- Catalyst and application thereof in synthesis of aromatic fluorine compounds
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The invention belongs to the field of catalyst preparation and application, and particularly relates to a catalyst and application thereof in synthesis of aromatic fluorine compounds. The nickel catalyst is dichloro-bis-(tri-cyclohexylphosphine) nickel, and the molecular formula of the nickel catalyst is Ni (Py3) 2Cl2. The nickel catalyst is applied to catalyzing inorganic fluoride to replace aromatic chloride to synthesize fluoride. The catalyst has the advantages of easily available reagents, simple catalyst synthesis, simple operation conditions, low reaction temperature, high reaction yield and less time consumption.
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Paragraph 0042-0044
(2020/11/10)
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- Preparation method of 3-chloro-4-fluoronitrobenzene
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The invention relates to a preparation method of 3-chloro-4-fluoronitrobenzene. The preparation method comprises the following steps that fluoronitrobenzene is used as a starting material and dilute acid serves as a reaction solvent in the process, reaction is performed with N-chlorinated succinimide at room temperature under the catalysis of a simple substance iodine according to a certain proportion, the 3-chloro-4-fluoronitrobenzene is prepared after 2-4 hours, a reaction system is diluted with a certain amount of water after reaction is completed, organic solvent extraction, water solution reduction, saturated salt water washing, anhydrous sodium sulfate drying and rotary evaporation and concentration are performed, and then a crude 3-chloro-4-fluoronitrobenzene product is obtained and is recrystallized to obtain a pure product. The reaction raw materials are easy to obtain, the price is reasonable, the reaction conditions are mild, operation and control are easy, posttreatment is simple, the product quality is stable, and the purity is high.
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Paragraph 0012; 0013; 0014; 0015; 0016; 0017; 0018
(2017/08/29)
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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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Paragraph 0020; 0066-0067
(2017/01/19)
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- Phosphonium ionic liquids as highly thermal stable and efficient phase transfer catalysts for solid-liquid Halex reactions
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Trihexyl (tetradecyl) phosphonium tetrafluoroborate was found to be an active catalyst for the introduction of fluoride by nucleophilic aromatic substitution. With a decomposition temperature above 300 °C, this ionic liquid is suitable for reactions at high temperatures. The addition of 1 mol% of the ionic liquid relative to KF increased the initial rate for the fluorination of 1,2-dichloro-4-nitrobenzene six-fold compared to the uncatalysed reaction. The highest reaction rate was observed at 20 mol% ionic liquid relative to KF. Ease of handling without the need for stringent drying conditions and reuseability make this ionic liquid a useful phase transfer catalyst.
- Fan, Ao,Chuah, Gaik-Khuan,Jaenicke, Stephan
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p. 300 - 304
(2013/01/15)
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- A PROCESS FOR SYNTHESIS OF 2, 4-DICHLORO-5- FLUOROACETOPHENONE (DCFA)
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A process for synthesis of 2,4-dichloro-5-fluoro acetophenone (DCFA) is disclosed. The process comprises first reacting 3,4-dichloronitrobenzene with potassium fluoride having bulk density in the range of 0.2 to 1.3, to form a fluorinated intermediate product, then reacting the intermediate product with chlorine to form dichlorofluorobenzene and finally acylating dichlorofluorobenzene using an acylating agent to form a mixture containing DCFA along with impurities, followed by purification and enrichment of DCFA in the mixture by melt crystallization.
