6,8-dinitroquinazoline-2,4(1h,3h)-dione energetic compounds and methods for their synthesis

Abstract

The application discloses a 6,8-dinitroquinazoline-2,4(1H,3H)-dione energetic compound and a synthesis method thereof. The structural formula of the 6,8-dinitroquinazoline-2,4(1H,3H)-dione is that 6-nitroquinazoline-2,4-diamine is subjected to nitration reaction in a nitration reagent to generate 4-amino-6,8-dinitroquinazoline-2(1H)-ketone, then the 4-amino-6,8-dinitroquinazoline-2(1H)-ketone is dissolved in an organic solvent, an alkaline solution is added, and 6,8-dinitroquinazoline-2,4(1H,3H)-dione is generated through reaction. The 6,8-dinitroquinazoline-2,4(1H,3H)-dione has good detonation performance, excellent thermal decomposition temperature and impact sensitivity and friction sensitivity, and has application potential as a heat-resistant and insensitive material.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of energetic materials, and relates to a 6,8-dinitroquinazoline-2,4(1H,3H)-dione energetic compound and a synthesis method thereof. BACKGROUND

[0002] Energetic materials as a unique branch of material science have developed rapidly in recent years. High-energy materials include explosives, propellants and fireworks. Among them, explosives with thermal decomposition temperature (onset) higher than 250℃ are defined as heat-resistant explosives. Traditional heat-resistant explosives include trisamino-trinitrobenzene (TATB), 2,2',4,4',6,6'-hexanitrodiphenyl ethylene (HNS), 3,5-dinitro-2,6-dinitroaminopyridine (PYX), 1-oxo-2,6-diamino-3,5-dinitropyrazine (LLM-105), etc. Their skeletons are mainly composed of aromatic benzene rings and six-membered nitrogen heterocycles (pyridine, pyrazine), and most of them have some defects, which cannot meet the growing demand for high-performance heat-resistant explosives. For example, HNS and PYX have relatively high thermal decomposition temperatures of 318℃ and 360℃, respectively, but their detonation performance is relatively low. Another example is 5,5'-bis(2,4,6-trinitrophenyl)-2,2'-bis(1,3,4-oxadiazole) (TKX-55) reported recently, which has relatively poor temperature resistance compared with other common heat-resistant explosives. Therefore, it is still an urgent and continuous goal to develop advanced heat-resistant explosives with high thermal stability and superior detonation performance.

[0003] Fused rings are generally considered to be polycyclic compounds formed by two or more than two carbon rings or heterocycles sharing two atoms. Fused ring compounds may have higher thermal decomposition temperatures due to their larger π conjugated systems, which have great application potential in the field of heat-resistant materials. Based on the above advantages, in recent years, the design and synthesis of fused ring energetic compounds with high thermal stability based on fused ring energetic skeletons have caused a research boom in the field. SUMMARY

[0004] The present application aims to provide a 6,8-dinitroquinazoline-2,4(1H,3H)-dione energetic compound and a synthesis method thereof.

[0005] The technical solution to achieve the purpose of the present application is as follows:

[0006] The 6,8-dinitroquinazoline-2,4(1H,3H)-dione energetic compound has the following structural formula:

[0007]

[0008] The synthesis method of the above-mentioned 6,8-dinitroquinazoline-2,4(1H,3H)-dione energetic compound has the following specific steps:

[0009] (1) 6-nitroquinazoline-2,4-diamine is subjected to nitration reaction in a nitration reagent selected from a mixed system of fuming sulfuric acid and potassium nitrate, or a mixed system of potassium nitrate and 98% sulfuric acid, or a mixed system of nitric acid and sulfuric acid, to generate 4-amino-6,8-dinitroquinazolin-2(1H)-one, and the reaction formula is as follows:

[0010]

[0011] (2) 4-amino-6,8-dinitroquinazolin-2(1H)-one is dissolved in an organic solvent selected from acetonitrile or methanol, and a basic solution is added to generate 6,8-dinitroquinazolin-2,4(1H,3H)-dione, and the reaction formula is as follows:

[0012]

[0013] Preferably, in step (1), the mass ratio of potassium nitrate or nitric acid to 6-nitroquinazoline-2,4-diamine is (1-15):1.

