- Synthesis of Halogenated Esters of Fluorinated Carboxylic Acids by the Regio- and Stereospecific Addition of Acyl Hypochlorites to Olefins
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Addition reactions of the fluorinated acyl hypochlorites CF3CO2Cl, C2F5CO2Cl, n-C3F7CO2Cl, ClCF2CO2Cl, and HCF2CO2Cl with CF2=CF2 and CF2=CH2 form the respective esters in varying yields.The reactions are regiospecific with CF2=CH2.Additional reactions of CF3CO2Cl with CF2=CFCl, CF2=CCl2, CH2=CH2, and cis- and trans-CFH=CFH further illustrate the potential of the acyl hypochlorites for the synthesis of a variety of esters.In addition, the latter reactions provide further examples of the regiospecificity of these additions and two examples of their stereospecificity.A concerted cis addition is proposed.The new esters exhibit excellent thermal stability, but are unstable in the presence of KF.
- Tari, Isao,DesMarteau, Darryl D.
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Read Online
- Decarbonylative Fluoroalkylation at Palladium(II): From Fundamental Organometallic Studies to Catalysis
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This Article describes the development of a decarbonylative Pd-catalyzed aryl-fluoroalkyl bond-forming reaction that couples fluoroalkylcarboxylic acid-derived electrophiles [RFC(O)X] with aryl organometallics (Ar-M′). This reaction was optimized by interrogating the individual steps of the catalytic cycle (oxidative addition, carbonyl de-insertion, transmetalation, and reductive elimination) to identify a compatible pair of coupling partners and an appropriate Pd catalyst. These stoichiometric organometallic studies revealed several critical elements for reaction design. First, uncatalyzed background reactions between RFC(O)X and Ar-M′ can be avoided by using M′ = boronate ester. Second, carbonyl de-insertion and Ar-RF reductive elimination are the two slowest steps of the catalytic cycle when RF = CF3. Both steps are dramatically accelerated upon changing to RF = CHF2. Computational studies reveal that a favorable F2C-H - -X interaction contributes to accelerating carbonyl de-insertion in this system. Finally, transmetalation is slow with X = difluoroacetate but fast with X = F. Ultimately, these studies enabled the development of an (SPhos)Pd-catalyzed decarbonylative difluoromethylation of aryl neopentylglycol boronate esters with difluoroacetyl fluoride.
- Lalloo, Naish,Malapit, Christian A.,Taimoory, S. Maryamdokht,Brigham, Conor E.,Sanford, Melanie S.
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supporting information
p. 18617 - 18625
(2021/11/16)
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- Synthetic method of ethyl 4, 4-difluoro-3-oxo-2-piperidine-1-yl methylene butyrate
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The invention relates to a synthetic method of ethyl 4, 4-difluoro-3-oxo-2-piperidine-1-methylene butyrate. The synthetic method comprises the following steps: 1, carrying out a condensation reactionon difluoroacetyl fluoride and 3-(1-piperidyl)-ethyl acrylate to generate 4, 4-difluoro-3-oxo-2-piperidine-1-yl methylene ethyl butyrate and hydrogen fluoride, and 2, carrying out a reaction on the hydrogen fluoride generated in the step 1 and trichloroethylene under the action of a fluorination catalyst to generate trifluoroethylene and hydrogen chloride, and 3, reacting the trifluoroethylene generated in the step 2 with oxygen under the action of a complex catalyst to generate difluoroacetyl fluoride, and recycling the difluoroacetyl fluoride generated in the step 3 as a reactant in the step1. According to the synthetic method of the ethyl 4, 4-difluoro-3oxo-2-piperidine-1-methylene butyrate, the raw materials are simple and easy to obtain, the atom utilization rate is high, and the production safety is high.
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Paragraph 0025; 0029; 0035; 0040; 0043; 0048; 0051; 0056
(2021/01/30)
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- Synthetic method of difluoroacetyl fluoride
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The invention relates to a synthesis method of difluoroacetyl fluoride, which comprises the following steps: 1. reacting trichloroethylene with oxygen under the catalytic action of trialkyl boron shown in the formula I to generate dichloroacetyl chloride, and 2. reacting dichloroacetyl chloride with inorganic fluoride shown in the formula II under the action of a catalyst to generate difluoroacetyl fluoride. According to the synthetic method of difluoroacetyl fluoride, the raw materials are simple and easy to obtain, high-temperature reaction is not needed, and the yield is high.
