- Inexpensive, Active KF for Nucleophilic Aromatic Displacement Reactions
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The simple, and inexpensive process, of recrystallizing KF from a methanol solution by slow evaporation of the solvent, followed by drying at 100 deg C, results in a highly active form of KF.The surface area was increased 20 fold by this process.This pre-treated KF proved to be considerably more efficient as a source of fluoride ion than untreated KF in the conversion of 2,4-dichloronitrobenzene to 2,4-difluoronitrobenzene.It was observed to be more efficient than spray dried KF but was less efficient than KF supported on CaF2.The results of a kinetic analysis of the above reaction using the pre-treated KF point towards a solid-liquid interfacial mechanism.
- Smyth, Timothy P.,Carey, Aedin,Hodnett, B. K.
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Read Online
- Novel preparation method of 2, 4, 5-trifluorophenylacetic acid
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The invention discloses a novel preparation method of 2, 4, 5-trifluorophenylacetic acid, which belongs to the technical field of preparation of medical intermediates, and comprises the following preparation steps: carrying out nitration reaction on sulfuric acid and m-dichlorobenzene to obtain an intermediate II; adding the intermediate II, a phase transfer catalyst and potassium fluoride into an aprotic solvent to obtain an intermediate III; performing hydrogenation reaction on the intermediate III to obtain an intermediate IV; carrying out diazotization reaction on the intermediate IV, nitrosyl sulfuric acid and sodium fluoborate to obtain an intermediate V; performing cracking reaction on the intermediate V to obtain an intermediate VI; carrying out reduction reaction on the intermediate VI, and then carrying out bromination reaction on the intermediate VI and liquid bromine to obtain an intermediate VII; subjecting the intermediate VII to a substitution reaction with diethyl malonate, and obtaining 2, 4, 5-trifluorophenylacetic acid after hydrolysis and purification. A novel synthesis route is provided, the problem that technological operation is tedious is solved, the requirements for reaction and operation conditions are low, anhydrous and oxygen-free reaction conditions are not needed, the method is suitable for industrial production, and the yield and purity are greatly improved.
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Paragraph 0037; 0075; 0078-0079; 0097-0100; 0102-0103; ...
(2021/06/23)
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- Preparation method of fluorine-containing aryl compound
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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.
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Paragraph 0126-0134
(2021/06/12)
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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; 0219-0224
(2020/01/25)
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- 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 0039-0041
(2020/11/10)
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- Efficient synthesis method of meta-fluoranisole (by machine translation)
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The method is characterized by comprising the following steps: taking m-chloronitrobenzene as a raw material, carrying out high-temperature chlorination reaction, nitration reaction and fluorination reaction to obtain 2,4 - 2,4 -difluorobenzene and carrying out a methoxylation reaction with m-difluorobenzene as a raw material and carrying out methoxylation reaction to obtain m-fluorobenzyl ether; and the hydrogenation catalyst is a porous alumina loaded NiO-Co222O3-MoOO3 composite catalyst. The method disclosed by the invention is simple in process and high in product yield. (by machine translation)
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Paragraph 0026; 0032; 0036; 0042; 0046; 0052; 0056; 0062
(2020/06/05)
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- N-Nitroheterocycles: Bench-Stable Organic Reagents for Catalytic Ipso-Nitration of Aryl- And Heteroarylboronic Acids
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Photocatalytic and metal-free protocols to access various aromatic and heteroaromatic nitro compounds through ipso-nitration of readily available boronic acid derivatives were developed using non-metal-based, bench-stable, and recyclable nitrating reagents. These methods are operationally simple, mild, regioselective, and possess excellent functional group compatibility, delivering desired products in up to 99% yield.