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Page/Page column 15
(2010/07/10)
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- Novel lariat calix[4]-1,3-aza-crowns with two branched chains-the excellent phase transfer catalysts for nucleophilic substitution reaction
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By reacting calix[4]-1,3-diethoxylaminoethyl derivative (2) with phenyl isothiocyanate, novel dendritic calix[4]-arene derivative (3) with two different branched chains was synthesized in a yield of 78%. By reacting compound 2 with 1,6-diisocyanatohexane or N,N'-bis(2-chloracetamide)ethylene in a ''1 + 1'' intermolecular addition mode, novel lariat calix[4]-1,3-aza-crowns (4 and 5, respectively) with two branched ethoxyl chains were prepared in reasonable yields. The composition, structures, and conformations of all new compounds were confirmed by elemental analyses, IR, ESI-MS, 1H NMR, and so forth. The liquid-liquid extraction experiments showed that all new hosts possessed good extraction abilities towards soft and hard metal cations. The liquid membrane transport experiments suggested that they had good transport abilities for K+ and Ag+. The experiments of phase transfer catalysis indicated that they possessed excellent catalytic properties of aromatic nucleophilic substitution reaction and benzyl nucleophilic substitution. The optimum yields of products in catalytic reaction were as high as approximately 100%.
- Yang, Fafu,Wang, Yanhua,Guo, Hongyu,Xie, Jianwei,Liu, Zhiqiang
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experimental part
p. 622 - 627
(2010/08/22)
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- PROCESS FOR THE PRODUCTION OF FLUORINATED AROMATIC RINGS BY SIMULTANEOUS COOLING AND MICROWAVE HEATED HALOGEN EXCHANGE
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Shown is an improved method of adding fluorine atoms to aromatic rings, using microwave energy application and simultaneous cooling to enhance the fluorination process. The result is an energy efficient method of microwave-assisted halogen exchange (HALEX) reactions involving chloroaromatics and fluorinating agents, with the result being the addition of fluorine atoms into aromatic rings.
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Page/Page column 7
(2010/02/17)
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- Efficient phosphorus catalysts for the halogen-exchange (Halex) reaction
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New families of monomeric to dendritic, and monocationic to multicationic (PNP) compounds have been prepared and tested as catalysts in halogen exchange (Halex) reactions. Some of them allow an increase in the efficiency of these reactions which are performed in some cases under the mildest conditions reported up to now.
- Lacour, Marie-Agnes,Zablocka, Maria,Duhayon, Carine,Majoral, Jean-Pierre,Taillefer, Marc
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supporting information; experimental part
p. 2677 - 2682
(2009/10/20)
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- A polymer imidazole salt as phase-transfer catalyst in halex fluorination irradiated by microwave
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A new imidazole polymer salt was synthesized in order to develop a high efficiency phase-transfer catalyst for multi-phase reactions. The polymer salt was prepared easily by co-polymerization of 1-1′-(1,4-butamethylene)bis(imidazole) and 1,2-dibromoethane, and has the properties of excellent chemical and thermal stability and high ionic conductivity. It was applied as phase-transfer catalyst in the fluorination of chloronitrobenzenes under the irradiation of microwave and gave excellent yields of corresponding fluoronitrobenzenes. In addition, the enhanced mechanism of microwave was studied and found "non-thermal" effect was a great factor.
- Liang, Zheng Yong,Lü, Chun Xu,Luo, Jun,Dong, Li Bin
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p. 608 - 611
(2008/01/01)
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- A polymer onium acting as phase-transfer catalyst in halogen-exchange fluorination promoted by microwave
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A polymerized quaternary ammonium salt polydiallyldimethylammonium chloride, exhibiting high stability to heat and base, was prepared and applied as phase-transfer catalyst (PTC) in halogen-exchange (Halex) fluorination of chloronitrobenzenes to give excellent yields of corresponding fluoronitrobenzenes. Dimethyl sulfoxide was found to be the best solvent when microwave was applied as heating resource.
- Luo, Jun,Lü, Chunxu,Cai, Chun,Qü, Wenchao
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p. 701 - 704
(2007/10/03)
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- A novel method for the nitration of simple aromatic compounds
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Simple aromatic compounds such as benzene, alkylbenzenes, halogenobenzenes, and some disubstituted benzenes are nitrated in excellent yields with high regioselectivity under mild conditions using zeolite β as a catalyst and a stoichiometric quantity of nitric acid and acetic anhydride. The zeolite can be recycled, and the only byproduct is acetic acid, which can be separated easily from the nitration product by distillation; the process is inexpensive and represents an attractive method for the clean synthesis of a range of nitroaromatic compounds. For example, nitration of toluene gives a quantitative yield of mononitrotoluenes, of which 79% is 4-nitrotoluene; fluorobenzene gives a quantitative yield of mononitro compounds, of which 94% is 4-nitrofluorobenzene; and 2-fluorotoluene gives a 96% yield of mononitro products, of which 90% is the 5-nitro isomer and 10% is the 4-nitro isomer.