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Paragraph 0041; 0045-0046; 0058; 0062-0063; 0066; 0070-0071
(2020/12/10)
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- METHOD FOR THE PREPARATION OF 3-FLUOROALKYL-1-METHYLPYRAZOL-4-CARBOXYLIC ACID
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The present invention relates to method for the preparation of 3-fluoroalkyl-1-methylpyrazol-4-carboxylic acid, wherein it comprises the following steps: step 1, fluoroacetyl fluoride derivative shown in Formula I undergoes condensation with dimethylamino vinyl methyl ketone, as a result, 3-dimethylamino methylene-fluoro-2,4-pentanedione derivative shown in Formula II is formed; step 2, ring closing reaction takes place between said 3-dimethylamino methylene-fluoro-2,4-pentanedione shown in Formula II and methylhydrazine, in this way, 3-fluoroalkyl-1-methyl-4-acetyl pyrazol derivative shown in Formula III is obtained; step 3, the said 3-fluoroalkyl-1-methyl-4-acetyl pyrazol derivative shown in Formula III is oxidized in the presence of alkali, and then acidified, in this way, 3-fluoroalkyl-1-methylpyrazol-4-carboxylic acid shown in Formula IV is formed. Preparing method of present invention, wherein the required preparing route is simple, the raw material cost is low, the resulting yield of each step is high, and it is suitable for industrialization.
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Paragraph 0032
(2018/10/19)
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- Preparation method of 2,2-difluoroacetyl fluoride and derivative thereof
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The invention belongs to the field of fluorine chemical industry and particularly relates to a preparation method of 2,2-difluoroacetyl fluoride and a derivative thereof. The preparation method takes 1,1,2,2-tetrafluoroethyl ethyl ether as a raw material, and the raw material reacts under the action of a catalyst to prepare the product. The catalyst is prepared by adopting a method comprising the following steps: taking rare-earth metal oxide as a raw material and activating at high temperature; and introducing CHF2Cl and reacting. The preparation method takes the 1,1,2,2-tetrafluoroethyl ethyl ether as the raw material, and the 1,1,2,2-tetrafluoroethyl ethyl ether has oxidization reaction under the action of the catalyst at 140 DEG C to 160 DEG C to generate acyl fluoride; and the preparation method has simple and safe production steps and short reaction time.
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Paragraph 0029-0046
(2017/07/21)
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- New process for preparing pyrazole carboxylic acid derivatives
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The present invention relates to a method for preparing a pyrazole carboxylic acid derivative. More particularly, the present invention relates to a novel method for preparing 1-alkyl-3-haloalkyl pyrazole-4-carboxylic acid represented by chemical formula (I) and useful for an intermediate for the preparation of a pyrazole carboxanilide-based sterilizing agent. In chemical formula (I), R_1 represents a C1-C3 lower alkyl group, R_2 represents any one of CHF_2, CF_3, CHCl_2 and CCl_2.COPYRIGHT KIPO 2017
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Paragraph 0051; 0077; 0078
(2017/04/03)
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- A process for preparing pirazole carbaldehyde compounds
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The present invention relates to a method for preparing pirazole carbaldehyde compounds and, more specifically, to a novel method for preparing 3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carbaldehyde and 3-(trifluoromethyl)-1-methyl-1-H-pyrazole-4-carbaldehyde which are useful as intermediates for producing pyrazole carboxanilide disinfectants such as isopyrazam, sedaxane, bixafen, etc. According to the present invention, production costs of pyrazole carboxanilide disinfectants can be reduced.COPYRIGHT KIPO 2017
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Paragraph 0079-0081
(2018/02/24)
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- Synthesizing method for ethyl difluoroacetate
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The invention relates to a synthesizing method, in particular to a synthesizing method for ethyl difluoroacetate, and aims at solving the problems that an existing synthesizing method for the ethyl difluoroacetate is complex in technological process, low in safety and high in preparation cost. The synthesizing method comprises the steps that 1, a catalyst is prepared, wherein a tubular reactor is filled with Al2O3 powder with the certain particle size meshes, it is guaranteed that the height of the Al2O3 powder is in a heating area of the tubular furnace, the temperature is increased to 250 DEG C-300 DEG C under nitrogen protection and kept for 12 h, CHaFbClc gas is continuously and slowly introduced for a reaction, the reaction temperature is set at 250 DEG C-300 DEG C, and the reaction time is set for 12 h; 2, 1,1,2,2-tetrafluoroethyl ethylether is taken as raw materials for a reaction under the conditions of the certain temperature and the catalyst, and an intermediate does not need to be separated and is directly collected through condenser to be converted into ethyl ester. The method belongs to the field of chemical engineering.