- Budinská, Alena,Katayev, Dmitry,Passera, Alessandro,Zhang, Kun
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supporting information
(2020/03/30)
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- A convenient room temperature ipso-nitration of arylboronic acid catalysed by molecular iodine using zirconium oxynitrate as nitrating species: An experimental and theoretical investigation
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A simple and convenient protocol has been developed for ipso-nitration of arylboronic acid catalysed by molecular iodine at room temperature, using zirconium oxynitrate as the nitrating species. The protocol is applicable to electronically diverse aryl- and heteroarylboronic acid moieties under mild reaction conditions with good to excellent isolated yields. Furthermore, a theoretical investigation has been performed for the same reaction, and reaction profiles are modelled using modern density functional theory (DFT). DFT-based results support the experimentally observed results.
- Mahanta, Abhijit,Gour, Nanda Kishor,Sarma, Plaban Jyoti,Borah, Raju Kumar,Raul, Prasanta Kumar,Deka, Ramesh Chandra,Thakur, Ashim Jyoti,Bora, Utpal
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- Click chemistry inspired facile synthesis and bioevaluation of novel triazolyl analogs of Ludartin
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A convenient and modular synthesis involving diastereoselective Michael addition followed by regioselective Huisgen 1,3-dipolar cycloaddition reaction was carried out to furnish 1,4-disubstituted-1,2,3-triazoles of Ludartin. This reaction scheme involving Michael addition followed by regioselective Huisgen 1,3-dipolar cycloaddition reaction leading to the formation of triazolyl analogs is being reported for the first time. All the triazolyl products were characterised using spectral data analysis. Sulphorhodamine B cytotoxicity screening of the resulting products against a panel of five human cancerous cell-lines revealed that few of the analogs display promising broad spectrum cytotoxic effect. Among all the synthesized compounds, only 3q displayed the best cytotoxic effect with IC50 values of 12, 11, 38, 39 and 8.5 μM but less than the standard Ludartin (1) with IC50 values of 6.3, 7.4, 7.5, 6.9 and 0.5 μM against human neuroblastoma (T98G), lung (A-549), prostate (PC-3), colon (HCT-116) and breast (MCF-7) cancer cell lines, respectively. The present synthesis was designed based on the previous literature reports of Ludartin as an aromatase inhibitor. Our work provides an initial study on structure-activity relationship of triazolyl analogs of sesquiterpene lactones in general and Ludartin (1) in particular.
- Lone, Shabir H.,Bhat, Khursheed A.,Majeed, Rabiya,Hamid, Abid,Khuroo, Mohd A.
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p. 1047 - 1051
(2014/03/21)
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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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- Sequential continuous flow processes for the oxidation of amines and azides by using HOF·MeCN
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The generation and use of the highly potent oxidising agent HOF·MeCN in a controlled single continuous flow process is described. Oxidations of amines and azides to corresponding nitrated systems by using fluorine gas, water and acetonitrile by sequential gas-liquid/liquid-liquid continuous flow procedures are reported. Oxidation in flow: The oxidation of amines and azides to the corresponding nitrated systems by using fluorine gas, water and acetonitrile by sequential gas-liquid/liquid-liquid continuous flow procedures are reported. Copyright
- McPake, Christopher B.,Murray, Christopher B.,Sandford, Graham
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experimental part
p. 312 - 319
(2012/06/15)
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- POTASSIUM FLUORIDE DISPERSION SOLUTION, AND PROCESS FOR PRODUCTION OF FLUORINATED ORGANIC COMPOUND USING THE SAME
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A potassium fluoride dispersion essentially consisting of potassium fluoride and an aprotic organic solvent having a boiling point higher than that of methanol, which is obtainable by mixing a mixture containing potassium fluoride and 5 to 50 parts by weight of methanol per 1 part by weight of potassium fluoride with the aprotic organic solvent followed by concentrating the obtained mixture, and a process for producing a fluorine-containing organic compound comprising contacting an organic compound having at least one group capable of being substituted nucleophilically with a fluorine atom with the potassium fluoride dispersion.
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Page/Page column 8
(2009/04/25)
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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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- Use of nitriles as polar aprotic solvents
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The invention concerns the use of aliphatic nitriles with relatively high molecular weight, as polar aprotic solvents, in particular in nucleophilic substitution reactions of the aromatic type. Said nitriles have a molecular mass more 79, preferably more than 90. The invention is useful for synthesis of fluorinated aromatic compounds.
