- METHOD FOR PRODUCING 2-HALOGEN-ACRYLIC ACID ESTERS
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The present invention relates to a process for preparing 2-haloacrylic esters from 2-hydroxymethyl- or 2-halomethyl- or 2-chlorosulfinyloxymethyl-2-halomalonic diesters. The invention further provides novel 2-halomethyl-2-halomalonic diesters or 2-chlorosulfinyloxymethyl-2-halomalonic diesters which can be used for preparation of the 2-haloacrylic esters.
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- Preparation method of alpha-fluorinated acrylate
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The invention discloses a method for preparing alpha-fluorinated acrylate.The method comprises the steps that raw materials are dissolved into a first organic solvent at first, organic base or inorganic base is added, a hydroxyl protecting agent is added dropwisely on the condition of low temperature ranging from subzero 10 DEG C to 10 DEG C, the temperature is slowly increased to the room temperature to 100 DEG C after dropwise addition is completed, a heat preservation reaction is performed for 3-6 h, water is added for dissolving solids for organic phase washing and liquid separation, an organic phase is concentrated to be dry, the product is added into a second organic solvent, a polymerization inhibitor is added, heating is performed to reach 100-180 DEG C, a reaction is performed for 1-18 h, a mixed solution containing the product is distilled out, and then distillation purification is performed to obtain the alpha-fluorinated acrylate.The method is low in cost, easy to implement and low in equipment requirement, no extremely toxic substance is adopted as raw materials, the whole process is environmentally friendly, the yield is high, the product purity is good, and the method has economic value and is suitable for industrialization.
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Paragraph 0067; 0068
(2017/04/07)
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- PRODUCTION METHOD FOR ALPHA-FLUORO ACRYLIC ACID ESTERS
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An object of the present invention is to provide a process for producing α-fluoroacrylic acid esters at a high starting material conversion and a high yield. The present invention provides, as a means to achieve the object, a process for producing a compound represented by formula (1): wherein R2 and R2 are the same or different and each represent alkyl, fluoroalkyl, aryl optionally substituted with at least one substituent, halogen, or hydrogen; and R3 represents alkyl, fluoroalkyl, or aryl optionally substituted with at least one substituent, the process comprising step A ofreacting a compound represented by formula (2): wherein the symbols are as defined above, with carbon monoxide and an alcohol represented by formula (3): [in-line-formulae]R3—OH ??(3)[/in-line-formulae]wherein the symbol is as defined above, in the presence of a transition metal complex catalyst containing at least one bidentate phosphine ligand and a base to thereby obtain the compound represented by formula (1).
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Paragraph 0139; 0140
(2016/11/17)
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- Method for the preparation of compounds
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The invention provides a preparation method of a compound as described in the formula 1. The method comprises the steps of (1) contacting a compound as described in the formula 2 and a compound as described in the formula 3 in the existence of alkali to obtain a compound as described in the formula 4; and (2) directly contacting a reaction product obtained in the step (1) and paraformaldehyde to obtain the compound as described in the formula 1, wherein weak acid is added in the reaction product before the reaction product obtained in the step (1) is in contact with the paraformaldehyde so that the residual alkali in the reaction product can be neutralized. By using the method, the compound as described in the formula 1 can be effectively prepared.
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Paragraph 0099; 0100; 0102; 0103; 0104; 0105
(2017/04/03)
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- Α, α-difluoropropionic production of esters
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PROBLEM TO BE SOLVED: To provide a practical method of producing α,α-difluoro esters important as pharmaceutical and agricultural chemical intermediates. SOLUTION: The α,α-difluoro esters are produced by reacting α-halogeno-α-fluoro esters with salts or complexes comprising an organic base and hydrogen fluoride. Dehydrohalogenation of side reaction is controlled in the production method. Only α-fluoro-α,β-unsaturated esters of by-products are treated to be brought specifically into a high boiling-point, a boiling point difference gets remarkably large thereby between the α,α-difluoro ester of an objective product and the unsaturated ester of by-product, and a high purity product of the objective product is efficiently obtained by fractional distillation of a simple operation. The method is the practical method of producing the α,α-difluoro esters capable of solving a problem point in a prior technique. COPYRIGHT: (C)2012,JPOandINPIT
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Paragraph 0123-0125
(2016/10/10)
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- Designer HF-Based fluorination reagent: Highly regioselective synthesis of fluoroalkenes and gem -difluoromethylene compounds from alkynes
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Hydrogen fluoride (HF) and selected nonbasic and weakly coordinating (toward cationic metal) hydrogen-bond acceptors (e.g., DMPU) can form stable complexes through hydrogen bonding. The DMPU/HF complex is a new nucleophilic fluorination reagent that has high acidity and is compatible with cationic metal catalysts. The gold-catalyzed mono- and dihydrofluorination of alkynes using the DMPU/HF complex yields synthetically important fluoroalkenes and gem-difluoromethlylene compounds regioselectively.
- Okoromoba, Otome E.,Han, Junbin,Hammond, Gerald B.,Xu, Bo
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supporting information
p. 14381 - 14384
(2015/01/09)
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- Preparation of substituted 2-fluoroacrylic acid derivatives
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The present invention relates to a process for the preparation of substituted 2-fluoroacrylic acid derivatives.
