- Method for pipeline continuous fluorination with fluorine salt as fluorine source
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The method comprises the following steps: dissolving a fluorine salt in an aqueous polar aprotic solvent as reaction liquid A, dissolving an aryl (heterocyclic) chloride in a polar aprotic solvent as reaction liquid B, and reacting a polar aprotic solvent in the reaction liquid A with a polar aprotic solvent of the reaction liquid B. The reaction medium consisting of the preheated reaction liquid A and the preheated reaction liquid B enters the reaction coil for a fluorination reaction, and the resulting product from the reaction coil is subjected to post-treatment to obtain the product. The method has the characteristics of no need of adding a phase transfer catalyst, continuous production, low production cost and the like.
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Paragraph 0056-0061; 0094-0096
(2021/10/27)
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- Synthesis of fluorinated halonitrobenzenes and halonitrophenols using tetrafluoroethylene and buta-1,3-dienes as starting building blocks
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The gas-phase copyrolysis of tetrafluoroethylene with buta-1,3-diene in a flow reactor at 495–505 °C produces 3,3,4,4-tetrafluorocyclohex-1-ene, which selectively converted to 1,2-difluorobenzene or 1-chloro-2,3-difluorobenzene. The latter can be converted to 2-chloro-3,4-difluoronitrobenzene, 2,3,4-trifluoronitrobenzene, 2,3-difluoro-6-nitrophenol, or 2-chloro-3-fluoro-4-nitrophenol via nitration, fluorodechlorination, and hydrolysis reactions.
- Lipkind, M. B.,Nefedov, O. M.,Volchkov, N. V.
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p. 2156 - 2163
(2022/01/22)
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- Preparation method of 3, 4, 5-trifluorobromobenzene
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The invention relates to a preparation method of 3, 4, 5-trifluorobromobenzene, belongs to the technical field of chemical synthesis, and solves the problem that a byproduct 3, 4, 5-trichloronitrobenzene generated in a process of preparing 3, 4-dichloronitrobenzene by introducing chlorine into parachloronitrobenzene cannot be effectively utilized. The method comprises the step of preparing 3, 4, 5-trifluorobromobenzene by taking 3, 4, 5-trichloronitrobenzene as a raw material. According to the technical scheme provided by the invention, the utilization rate of raw materials and the efficiencyof the process can be improved, and high-value utilization of byproducts is realized.
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Paragraph 0100-0101; 0106; 0111
(2020/12/14)
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- Novel manufacturing method of fluoro-aryl compounds and derivatives thereof
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The invention relates to a novel method of manufacturing fluoro-aryl compounds and derivatives thereof, in particular, fluorobenzene and derivatives thereof. The production environment of the manufacturing method is environmentally friendly. The shortages of a conventional method are overcome through a simple and beneficial mode. Compared with the prior art, the provided method is more effective,more environmentally friendly, and more energy saving. The method is used to produce core fluorinated aromatic compounds, preferably, core fluorinated fluorobenzene. On one aspect, the invention provides a method, which is advantages in industry and uses HF and a halogenated benzene precursor to prepare fluorobenzene and hydrogen halide. Moreover, the invention provides chlorobenzene as the primary raw material to prepare fluorobenzene, which is an important material in industry, and a beneficial, unexpected and simple application of chlorobenzene. In the prior art, the provided application ofchlorobenzene is unknown.
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Paragraph 0201-0205; 0232-0236
(2020/01/25)
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- Preparation method of 2, 3, 4-trifluoronitrobenzene
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The invention belongs to the field of organic synthesis, and particularly relates to a preparation method of 2, 3, 4-trifluoronitrobenzene. The method comprises the following steps: reacting 2,6-dichlorofluorobenzene as a raw material with HNO3/H2SO4 so as to obtain 2, 6-dichloro-3-nitrofluorobenzene, and then reacting the 2, 6-dichloro-3-nitrofluorobenzene with anhydrous potassium fluoride to obtain the 2, 3, 4-trifluoronitrobenzene. The method disclosed by the invention is high in yield, simple in synthesis and suitable for industrial production.
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Paragraph 0012; 0014; 0015
(2019/05/15)
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- Preparation method of 2,3,4-trifluoronitrobenzene
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The invention discloses a preparation method of 2,3,4-trifluoronitrobenzene and relates to the field of organic synthesis. The preparation method specifically comprises the following steps: firstly, 2,3,4-trichloronitrobenzene is prepared from 1,2,3-trichlorobenzene as a raw material through nitrification and substitution; then KF is added, stirring is performed for dehydration under catalysis of TBAB, a reaction is performed at 180 DEG C, a product is filtered after the reaction, a filtrate is fed into a water-free reactor after being subjected to reduced-pressure distillation, KF is added, reduced-pressure dehydration is performed under catalysis of TBAF, a reaction is performed at 120 DEG C under the ultrasonic power condition of 30 KHZ, a reaction process is tracked by GC, a product is cooled to 70-75 DEG C and filtered after the reaction, a filtrate is distilled for separating DMSO and a product. The method is simple to operate, and the product yield is high.