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- Process for preparing fluorine-containing compounds
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The present invention relates to a process for preparing fluorine-containing compounds by reacting a compound which contains fluorine-exchangeable halogen with a fluoride or a mixture of fluorides with the formula IMeF??(I),in which Me is an alkaline earth metal ion, NH4+-ion or alkali metal ion, in the presence of a compound or a mixture of compounds of the formula (II) in which A1, A2, A3, A4, A5, A6, A7, A8 independently of one another are identical or different and are a straight-chain or branched alkyl or alkenyl having 1 to 12 carbon atoms, cycloalkyl having 4 to 8 carbon atoms, an aryl having 6 to 12 carbon atoms, or an aralkyl having 7 to 12 carbon atoms, or A1 A2, A3A4, A5A6, and A7A8 independently of one another are identical or different and are connected to one another directly or by way of O or N—A9 to form a ring having 3 to 7 ring members, A9 is an alkyl having 1 to 4 carbon atoms and B?is a monovalent acid radical or the equivalent of a polyvalent acid radical, in the presence or absence of a solvent at a temperature from 40 to 260° C.
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- Electrophilic ipso substitution of trimethylsilyl groups in fluorobenzenes
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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.
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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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- 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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- 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 synthesis of fluorinated derivatives
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A process for the synthesis of fluorinated organic compounds and a reagent suitable for use in the process. The process is carried out by exchange with fluorides, while preferably agitating the reaction medium with ultrasonic sound.
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- Process for the hydrogenation of halogenonitro-aromatic compounds in the presence of a sulfur-containing compound
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A process for the hydrogenation of halogenonitro-aromatic compounds wherein said compounds are contacted with a nickel-, cobalt- or iron-based catalyst, preferably Raney nickel, and hydrogen in the presence of a sulfur-containing compound. Preferably, the sulfur-containing compound is a sulfoxide or sulfone, and the molar ratio of the sulfur-containing compound to the catalyst ranges from about 1:1 to 10:1.
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- Preparation of fluoroaromatic compounds in dispersion of potassium fluoride
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An improved process is disclosed for preparing fluoroaromatic compounds (such as fluoronitrobenzene compounds) wherein chloroaromatic compounds (such as chloronitrobenzene compounds) are reacted with potassium fluoride in a solvent dispersion thereof prepared from a mixture including the solvent, the fluoride, methanol and an aromatic compound.
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- SUBSTITUTION AND ADDITION REACTIONS OF NF4BF4 WITH AROMATIC COMPOUNDS
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Benzene, toluene, and nitrobenzene interact rapidly with NF4BF4 in anhydrous HF to give, almost exclusively, fluorine substituted aromatic derivatives.Up to four hydrogens can be replaced in a rapid reaction, before a much slower addition reaction takes over.The direction of the substitution in C6H6, C6H5CH3 and C6H5NO2 and the lack of side chain fluorination in C6H5CH3 support an electrophilic substitution mechanism.These rapid substitution reactions are followed by much slower fluorine addition reactions to give the corresponding cyclo-hexadienes and -hexenes.These addition reactions were also studied separately using tetra-, penta-, and hexa- fluorobenzene as the starting materials.In these addition reactions, almost no hydrogen substitution occurred.The addition of the first pair of fluorines always gave 1,4-cyclohexadienes in which the CF2 group was adjacent to hydrogen on the ring.The addition of the second pair of fluorines resulted in the formation of cyclohexenes.These reactions occured in high yield and offer a controlled, high yield path to dienes.All products were characterized spectroscopically and by comparison to literature data.
- Schack, Carl J.,Christe, Karl O.
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p. 363 - 374
(2007/10/02)
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- Thieno[3,2-b]-[1,5]benzodiazepines
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Thieno[1,5]benzodiazepines having useful CNS activity containing the novel tricyclic ring system: STR1 the 10-position being substituted by an amino, preferably a piperazino, group.
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