Preparation method and application of 3-amino-4-azidoethoxy furazan

Abstract

The invention discloses a preparation method and application of 3-amino-4-azidoethoxy furazan, which comprises the following steps: adding 2-azidoethanol and potassium hydroxide into dichloromethane, heating to 25-30 DEG C, reacting for 15 minutes, adding 3-amino-4-nitrofurazan, heating to 35-37 DEG C, performing reflux reaction for 3-5 hours under an ultrasonic condition, and after the reaction is finished, washing, drying and concentrating under reduced pressure to obtain the 3-amino-4-azidoethoxy furazan. And carrying out recrystallization by using ethanol, so as to obtain the 3-amino-4-azidoethoxy furazan. The compound disclosed by the invention belongs to a burning rate regulator and an energetic plasticizer, has the characteristics of relatively good thermal stability, relatively low sensitivity, capability of reducing the pressure index of a propellant formula, good burning temperature effect and the like, and is mainly applied to the fields of solid propellants, propellant powder and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of energetic materials and relates to a preparation method and application of an energetic plasticizer, 3-amino-4-azidoethoxyfuroxan. Background Art

[0002] Furazan (1,2,5-oxadiazole) has been known since the second half of the 19th century. The results of nearly half a century of research have shown that the furazan ring is a very useful structural unit in the design of high-energy density compounds composed of carbon, hydrogen, oxygen and nitrogen elements. Furazan compounds have been a popular research object in the field of energetic materials in recent years. They can form a considerable variety of compounds through coupling reactions and substitution reactions. Compounds constructed with the furazan ring as the basic structural unit generally have a series of excellent properties such as high density and high formation enthalpy. These characteristics are extremely meaningful for significantly improving the energy of low-signal propellants and clean propellants. In the prior art, the synthesis method of 3-amino-4-azidoethoxyfurazan has a high reaction temperature, requires a large amount of water washing in the post-treatment, and is difficult to completely remove the solvent, which reduces the purity and yield of the product. Summary of the invention

[0003] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a method for preparing 3-amino-4-azidoethoxyfurazan and its application, so as to overcome the problems of high reaction temperature, complex post-treatment and low yield in the synthesis reaction of 3-amino-4-azidoethoxyfurazan in the prior art. The method of the present invention is a synthesis method with low reaction temperature, simple post-treatment and high yield.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve the above problems:

[0005] A method for preparing 3-amino-4-azidoethoxyfurazan is disclosed. The method uses 3-amino-4-nitrofurazan, 2-azidoethanol and potassium hydroxide as raw materials, dichloromethane as solvent, and adopts a base-catalyzed aromatic nucleophilic substitution method under ultrasonic enhancement to prepare 3-amino-4-azidoethoxyfurazan.

[0006] The present invention also includes the following technical features:

[0007] Specifically, the following steps are included:

[0008] Add 2-azidoethanol and potassium hydroxide to dichloromethane, heat to 25°C ~ 30°C, react for 15 minutes, then add 3-amino-4-nitrofuroxan, heat to 35°C ~ 37°C, reflux for 3h ~ 5h under ultrasonic conditions. After the reaction, wash with water, dry and concentrate under reduced pressure, and recrystallize with ethanol to obtain 3-amino-4-azidoethoxyfuroxan.

[0009] Specifically, the molar ratio of 3-amino-4-nitrofurazan, 2-azidoethanol, and potassium hydroxide is 1:1-1.5:1-1.5.

[0010] Specifically, the molar ratio of 3-amino-4-nitrofurazan, 2-azidoethanol, and potassium hydroxide is 1:1.2:1.2.

[0011] The 3-amino-4-azidoethoxyfurazan prepared by the 3-amino-4-azidoethoxyfurazan preparation method is used as a burning rate regulator and an energetic plasticizer in solid propellants and propellants.