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Paragraph 0032-0042
(2017/03/24)
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- Method for Producing Difluoroacetyl Chloride
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A production method of difluoroacetyl chloride according to the present invention includes a chlorination step of bringing a raw material containing at least either a 1-alkoxy-1,1,2,2-tetrafluoroethane or difluoroacetyl chloride into contact with calcium chloride at a reaction enabling temperature. A production method of 2,2-difluoroethyl alcohol according to the present invention includes a catalytic reduction step of causing catalytic reduction of the difluoroacetyl chloride obtained by the above production method. By these methods, the difluoroacetyl fluoride can be efficiently converted to the difluoroacetyl chloride and to the 2,2-difluoroethyl alcohol.
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Paragraph 0092
(2013/03/26)
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- PROCESS FOR THE PREPARATION OF ENOLATE SALTS OF 4-FLUORO-2-HYDROXYMETHYLENE-3-OXO-BUTYRATES
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Enolate salts of 4-fluoro-2-hydroxymethylene-3-oxobutyrates of formula wherein R1 is C1-10 alkyl, R2 and R3 are independently hydrogen or fluorine, M is an alkali or alkaline earth metal, and n is 1 or 2, are prepared from enolate salts of the corresponding 4-fluoro-3-oxobutyrates and carbon monoxide. The enolate salts of formula I can be alkylated or acylated to obtain the corresponding enol ethers and esters. The 4-fluoro-3-oxobutyrate starting material can be prepared from 1,1-difluoroethyl methyl ethers by SbF5-catalyzed fluoromethane elimination followed by halogen exchange with lithium chloride, reacting the thus obtained fluoroacetyl chloride with ketene and quenching with the appropriate alcohol R1-OH.
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Page/Page column 12-13
(2012/02/02)
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- METHOD FOR PRODUCING DIFLUOROACETIC ACID ESTER
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A production method of a difluoroacetic acid ester according to the present invention includes at least: a reaction step of obtaining a liquid by reaction of an alcohol represented by ROH with difluoroacetic acid fluoride (CHF2COF) in the presence of an amide compound of the following formula (1) or a sulfone compound of the following formula (2) as a hydrogen fluoride trapping agent; and a distillation step (A) of extracting a difluoroacetic acid ester represented by CHF2COOR by distillation of the reaction liquid obtained in the first step. In the present production method, there occurs no deterioration in the yield of the product due to the inherent generation of hydrogen fluoride as a by-product during the esterification reaction of difluoroacetic acid fluoride.
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Page/Page column 8-9
(2012/12/13)
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- Method For Preparing Difluoroacetic Acid and Salts Thereof
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The invention relates to a method for preparing difluoroacetic acid and the salts thereof. The invention also relates to the preparation of difluoroacetyl fluoride used as an intermediate product in the preparation of difluoroacetic acid. The method for preparing difluoroacetic acid according to the invention is characterised in that the same comprises the step of preparing difluoroacetyl fluoride by reacting dichloroacetyl chloride with hydrofluoric acid in a gaseous phase and in the presence of a chromium-based catalyst, followed by the step of hydrolysing the difluoroacetyl fluoride thus obtained.
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Page/Page column 2-3
(2011/04/18)
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- Preparation of difluoroacetic acid fluoride and difluoroacetic acid esters
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A method for preparing difluoroacetic acid fluoride, which comprises reacting a 1-alkoxy-1,1,2,2-tetrafluoroethane of the formula HCF2 CF2 OR1 wherein R1 is a C1-4 alkyl group in a gas phase in the presence of a metal oxide catalyst.