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Paragraph 0028-0029; 0031-0034; 0036-0039; 0041-0044; 0046
(2018/01/03)
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- O-dichlorobenzene with a quinolone drugs for coproduction method of key intermediate
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The invention relates to the field of methods for preparing medicinal intermediates, in particular to the field of methods for preparing key intermediates of quinolone medicines, and develops a method for coproducing the key intermediates of the quinolone medicines by using o-dichlorobenzene as a raw material. The method comprises the following steps of: nitrifying the o-dichlorobenzene serving as the raw material, and performing distillation, purification and stepwise crystallization to obtain 2,3-dichloronitrobenzene and 3,4-dichloronitrobenzene; performing fluoridation on the 2,3-dichloronitrobenzene to obtain 3-chloro-2-fluoronitrobenzene, performing chlorination to obtain 2,6-dichlorofluorobenzene, performing nitration to obtain 1,3-dichloro-2-fluoro-4-nitrobenzene, and finally performing fluoridation to obtain 2,3,4-trifluoronitrobenzene; and performing fluoridation on the 2,3,4-trifluoronitrobenzene to obtain 3-chloro-4-fluoronitrobenzene, performing chlorination to obtain 1,3-dichloro-4-fluorobenzene, and finally performing acylation reaction on the 1,3-dichloro-4-fluorobenzene and acetylchloride to obtain 2,4-dichloro-5-fluoroacetophenone.
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- Process for preparing multiply fluorinated nitrobenzenes
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Multiply, preferably doubly or triply, fluorinated nitrobenzenes are prepared in an advantageous way from the corresponding chloronitrobenzenes and an alkali metal fluoride in a chlorine-fluorine exchange reaction by catalyzing the reaction with a quaternary ammonium compound comprising at least one alkoxypolyoxyalkyl radical.
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- Radical Anions of Aromatic Compounds. XXIV. Electrochemical Reduction of Polyhalogenated Nitrobenzene Derivatives
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Dependence of the peak potentials for reduction of complete series of fluorinated and chlorinated nitrobenzenes into radical anions on the number and position of halogen atoms has been studied by cyclic voltammetry.This dependence is described by linear relations involving standard ?p and ?m constants and also the constants that reflect the specific effect of a single ortho halogen atom and the nonadditivity of the effect of two ortho-located halogen atoms: ?o(F) 0.209, ?o,o(2F) 0.152, ?o(Cl) 0.15, and ?o,o(2Cl) 0.
- Selivanova, G. A.,Starichenko, V. F.,Shteingarts, V. D.
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p. 200 - 206
(2007/10/02)
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- POLYMER-SUPPORTED AMINOPYRIDINIUM SALTS AS VERSATILE CATALYSTS FOR THE SYNTHESIS OF ARYL FLUORIDES
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Immobilized N-alkylaminopyridinium salts on divinylbenzene crosslinked polystyrene gel was reusable at least 8 times on the reaction of 4-chloronitrobenzene with anhydrous potassium fluoride in tetrahydrothiophene 1,1-dioxide to give 4-fluoronitrobenzene in high yield.The immobilized catalyst was also successfully used for a synthesis of several aryl fluorides in good yields.
- Yoshida, Yasuo,Kimura, Yoshizaku,Tomoi, Masao
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p. 7199 - 7202
(2007/10/02)
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- Derivatives of pyrido-benzothiazine with high anti-microbial activity
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Pyrido-benzothiazine compounds having anti-microbial activity are prepared by (a) reacting 3-chloro-4-fluoroaniline with potassium thiocyanate and bromine to produce 2-amino-6-fluoro-7-chlorobenzothiazole, (b) reacting 2-amino-6-fluoro-7-chlorobenzothiazole with sodium hydroxide to produce the disulfide of 2-amino-5-fluoro 6-chlorothiophenol, (c) reacting the disulfide with sodium monochloroacetate to produce 7-fluoro-8-chloro-2H-1,4-benzothiazin-3(4H)-one, (d) reducing 7-fluoro-8-chloro-2H-1,4-benzothiazin-3(4H)-one to produce 7-fluoro-8-chloro-3,4-dihydro-2H-1,4-benzothiazone, (e) reacting 7-fluoro-8-chloro-3,4-dihydro-2-H-1,4-benzothiazone with ethyl ethoxymethylenemalonate and cyclyzing the intermediate formed with polyphosphoric acid to produce ethyl 9-fluoro-10-chloro-7-oxo-2,3-dihydro-7H-pyrido[1,2,3 de] [1,4]-benzothiazine-6-carboxylate and (f) hydrolyizing the ethyl carboxylate to produce the corresponding carboxylic acid.
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