[0012] Compared with the prior art, the present invention has the following technical effects:

[0013] The 3-amino-4-azidoethoxyfuroxan synthesis method of the present invention has low reaction temperature, simple post-treatment and high yield. Compared with other synthesis methods in the prior art, the reaction is carried out in a dichloromethane solvent under ultrasonic conditions, the reaction temperature is reduced to 35° C. to 37° C., the post-treatment is simpler, and the reaction yield is increased to 92%.

[0014] The 3-amino-4-azidoethoxyfuroxan compound of the present invention has the characteristics of low sensitivity, good thermal stability and high nitrogen content, and can be widely used in solid propellants, propellants and mixed explosives as a burning rate regulator and an energetic plasticizer. With GAP as a binder, 3-amino-4-azidoethoxyfuroxan and DNDA57 as energetic plasticizers, respectively, the pressure index and the combustion temperature of the propellant formula are significantly reduced compared with the DNDA57 propellant formula, and 3-amino-4-azidoethoxyfuroxan as an energetic plasticizer component has a good application in the propellant formula. DETAILED DESCRIPTION

[0015] The present invention provides a preparation method and application of 3-amino-4-azidoethoxyfurazan. The preparation method uses 3-amino-4-nitrofurazan, 2-azidoethanol and potassium hydroxide as raw materials, dichloromethane as solvent, uses a solvent with low toxicity and simple post-treatment, simplifies the reaction and post-treatment operations, and adopts ultrasonic enhancement to reduce the temperature required for the reaction and improve the reaction yield. In the synthesis of 3-amino-4-azidoethoxyfurazan, the control step is that the azidoethoxy anion formed by deprotonation of 2-azidoethanol under alkaline conditions attacks the carbon atom connected to the nitro group of the furazan ring by nucleophilic attack, and the reaction mechanism is aromatic nucleophilic substitution (Sn2). Because the electron-donating effect of the amino group at the 3-position of the furazan ring is not conducive to the nucleophilic substitution reaction of the ortho-nitro group, it is necessary to increase the reaction temperature to complete the synthesis reaction of 3-amino-4-azidoethoxyfurazan. The present invention first reacts 2-azidoethanol with potassium hydroxide for 15 minutes to accumulate 2-azidoethoxy anions of sufficient concentration, and utilizes ultrasonic cavitation and shock waves and microjets formed in the solution to improve dispersibility and promote high-frequency and high-efficiency contact of reaction sites, thereby significantly reducing the temperature required for the reaction and obtaining a higher yield.

[0016] The method comprises the following steps:

[0017] 2-Azidoethanol and potassium hydroxide are added to dichloromethane, heated to 25°C to 30°C, reacted for 15 minutes, and then 3-amino-4-nitrofurazan is added, heated to 35°C to 37°C, and refluxed for 3 to 5 hours, preferably 4 hours, after the reaction is completed, washed with water, dried, and concentrated under reduced pressure, and recrystallized from ethanol to obtain 3-amino-4-azidoethoxyfurazan. The molar ratio of 3-amino-4-nitrofurazan, 2-azidoethanol, and potassium hydroxide is 1:1 to 1.5:1 to 1.5, and preferably, the molar ratio of 3-amino-4-nitrofurazan, 2-azidoethanol, and potassium hydroxide is 1:1.2:1.2.

[0018] The structural formula of the above 3-amino-4-nitrofurazan is:

[0019]

[0020] The structural formula of 3-amino-4-azidoethoxyfuroxan is:

[0021]

[0022] The synthetic route of the preparation method of the present invention is:

[0023]

[0024] The 3-amino-4-azidoethoxyfuroxan prepared by the invention is used as a burning rate regulator and an energetic plasticizer in solid propellants and propellants.