[0014] Preferably, in step (1), in the mixed system of fuming sulfuric acid and potassium nitrate, the mass ratio of fuming sulfuric acid to potassium nitrate is (1-5):1.

[0015] Preferably, in step (1), the reaction temperature is 0-100°C, and the reaction time is 1-24h.

[0016] Preferably, in step (2), the reaction temperature is 25°C-100°C, and the reaction time is 1-24h.

[0017] Preferably, in step (2), the basic solution is selected from sodium carbonate solution, sodium hydroxide solution or sodium bicarbonate solution.

[0018] Compared with the prior art, the present application has the following advantages:

[0019] (1) The reaction steps of the present application are simple, the experimental process is safe and efficient, the raw materials are cheap and easy to obtain, the cost is low, the experimental process is safe and efficient, the yield is high, and can reach 70%;

[0020] (2) The 6,8-dinitroquinazolin-2,4(1H,3H)-dione of the present application has good detonation performance (D=7908 m s -1 , P=24.75 GPa), its thermal decomposition temperature is 325°C, which is close to that of HNS (318°C), its actual impact sensitivity and friction sensitivity (IS>40J, FS>360N) are greater than those of HNS (IS=5J, FS=240N), and it has good stability and heat resistance, and can be used as a heat-resistant insensitive material. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 H NMR chemical shifts (300 MHz, DMSO-d6, ppm): δ = 12.23 (s, 1H), 10.95 (s, 1H), 9.03 (s, 1H), 8.82 (s, 2H) ppm.

[0022] Figure 2 H NMR chemical shifts (300 MHz, DMSO-d6, ppm): δ = 12.23 (s, 1H), 10.95 (s, 1H), 9.03 (s, 1H), 8.82 (s, 2H) ppm.

[0023] Figure 3 H NMR chemical shifts (300 MHz, DMSO-d6, ppm): δ = 12.23 (s, 1H), 10.95 (s, 1H), 9.03 (s, 1H), 8.82 (s, 2H) ppm.

[0024] Figure 4 H NMR chemical shifts (300 MHz, DMSO-d6, ppm): δ = 12.23 (s, 1H), 10.95 (s, 1H), 9.03 (s, 1H), 8.82 (s, 2H) ppm.

[0025] Figure 5 H NMR chemical shifts (300 MHz, DMSO-d6, ppm): δ = 12.23 (s, 1H), 10.95 (s, 1H), 9.03 (s, 1H), 8.82 (s, 2H) ppm. DETAILED DESCRIPTION

[0026] The application will be further described below with reference to specific examples and the accompanying drawings.

[0027] In the following examples, 6-nitroquinazoline-2,4-diamine was prepared according to the existing literature (Design, synthesis and cytotoxic evaluation of quinazoline-2,4,6-triamine and 2,6-diaminoquinazolin-4(3H)-one derivatives).

[0028] Example 1

[0029] (1) 6-nitroquinazoline-2,4-diamine (2.05 g, 10 mmol) was dissolved in 16 mL of fuming sulfuric acid at room temperature, and KNO3(6.634 g 65.62 mmol) was added. The reaction was carried out at 70 °C for 6 h, quenched with ice water, filtered, and dried at room temperature to obtain 4-amino-6,8-dinitroquinazolin-2(lH)-one as a yellow solid 1.57 g, yield 62.5%.

[0030] 1 H NMR chemical shifts (300 MHz, DMSO-d6, ppm): δ = 12.23 (s, 1H), 10.95 (s, 1H), 9.03 (s, 1H), 8.82 (s, 2H) ppm. 13C NMR chemical shifts (75 MHz, DMSO-d6, ppm): δ = 160.15, 155.37, 148.88, 143.37, 139.13, 134.46, 124.83, 118.37 ppm. IR (KBr, cm -1 ): 3174.28, 3092.94, 2824.41, 1624.68, 1495.72, 1343.65, 1241.35, 1083.92, 922.78, 760.08, 692.74, 618.88. Elemental analysis calcd (%) for C8H5N5O5 (251.16): C 38.26, H 2.01, N 27.88, O 31.85. Found: C 37.94, H 2.12, N 28.01, O 31.93 %.