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- Synthesis of Pentafluoroethyl Trifluoroacetate by Low-Temperature Direct Fluorination
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Ethyl acetate was perfluorinated by direct fluorination in the presence of cesium fluoride, affroding pentafluoroethyl trifluoroacetate in excellent yield.In the reaction pathway, the dimerization of trifluoroacetyl fluoride with cesium fluoride gives pentafluoroethyl trifluoroacetate.
- Akimura, Takashi,Shibakami, Motonari,Tamura, Masanori,Kurosawa, Shigeru,Sekiya, Akira
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p. 2454 - 2456
(2007/10/02)
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- Synthesis of functionalized polyfluoroalkyl hypochlorites and fluoroxy compounds and their reactions with some fluoroalkenes
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Several new polyfluoroalkyl hypochlorites and fluoroxy compounds containing Cl, H and Br in the alkyl group have been prepared and characterized by 19F NMR, 1H NMR and IR spectroscopies and by their reactions with fluoroalkenes to produce new polyfluoroethers.The novel compounds are prepared by the CsF-catalyzed addition of F2 or ClF to the C=O bond in CF3C(O)CF2Cl, ClCF2C(O)CF2Cl, and their derivatives HCF2C(O)CF3 and HCF2C(O)CF2Cl.Compounds containing an α-CF3 group exhibit enhanced thermal stability.New fluoroxy compounds and hypochlorites have also been prepared from the acid fluorides CF3-CFX-C(O)F (X = Cl, Br), which are obtained by the ring-opening reaction of hexafluoropropene oxide with (CH3)3SiCl, LiBr and (C2H5)3SiBr.These -OX compounds behave similarly to previously known materials with two α-F atoms, decomposing quickly at room temperature to COF2 and haloalkanes.
- Randolph, Bruce B.,DesMarteau, Darryl D.
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p. 129 - 150
(2007/10/02)
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- TRANSFORMATION D'OXYDES D'ALKYLES ET DE POLYFLUOROALKYLES PAR LES ACIDES DE LEWIS. INFLUENCE DES RADICAUX ALKYLES.
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The generation of perfluoroalkanoyl fluorides from perfluoroalkyl ethers by Lewis acids RHOCF2RF -> FRH + RFCOF depends mainly upon the nature of the alkyl RH radical.It is necessary to use RH groups with donor character and also electrophilic groups present on the radicals can facilitate the breaking of the RH-O bond.As examples, ethers with Me3SiCH2CH2 or CH2=CH-CH2 groups allowed reactions to occur readily at room temperature or below using common Lewis acids such as ZnCl2, BF3-Et2O, AlCl3.
- Nguyen, Thoai
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- Catalytic Conversion of Fluoroalkyl Alkyl Ethers to Carbonyl Compounds
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Fluoroalkyl alkyl ethers are generally available by attack of alkoxide ion on fluoro olefins.In the presence of Lewis acid catalysts, such methyl and ethyl ethers have now been found to lose methyl or ethyl fluoride, respectively, to give fluorinated carbonyl compounds.The carbonyl compounds include acid fluoride, ketone, keto ester, vinyl ketone, acyl ketene, ketene, and acryloyl fluoride.
- England, David C.
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p. 4007 - 4008
(2007/10/02)
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- Preparation of fluorocarbonyl compounds
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Fluorinated carbonyl compounds are prepared by contacting a fluorinated methyl or ethyl ether containing at least one methoxylated carbon atom-containing group selected from: --CF2 OR3, =CFOR3, STR1 wherein R3 is CH3 or C2 H5, with a catalyst selected from: SbX5, TaX5, NbX5, AsX5, BiX5, TiX4, ZrX4, HfX4, FeX3, mixtures of SbX3 and SbX5, ZM'X'6, and mixtures of ZM'X'6 and M'X5 where X, independently, is F, Cl, Br or I, X' is F or Cl; and Z is H, NO, O2, alkali metal or NY4 where Y, independently, is H or alkyl of 1 to 6 carbon atoms, and M' is Sb or As at a temperature of -20° to 200° C.
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