[0025] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0026] Embodiment 1:

[0027] The present embodiment provides a method for preparing 3-amino-4-azidoethoxyfurazan. 1.04 g (0.012 mol) of 2-azidoethanol, 0.67 g (0.012 mol) of potassium hydroxide, and 40 mL of dichloromethane are added to a reaction bottle, stirred and heated to 25° C. to 30° C., reacted at this temperature for 15 minutes, and then 1.30 g (0.010 mol) of 3-amino-4-nitrofurazan is added. Under ultrasonic conditions, the temperature is stirred and heated to 35° C. to 37° C., and ultrasonic reflux reaction is performed for 4 hours. After the reaction is completed, the reaction is washed with water, dried, and concentrated under reduced pressure, and recrystallized from ethanol to obtain a white crystalline solid, i.e., 3-amino-4-azidoethoxyfurazan, 1.57 g, with a yield of 92.35%.

[0028] Structure identification:

[0029] Infrared spectrum: IR (KBr, cm -1 ),υ:3385,3326(-NH2),2962,2930(-CH2-),2103(-N3),1649,158

[0030] 0,1448,1315(-C=N),1029(-COC-)

[0031] NMR spectrum: 1 H NMR (DMSO, 500MHz), δ: 3.74~3.76(t,2H,CH2), 4.44~4.46(t,2H,CH2), 6.13(s,2H,NH2), 2.51(p,H,DMSO); 13 C NMR (DMSO, 500MHz), δ: 157.93 (NH2-C), 149.15 (CO), 71.02 (O-CH2), 49.62 (N3-CH2), 39.82~40.16 (m, C, DMSO).

[0032] Elemental analysis: Molecular formula C4H6N6O2

[0033] Theoretical value (%): C 28.24, H 3.55, N 49.40;

[0034] Found (%): C 29.93, H 3.93, N 49.01.

[0035] It was confirmed that the substance obtained by the above preparation method was 3-amino-4-azidoethoxyfuroxan, with the molecular formula being C4H6N6O2.

[0036] Embodiment 2:

[0037] The present embodiment provides a method for preparing 3-amino-4-azidoethoxyfurazan. 0.87 g (0.010 mol) of 2-azidoethanol, 0.56 g (0.010 mol) of potassium hydroxide, and 40 mL of dichloromethane are added to a reaction bottle, stirred and heated to 25° C. to 30° C., reacted at this temperature for 15 minutes, and then 1.30 g (0.010 mol) of 3-amino-4-nitrofurazan is added. Under ultrasonic conditions, the temperature is stirred and heated to 35° C. to 37° C., and ultrasonic reflux reaction is performed for 4 hours. After the reaction is completed, the reaction is washed with water, dried, and concentrated under reduced pressure, and recrystallized from ethanol to obtain a white crystalline solid, i.e., 3-amino-4-azidoethoxyfurazan, 1.35 g, with a yield of 79.4%.

[0038] Embodiment 3:

[0039] The present embodiment provides a method for preparing 3-amino-4-azidoethoxyfurazan. 1.30 g (0.015 mol) of 2-azidoethanol, 0.84 g (0.015 mol) of potassium hydroxide, and 40 mL of dichloromethane are added to a reaction bottle, stirred and heated to 25° C. to 30° C., reacted at this temperature for 15 minutes, and then 1.30 g (0.010 mol) of 3-amino-4-nitrofurazan is added. Under ultrasonic conditions, the temperature is stirred and heated to 35° C. to 37° C., and ultrasonic reflux reaction is performed for 4 hours. After the reaction is completed, the reaction is washed with water, dried, and concentrated under reduced pressure, and recrystallized from ethanol to obtain a white crystalline solid, i.e., 3-amino-4-azidoethoxyfurazan, 1.52 g, with a yield of 89.41%.

[0040] Embodiment 4:

[0041] The present embodiment provides a method for preparing 3-amino-4-azidoethoxyfurazan. 0.70 g (0.008 mol) of 2-azidoethanol, 0.45 g (0.008 mol) of potassium hydroxide, and 40 mL of dichloromethane are added to a reaction bottle, stirred and heated to 25° C. to 30° C., reacted at this temperature for 15 minutes, and then 1.30 g (0.010 mol) of 3-amino-4-nitrofurazan is added. Under ultrasonic conditions, the temperature is stirred and heated to 35° C. to 37° C., and ultrasonic reflux reaction is performed for 4 hours. After the reaction is completed, the reaction is washed with water, dried, and concentrated under reduced pressure, and recrystallized from ethanol to obtain a white crystalline solid, i.e., 3-amino-4-azidoethoxyfurazan, 1.13 g, with a yield of 66.47%.

