- Preparation method of fluorine-containing aryl compound
-
The invention relates to the field of organic synthesis, and especially relates to a preparation method of a fluorine-containing aryl compound. The invention provides a preparation method of a compound as shown in a formula 1. The preparation method comprises the following steps: fluorination reaction: reacting a compound as shown in a formula 2 with alkali metal fluoride in the presence of a phase transfer catalyst to prepare the compound as shown in the formula 1. According to the preparation method of the fluorine-containing aryl compound provided by the invention, a reaction system does not contain a solvent, the boiling point of the phase transfer catalyst is relatively high, solvent interference is avoided during rectification or short steaming after the reaction is finished, the distillation yield is high, and the product purity is good.
- -
-
Paragraph 0192-0199
(2021/06/12)
-
- Synthesis and Characterization of Fluorodinitrobenzenes with Tunable Melting Point: Potential Low Sensitive Energetic Plasticizer and Melt-Cast Carrier?
-
In order to explore the effects of fluoro substituents on the energy and safety of energetic compounds, a series of fluorodinitrobenzenes including 1,3-difluoro-2,4-dinitrobenzene (1), 1,5-difluoro-2,4-dinitrobenzene (2), 1,2,3-trifluoro-4,6-dinitrobenzne (3) and 1,3,5-trifluoro-2,4-dinitrobenzene (4) were prepared. All the compounds were fully characterized. The structures of 2 and 3 were further confirmed by single crystal X-ray diffraction analysis. The results show that these compounds exhibit comparable detonation properties (D = 6703-6978 m·s–1, and p = 21.3—23.7 GPa) to those of 2,4,6-trinitrotoluene (TNT) due to the significantly increased density of fluorine introduced. Low sensitivity (IS > 40 J, and FS > 360 N) of these compounds along with different melting points make them potential candidates for different allocation. Among them, 1 and 4 with the melting point of 42.5 °C and 55.2 °C, respectively, show promise for application in the field of energetic plasticizer. Compounds 2 and 3 are potential low sensitive melt-cast carrier due to their similar melting point and superior detonation performance to that of TNT.
- Li, Yunlu,Chen, Peng,Liu, Yan,Yin, Ping,He, Chunlin,Pang, Siping
-
p. 1619 - 1624
(2020/10/12)
-
- Method of preparing 1,5-difluoro-2,4-dinitrobenzene
-
The invention discloses a method of preparing 1,5-difluoro-2,4-dinitrobenzene. According to the method, 1,5-difluoro-2,4-dinitrobenzene is prepared via nitration in a concentrated sulfuric acid and fuming nitric acid mixed system by taking m-difluorobenzene as a starting raw material. A synthesis process is very simple and convenient; reaction conditions are mild; the raw material is cheap and easy to obtain; fewer byproducts are generated in a preparation process; the productivity is higher; a product with higher purity can be obtained without recrystallization operation; and industrial production can be performed.
- -
-
Paragraph 0027-0054
(2017/07/21)
-
- Synthesis and Detonation Properties of 5-Amino-2,4,6-trinitro-1,3-dihydroxy-benzene
-
5-Amino-4,6-dinitro-1,3-dihydroxy-benzene (6) was synthesized through the ring-opening reaction of macrocyclic compound 4 with the aid of VNS (vicarious nucleophilic substitution of hydrogen) reaction conditions. The mechanism of ring opening of macrocyclic compound 4 was studied. 5-Amino-2,4,6-trinitro-1,3-dihydroxy-benzene (8) was obtained after the nitration of 6 in KNO3 and concentrated sulfuric acid. The thermal stability, sensitivity, and other detonation performances of 6 or 8 were compared to commercially used 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) or 1,3,5-trinitrotriazacyclohexane (RDX), respectively. All target compounds were characterized by using single-crystal X-ray diffraction, NMR spectroscopy, elemental analysis, and differential scanning calorimetry. The sensitivities were determined by using BAM methods (drop-hammer and friction tests). Performance parameters, including heats of formation and detonation properties, were calculated by using Gaussian 03 and EXPLO5 v6.01 programs, respectively. It is worth pointing out that compound 8 has a remarkable measured density of 2.078 g cm?3 at 298 K. In addition, compound 8 is more insensitive than RDX (compound 8: IS=11 J; RDX: IS=7 J; IS is the impact sensitivity).
- Zhang, Xingcheng,Xiong, Hualin,Yang, Hongwei,Cheng, Guangbin
-
p. 447 - 451
(2017/06/23)
-
- Production method of flumioxazin
-
The invention discloses a production method of flumioxazin. The production method comprises the following steps: by using 2,4-difluoronitrobenzene as an initial raw material, sequentially carrying out nitrification to obtain 1,5-difluoro-2,4-dinitrobenzene, and carrying out etherification reaction on the 1,5-difluoro-2,4-dinitrobenzene and butyl hydroxyacetate to obtain butyl 3-fluoro-4,6-dinitrophenoxyacetate; carrying out reduction cyclization with hydrogen to obtain 7-fluoro-6-amino-2H-1,4-benzoxazinyl-3(4H)-one; under alkaline conditions, carrying out alkynylation reaction with propargyl chloride to obtain an intermediate product; and finally, carrying out amidation reaction with 3,4,5,6-tetrahydrophthalic anhydride to obtain the flumioxazin. The production technique of the method has the advantages of short process, mild reaction conditions and cheap and accessible raw materials, and is convenient to operate; and the solvent used in the preparation process is recyclable. The method also has the advantages of high total reaction yield, high product purity, low production cost and low environmental pollution.
- -
-
Paragraph 0041; 0045; 0046
(2017/01/26)
-
- One-pot formation of aromatic tetraurea macrocycles
-
Treating derivatives of m-phenylenediamine having different electron-richness and reactivities with triphosgene in the presence of triethylamine led to aromatic tetraurea macrocycles in high yields. Factors important for efficiently forming these macrocycles include the molar ratio (2:1) between the diamine and triphosgene, reaction temperature (-75 °C), and solvent (CH2Cl2). By controlling the order and rate for adding diamines, tetraurea macrocycles consisting of two different types of monomeric residues have also been obtained in high yields.
- Wu, Zehui,Hu, Ting,He, Lan,Gong, Bing
-
supporting information; experimental part
p. 2504 - 2507
(2012/07/13)
-
- Electrophilic ipso substitution of trimethylsilyl groups in fluorobenzenes
-
Using variants of literature methods 2,4- and 2,6- difluorophenyltrimethylsilanes have been bromodesilylated to the corresponding bromodifluorobenzenes in moderate to good yields, 3-bromo-2,6-difluorophenyltrimethylsilane afforded 1,3-dibromo-2,4-difluorobenzene whilst 1,3-difluoro-2,4-bis(trimethylsilyl)benzene yielded 3-bromo-2,6-difluorophenyltrimethylsilane. Application of either the Eaborn or Chvalovsky methods of nitrodesilylation to 4-fluorophenyltrimethylsilane, 2,4-difluorophenyltrimethylsilane and 2,6-difluorophenyltrimethylsilane afforded largely the corresponding desilylated products together with products associated with initial protodesilylation, followed by nitration of the resulting fluorobenzenes. The results obtained show that ipso desilylation in the fluoroaromatic series does follow the expected pattern previously obtained in the hydrocarbon analogues. They also show that in some cases the formation of unusually substituted fluoroarenes can be achieved more readily than by the methods previously used.
- Coe, Paul L.,Stuart, Alison M.,Moody, David J.
-
-