0068] The 6-(4-amino-1,2,5-oxadiazole-3-yl)-1,3,5-triazine-2,4-diamine obtained in Examples 1 to 3 is subjected to energetic derivatization using conventional methods to obtain its nitration (A), oxidation (B and C), azidation (D), ion salt (E) and azo product (F). See the following synthetic route for details:

[0069]

[0070] Their formation enthalpy was calculated by the literature method (Chem. Asian J. 2018, 13, 924–928), and then their energy performance was calculated by EXPLO5 software as shown in Table 1 below. Their decomposition temperature, density, impact and friction sensitivity were tested, and the results are also listed in the table. It can be seen that compounds A to F have an energy not lower than TNT and a sensitivity not higher than FOX-12, and are a typical class of insensitive energetic materials. According to the literature (Chem. Ber. 1968, 101, 3062–3069; Org. Process Res. Dev. 2016, 20, 683–686), the amino group on the triazine ring also has the potential for further functionalization. Therefore, the 6-(4-amino-1,2,5-oxadiazole-3-yl)-1,3,5-triazine-2,4-diamine of the present invention is an effective energetic material intermediate.

[0071] Table 1 Properties of compounds A, B, C, E, and F

[0072]

[0073] Comparative Example 1:

[0074] Dissolve 3-cyano-4-aminofurazan (20 mmol, 2.2 g) in 60 mL of methanol, then add 1.68 g (20 mmol) of cyanoguanidine; stir vigorously at room temperature, add 7 mmol (1.4 mL) of 5 M sodium methoxide methanol solution, and continue stirring for 0.5 h after addition; react at room temperature for 8 h. After the reaction is completed, no 6-(4-amino-1,2,5-oxadiazole-3-yl)-1,3,5-triazine-2,4-diamine is generated, and the reaction fails.

[0075] Therefore, the present invention adopts the above-mentioned 6-(4-amino-1,2,5-oxadiazole-3-yl)-1,3,5-triazine-2,4-diamine and its preparation method, and synthesizes a new furazan triazine compound that can be used as an intermediate of energetic materials, shortens the synthesis steps of the furazan triazine compound, improves the yield, and has engineering application prospects.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. Use of an energetic compound intermediate in the synthesis of insensitive and heat-resistant energetic compounds, characterized in that: The chemical formula of the energetic compound intermediate is C5H6N8O, and the structural formula is: The insensitive energetic compound is selected from the following structural compounds: The heat-resistant energetic compound is a compound with the following structure:

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