[0042] Application of 3-amino-4-azidoethoxyfuroxan of the present invention:

[0043] The 3-amino-4-azidoethoxyfuroxan compound of the invention has the characteristics of low sensitivity, good thermal stability and high nitrogen content, and can be used as a burning rate regulator and an energetic plasticizer and is widely used in solid propellants, propellants and mixed explosives.

[0044] With GAP as binder, 3-amino-4-azidoethoxyfuroxan and DNDA57 as energetic plasticizers, the propellant formula was designed and the performance simulation calculation was carried out. The energetic plasticizer and GAP mixed system accounted for 20.8% of the total formula mass. The formula calculation results are shown in the table. According to the calculation results, the pressure index and combustion temperature of 3-amino-4-azidoethoxyfuroxan as an energetic plasticizer in the propellant formula are significantly lower than those of DNDA57 propellant formula, indicating that 3-amino-4-azidoethoxyfuroxan can be used as an energetic plasticizer component in the propellant formula.

[0045] Table 1 Propellant formulation properties of 3-amino-4-azidoethoxyfuroxan

[0046] Plasticizer + GAP (%) Curing agent (%) Al(％) AP(%) HMX(%) <![CDATA[ηB [a] ]]> <![CDATA[T / K [b] ]]> 20.8 1.2 18 60 0 0.680 3731 20.8 1.2 18 30 30 0.497 3518

[0047] In Table 1, the plasticizer is 3-amino-4-azidoethoxyfuroxan; the curing agent is TDI, H100; %, mass fraction; [a] pressure index; [b] combustion temperature (K).

[0048] Table 2 Propellant formulation performance of DNDA57

[0049] DNDA57+GAP(%) Curing agent (%) Al(％) AP(%) HMX(%) <![CDATA[ηB [a] ]]> <![CDATA[T / K [b] ]]> 20.8 1.2 18 60 0 0.708 3772 20.8 1.2 18 30 30 0.523 3620

[0050] In Table 2, the curing agent is TDI, H100; %, mass fraction; [a] pressure index; [b] combustion temperature (K).

Claims

1. A method for preparing 3-amino-4-azidoethoxyfuroxan, characterized in that: The method uses 3-amino-4-nitrofurazan, 2-azidoethanol and potassium hydroxide as raw materials, dichloromethane as solvent, and adopts a base-catalyzed aromatic nucleophilic substitution method under ultrasound enhancement to prepare 3-amino-4-azidoethoxyfurazan.

2. The method for preparing 3-amino-4-azidoethoxyfuroxan according to claim 1, characterized in that: The following steps are involved: Add 2-azidoethanol and potassium hydroxide to dichloromethane, heat to 25°C ~ 30°C, react for 15 minutes, then add 3-amino-4-nitrofuroxan, heat to 35°C ~ 37°C, reflux for 3h ~ 5h under ultrasonic conditions. After the reaction, wash with water, dry and concentrate under reduced pressure, and recrystallize with ethanol to obtain 3-amino-4-azidoethoxyfuroxan.

3. The method for preparing 3-amino-4-azidoethoxyfuroxan according to claim 2, characterized in that: The molar ratio of 3-amino-4-nitrofurazan, 2-azidoethanol and potassium hydroxide is 1:1-1.5:1-1.

5.

4. The method for preparing 3-amino-4-azidoethoxyfuroxan according to claim 3, characterized in that: The molar ratio of 3-amino-4-nitrofurazan, 2-azidoethanol and potassium hydroxide is 1:1.2:1.

2.

5. The 3-amino-4-azidoethoxyfuroxan prepared by the 3-amino-4-azidoethoxyfuroxan preparation method according to claim 2 is used as a burning rate regulator and energetic plasticizer in solid propellants and propellants.

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