- Smith, Keith,Musson, Adam,DeBoos, Gareth A.
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p. 8448 - 8454
(2007/10/03)
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- Process for the preparation of aromatic fluorinated compounds and novel diamides
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Aromatic, ring-fluorinated compounds are prepared by reaction of corresponding chlorine compounds or bromine compounds with alkali metal fluorides using a diamide as solvent. Most of the diamides which can be used are novel compounds.
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- Tetramethylammonium chloride as a selective and robust phase transfer catalyst in a solid-liquid halex reaction: The role of water
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Tetramethylammonium chloride (TMAC) is an effective phase transfer catalyst for the selective chloride/fluoride exchange reaction of activated aryl chlorides with potassium fluoride provided that the amount of water in the system is limited and controlled.
- Sasson, Yoel,Negussie, Samuel,Royz, Michael,Mushkin, Noam
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p. 297 - 298
(2007/10/03)
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- Process for the preparation of chlorofluronitrobenzenes and difluoronitrobenzenes
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A process for the preparation of chlorofluoronitrobenzenes and difluoronitrobenzenes, which comprises heating dichloronitrobenzene to not more than 200° C. in excess with an alkali metal fluoride having a total water content of about 0.2 to about 2.5% by weight in the presence of a quaternary ammonium and/or phosphonium salt, crown ether and/or polyethylene glycol dimethyl ether as catalyst in the absence of a solvent.
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- Process for preparing fluoronitrobenzenes
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Fluoronitrobenzenes are prepared in an advantageous way from the corresponding chloronitrobenzenes and an alkali metal fluoride by means of a chlorine-fluorine exchange reaction with replacement of a chlorine atom by a fluorine atom, by catalyzing the reaction with a quaternaryammonium compound which comprises at least one alkoxypolyoxyalkyl radical.
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- PHASE-TRANSFER CATALYSIS IN THE FLUORODECHLORINATION OF CHLORONITROARENES
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The activity of phase-transfer catalysts during the fluorodechlorination of chloronitroarenes in the absence of aprotic polar solvents was compared.The optimum conditions for the process were selected.
- Deev, L. E.,Nazarenko, T. I.,Podsevalov, P. V.
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p. 1925 - 1929
(2007/10/03)
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- Selective fluorodenitration of chloronitroaromatics
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Nucleophilic fluorination of chloronitrobenzenes shows a strong bias for fluorodenitration rather than halogen exchange.
- Beaumont, Andrew J.,Clark, James H.,Boechat, Nubia A.
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- Process for producing chlorofluorobenzenes
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A process for producing chlorofluorobenzenes, which comprises reacting fluorine-containing nitrobenzenes of the following formula (1) with chlorine gas to obtain chlorofluorobenzenes of the following formula (2): STR1 wherein n and m are integers satisfying 1≤n≤3, 0≤m≤2 and 1≤n+m≤3.
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- A convenient and new modified preparation of nitrosubstituted aryl fluorides
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Nitrosubstituted aryl fluorides are easily prepared in good yields from chloro-nitrobenzenes and potassium fluoride in dimethyl sulfoxide and in the presence of polyethylene glycol 5090.
- Deutsch,Niclas
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p. 505 - 513
(2007/10/02)
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- Tetraphenylphosphonium Salts-Grafted Copolymers as Catalysts for Halogen-Exchange Fluorinations
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Cross-linked styrene/2-(4-chlorophenyl)propene copolymer-grafted tetraphenylphosphonium salt was an effective and reusable catalyst for the reaction of aromatic chlorides with anhydrous potassium fluoride to afford the corresponding aromatic fluorides in good yields.