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Page/Page column 5-6
(2012/11/13)
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- Expedient synthesis of α-substituted fluoroethenes
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A mild and efficient synthesis of 1-aryl-1-fluoroethenes from benzothiazolyl (aryl)fluoromethyl sulfones and paraformaldehyde, under DBU- or Cs2CO3-mediated conditions at room temperature, is described. A comparable diethyl fluoro(naphthalen-2-yl)methylphosphonate reagent does not react with paraformaldehyde under these mild conditions. The utility of the methodology for synthesis of terminal α-fluoroalkenes bearing electron-withdrawing functionalities is also shown.
- Mandal, Samir K.,Ghosh, Arun K.,Kumar, Rakesh,Zajc, Barbara
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supporting information; experimental part
p. 3164 - 3167
(2012/06/04)
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- Process for Preparation of 2-Fluoroacrylic Esters
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According to the present invention, there is provided a production process of a 2-fluoroacrylic ester including: a bromination step of converting a 2-fluoropropionic ester to a 2-bromo-2-fluoropropionic ester by reaction of the 2-fluoropropionic ester with a nitrogen-bromine bond-containing brominating agent in the presence of a radical initiator; and a dehydrobromination step of reacting the 2-bromo-2-fluoropropionic ester with a base. It is not necessary in this process to adopt very-low-temperature conditions and to use a stoichiometric amount of expensive reagent. The target 2-fluoroacrylic ester can be thus produced at low cost.
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Page/Page column 9
(2012/03/26)
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- Low-temperature 19F NMR spectroscopy of 1-fluoro-1-lithioethenes - Stability, shifts and unexpected coupling constants
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Half-lives and fluorine atom shifts of stabilized 1-fluoro-l-lithioethenes bearing hydrogen, fluorine, phenyl, and/or dimethylphenylsilyl groups in the β-positions have been determined by a low-temperature 19F NMR spectroscopy. Some 1-fluoro-1-lithioethenes displayed an exceptionally low value of the trans-3JFF coupling constant. Stereoselectivity of carbenoid formation, as well as an effect of configuration on the stability is discussed.
- Kvicala, Jaroslav,Hrabal, Richard,Czernek, Jiri,Bartosova, Ivana,Paleta, Oldrich,Pelter, Andrew
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p. 211 - 218
(2007/10/03)
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- Chemistry of 4-fluoroglutamic acid. Part 1. A critical survey of its syntheses: an attempt to optimize reaction conditions for large-scale preparation
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Synthetic methods for the preparation of 4-fluoroglutamic acid (1) are reviewed.The utility of every method for routine laboratory work is evaluated with respect to the accessibility of starting materials and reagents, the overall yields and also from the viewpoint of safety.Optimum reaction conditions are given for the selected pathway, suitable for large-scale synthesis.
- Tolman, V.
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p. 179 - 183
(2007/10/02)
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- Synthese von α-Fluoracrylsaeure und Derivaten
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Three new routes to derivatives of α-fluoracrylic acid, including a laboratory synthesis and a large-scale method, are reported.The processes are (i) addition of elementary fluorine to acrylic esters and subsequent elimination of HF; (ii) addition of difluorocarbene to isopropenyl methyl ether, oxidation via ring opening and dehalogenation; and (iii) "nitrofluorination" of 2,3-dichloropropene, hydrolysis and dechlorination.
- Gassen, K.-R.,Bielefeldt, D.,Marhold, A.,Andres P.
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p. 149 - 162
(2007/10/02)
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- Reduction-Olefination of Esters: A New and Efficient Synthesis of α-Fluoro α,β-Unsaturated Esters
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A reduction-olefination sequence has been used to convert esters to α-fluoro α,β-unsaturated esters.In the presence of diisobutylaluminum hydride, esters are reduced to aldehydes that react in situ with -Li+ to form the title compounds in good yield with high stereoselectivity.The reaction is applicable to aliphatic, aromatic, cyclic, unsaturated, perfluorinated, and partially fluorinated esters.The E/Z ratio of unsaturated esters formed in the reaction varies with the cations present in the reaction mixture.Solvents have very little influence on stereochemistry.The sequential transformation of PhC(O)OBun to (E)-PhCH=CFC(O)OEt and then to (E,E)-PhCH=CFCH=CFC(O)OEt illustrates the scope of this methodology, which introduces a fluorine atom adjacent to an ester functionality with concomitant elongation of the chain by two carbon atoms.
- Thenappan, Alagappan,Burton, Donald J.
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p. 4639 - 4642
(2007/10/02)
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- REACTION OF HALOGEN FLUORIDES. IX. SYNTHESIS OF DERIVATIVES OF α-FLUOROACRYLIC ACID
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New methods have been proposed for the preparation of derivatives of α-fluoroacrylic acid by the substituent fluorination of 1,2-dibromo-3-chloropropane and methyl 2,3-dibromo-2-chloropropanoate with bromine trifluoride.
- Boguslavskaya, L. S.,Chuvatkin, N.,Morozova, T. V.,Panteleeva, I. Yu.,Kartashov, A. V.,Sineokov, A. P.
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p. 1060 - 1064
(2007/10/02)
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- SYNTHESIS OF 2-FLUOROPROPENOIC ACID DERIVATIVES
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A method is described for the synthesis of 2-fluoropropenoic acid esters, amides, and nitrile from the corresponding derivatives of 2-fluoro-3-(4-toluenesulfonyloxy)propanoic acid by heating with potassium phtalimide in vacuo.The free acid Ia and its chloride have also been synthetized.The reactivity of esters and nitrile of acid Ia has been verified by the Michael addition of diethyl acetamidomalonate to these compounds.
- Tolman, Vladimir,Spronglova, Pavla
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p. 319 - 326
(2007/10/02)
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