- Nonmetallic Pentazole Salts Based on Furazan or 4-Nitropyrazole for Enhancing Density and Stability
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In this work, three novel nonmetallic pentazole salts (6-8) based on furazan or 4-nitropyrazole were synthesized. Some coplanar groups were introduced into the compounds to improve the planarity of the crystal packing. 4-Amino-1,2,5-oxadiazole-3-carbohydrazonamide pentazolate (6), 5-(4-amino-1,2,5-oxadiazol-3-yl)-4H-1,2,4-triazole-3,4-diamine pentazolate (7), and 5,5′-(4-nitro-1H-pyrazole-3,5-diyl)-bis(4H-1,2,4-triazole-3,4-diamine) pentazolate (8) all show more stable π-πstacking and exhibit superior thermal stability (110.5-116.4 °C) than most other reported nonmetallic pentazole salts (Tonset: 80-110 °C), and compound 8 has the highest crystal density (1.722 g·cm-3/173 K) of nonmetallic pentazole salts to date. All salts have been thoroughly characterized by NMR (1H and 13C) spectroscopy, infrared (IR), Roman (RA), and elemental analysis. The decomposition temperature of all salts displays more than 110 °C, which is measured by differential scanning calorimetry (DSC). These compounds all shows low sensitivity (IS > 35 J, FS > 360 N) measured by standard BAM methods. Glycidyl azide polymer (GAP) based propellant formula with the addition of salt 6 or 7 shows a higher specific impulse (6, Isp = 262.1 s; 7, Isp = 263.9 s) than that of RDX (Isp = 259.0 s). This study can provide a new crystal engineering way for the synthesis of pentazole salt to solve the problem of low density and poor stability.
- Chen, Jieyi,Cheng, Guangbin,Hu, Bingcheng,Hu, Wei,Sun, Chengguo,Yang, Hongwei,Zhang, Chong
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p. 2690 - 2698
(2021/05/10)
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- Based on triazole nitrogen heterocyclic energetic compounds and their synthesis methods
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The present invention discloses a triazole-based nitrogen heterocyclic energy-containing compound and a method of synthesis thereof. The energetic compound is 4-nitro-3,5-bis(3,4-diamino-1,2,4-triazole-5-yl) 1H- pyrazole. By the synthesis method of the present invention synthesized based on the actual measurement of impact sensitivity of triazole nitrogen heterocyclic energetic compounds >40J, friction sensitivity > 360N, calculated burst velocity of 8197m/s, The burst pressure is 24.2Gpa, the thermal decomposition temperature is 318.6 °C, the performance is better than TNT, the thermal decomposition temperature and sensitivity are better than RDX, and it is stable at room temperature, and its synthesis method is simple, the synthesis process is safe and controllable, it can achieve mass production, and its thermal decomposition temperature is high, and it has application prospects in the field of heat-resistant explosives.
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- Synthesis of high-performance insensitive energetic materials based on nitropyrazole and 1,2,4-Triazole
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A new family of symmetric (4-nitro-1H-pyrazole-3,5-diyl)bis(1H-1,2,4-Triazole)-based derivatives were obtained. All these new compounds were characterized by (1H, 13C)NMR spectroscopy, infrared spectroscopy, elemental analysis and differential scanning calorimetry (DSC). The structures of 5,5′-(4-nitro-1H-pyrazole-3,5-diyl)bis(3-nitro-1H-1,2,4-Triazole) (6) and N,N′-((4-nitro-1H-pyrazole-3,5-diyl)bis(1H-1,2,4-Triazole-5,3-diyl))dinitramide (7) were further confirmed by single crystal X-ray diffraction. In addition, the theoretical calculations by using the Gaussian 09 package show that target compounds have high heats of formation ranging from 1.40 to 2.84 kJ g-1. Among them, the safety and detonation performances of 6 (D: 8747 m s-1, P: 33.0 GPa, Td: 238.2 °C, IS: 30 J) and energetic salts dihydroxylammonium((4-nitro-1H-pyrazole-3,5-diyl)bis(1H-1,2,4-Triazole-5,3-diyl))bis(nitroamide) (9) (D: 9077 m s-1, P: 33.6 GPa, IS: >40 J) and dihydrazinium((4-nitro-1H-pyrazole-3,5-diyl)bis(1H-1,2,4-Triazole-5,3-diyl))bis(nitroamide) (10) (D: 8759 m s-1, P: 30.2 GPa, IS: >40 J) are comparable to those of 1,3,5-Trinitroperhydro-1,3,5-Triazine (RDX: D = 8795 m s-1, P = 34.9 GPa, Td = 210 °C, IS: 7.4 J) due to the positive effect of ternary hydrogen bonds.
- Xu, Minxian,Cheng, Guangbin,Xiong, Hualin,Wang, Bohan,Ju, Xuehai,Yang, Hongwei
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p. 11157 - 11163
(2019/07/19)
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- Four syntheses of 4-Amino-3,5-dinitropyrazole
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In this paper, syntheses of 4-amino-3,5-dinitropyrazole from four different starting materials are described. The starting materials were 4-nitropyrazole, 4-nitro-3,5-dimethylpyrazole, 3,5-dinitropyrazole, and 4-chloropyrazole, respectively. They are compared in terms of yield, number of steps and suitability for scale-up into pilot scale production. The overall yield, calculated from commercially available starting materials, ranged from 21% in the case of synthesis via 3,5-dinitropyrazole up to 61% for the one starting from 4-chloropyrazole. With numerous factors taken into account, the latter was chosen for a pilot scale study and the product could be produced in batches of 200 g.
- Ek, Stefan,Latypov, Nikolaj V.
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p. 1621 - 1627
(2015/01/09)
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- Pyrazolopyrimidine derivatives
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The present invention provides a compound of formula (I): where Q is a group of formula: These compounds inhibit cyclic guanosine 3',5'-monophosphate phosphodiesterases (cGMP PDEs). More notably, the compounds are potent and selective inhibitors of the type 5 cyclic guanosine 3',5'-monophosphate phosphodiesterases and have utility therefore in a variety of therapeutic areas. In particular, the present compounds are of value for the curative or prophylactic treatment of mammalian sexual disorders.
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- Synthesis and antitumor activity of a new class of pyrazolo[4,3- e]pyrrolo[1,2-a][1,4]diazepinone analogues of pyrrolo[1,4][2,1- c]benzodiazepines
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A new class of pyrrolo[1,4]benzodiazepine (PBD) analogues featuring a pyrazolo[4,3-e]pyrrolo[1,2-a][1,4]diazepinone ring system has been designed and synthesized. These compounds, 2a-o, are characterized by the substitution of the aromatic A ring, characteristic of the PBDs, with a disubstituted pyrazole ring bearing alkyl and benzyl substituents at N6 or N7 and alkyl or carbomethoxy substituents at C8. Biological evaluation revealed an appreciable in vitro cytotoxic activity for compounds 2a,b,f-i.
- Baraldi,Leoni,Cacciari,Manfredini,Simoni,Bergomi,Menta,Spinelli
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p. 4329 - 4337
(2007/10/02)
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