- Yoshida, Yasuo,Kimura, Yoshikazu,Tomoi, Masao
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p. 769 - 772
(2007/10/02)
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- Process for introducing fluorine atoms into aromatic rings by nucleophilic exchange
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Aromatic, ring-fluorinated compounds are particularly advantageously prepared by nucleophilic exchange in the course of reaction wih potassium fluoride in the presence of phase transfer catalysts and, if desired, solvents by carrying out the reaction in the additional presence of metal salts.
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- Hydroxylamine derivative of 5-nitro-8-hydroxy quinoline
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Novel hydroxylamino derivatives of the formula wherein Ar is selected from the group consisting of mono- and polycyclic aromatics and hetero-aromatics, both optionally substituted with at least one member of the group consisting of --OH, halogen, --NO2, --CN, STR1 --R7, --OR8, STR2 --SO2 R12, --SO3 R13, --COOR14, aryl of 6 to 14 carbon atoms, --OR16, --CH2 --CN and --CH2 SO2 --R15, R1, R2, R3, R4, R5 and R6 are individually selected from the group consisting of hydrogen and alkyl of 1 to 8 carbon atoms, R7 and R8 are optionally unsaturated alkyl of 1 to 8 carbon atoms optionally substituted with at least one member of the group consisting of halogen and cyano, R9, R10, R11, R12 and R13 are alkyl of 1 to 8 carbon atoms, Z is selected from the group consisting of hydrogen, optionally unsaturated alkyl of 1 to 8 carbon atoms and acyl of an organic carboxylic acid of 2 to 18 carbon atoms, R14 is selected from the group consisting of hydrogen and alkyl of 1 to 8 carbon atoms, R15 is selected from the group consisting of alkyl of 1 to 8 carbon atoms and aryl of 6 to 14 carbon atoms optionally substituted with an alkyl of 1 to 8 carbon atoms, R16 is aryl of 6 to 14 carbon atoms optionally substituted with a member of the group consisting of alkyl of 1 to 8 carbon atoms, halogen and --NO2, the substituents of Ar being able to form rings containing at least one heteroatom selected from the group consisting of oxygen, nitrogen and sulfur and their non-toxic agriculturally acceptable acid addition salts with the proviso Ar is not phenyl nor phenyl with one methyl in the 2,3 or 4 position, a nitro in the 2- or 4-position, a chlorine in the 3- or 4-position, a bromine in the 4-position or a --CF3 in the 4-position nor 2,4-dinitrophenyl nor 2-nitro-4-trifluoromethylphenyl nor 2,6-dinitrophenyl nor 2,4,6-trinitrophenyl nor 2,4-dinitro-6-trifluoromethylphenyl useful for increasing vegetation growth and increasing crop yields and their preparation.
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- Preparation of substituted fluorobenzenes
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A process for the preparation of substituted fluorobenzenes which contain a nitro group or a cyano group and may or may not contain an aliphatic radical or an additional halogen atom, wherein the corresponding substituted chlorobenzene is reacted with potassium fluoride in the presence of a crown ether and a solvent at from 150° to 230° C.
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- Manufacture of substituted fluorobenzenes
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Fluorobenzenes are manufactured by reacting substituted chlorobenzenes with potassium fluoride in the presence of catalytic amounts of cesium fluoride and in the presence of certain solvents; m-nitrofluorobenzenes and m-cyanofluorobenzenes can also be manufactured in the absence of cesium fluoride. The products are starting materials for the manufacture of dyes, pharmaceuticals and pesticides.
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- Preparation of fluoronitrobenzene
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A method of preparing a fluoronitrobenzene containing a fluorine atom in the para position with respect to the nitro group, comprising heating a polychloronitrobenzene or chloronitrobenzene containing a chlorine atom in the para position with respect to the nitro group with an alkali metal fluoride in the presence of sulpholane.
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