[0031] (2) 4-amino-6,8-dinitroquinazolin-2(lH)-one (0.25 g, 1 mmol), Na2C03(0.11 g, 1 mmol) were added to acetonitrile. The reaction mixture was continued to stir at 50 °C for 1 h. The precipitate was collected by filtration, air dried to give 6,8-dinitroquinazoline-2,4(lH,3H)-dione, yellow solid 0.176 g, yield 70 %.

[0032] 1 H NMR chemical shifts (300 MHz, DMSO-d6): δ = 8.89 (s, 1H), 8.80 (s, 1H) ppm; 13 CNMR chemical shifts (75 MHz, DMSO-d6): δ = 160.01, 155.37, 148.88, 143.37, 140.30, 134.46, 126.03 ppm. IR (KBr, cm -1 ): 3174.29, 3092.94, 2824.41, 1476.00, 1343.65, 1270.84, 1083.29, 922.78, 859.06, 789.44, 738.15, 692.74. Elemental analysis calcd (%) for C8H4N4O6 (252.14): C 38.11, H 1.60, N 22.22, O 38.07; found: C 38.26, H 1.72, N 22.78, O 37.24 %.

[0033] Comparative Example 1

[0034] This example is essentially the same as example 1, the only difference is that the fuming sulfuric acid involved in the reaction in step (1) is changed to 31.5 mL, and the rest of the reaction conditions remain unchanged. After the reaction is completed, ice water is used for quenching, no solid is precipitated, and after extraction with ethyl acetate, 0.247 g of yellow solid is obtained, yield: 9.84%.

[0035] Example 2

[0036] This example is essentially the same as example 1, the only difference is that the reaction temperature in step (1) is changed to 60°C, and the rest of the reaction conditions remain unchanged. After the reaction is completed, ice water is used for quenching, and 1.02 g of yellow solid is obtained, yield: 40.6%.

Claims

1. A process for the synthesis of 6,8-dinitroquinazoline-2,4(1H,3H)-dione energetic compound, characterized in that, The specific steps are as follows: (1) 6-nitroquinazoline-2,4-diamine is subjected to nitration reaction in a nitration reagent selected from a mixed system of fuming sulfuric acid and potassium nitrate, or a mixed system of potassium nitrate and 98% sulfuric acid, or a mixed system of nitric acid and sulfuric acid, to generate 4-amino-6,8-dinitroquinazolin-2(1H)-one, and the reaction formula is as follows: ； (2) 4-amino-6,8-dinitroquinazolin-2(1H)-one is dissolved in an organic solvent selected from acetonitrile or methanol, and a basic solution is added to generate 6,8-dinitroquinazolin-2,4(1H,3H)-dione by reaction, and the reaction formula is as follows: 。 2. The method of synthesis of claim 1, wherein, In step (1), the mass ratio of potassium nitrate or nitric acid to 6-nitroquinazoline-2,4-diamine is (1-15):

1.

3. The method of synthesis of claim 1, wherein, In the mixed system of fuming sulfuric acid and potassium nitrate in step (1), the mass ratio of fuming sulfuric acid to potassium nitrate is (1-5):

1.

4. The method of synthesis of claim 1, wherein, In step (1), the reaction temperature is 0-100℃, and the reaction time is 1-24h.

5. The method of synthesis of claim 1, wherein, In step (2), the reaction temperature is 25℃-100℃, and the reaction time is 1-24h.

6. The method of synthesis of claim 1, wherein, In step (2), the basic solution is selected from sodium carbonate solution, sodium hydroxide solution or sodium bicarbonate solution.

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