- Transformation de l'hexafluoropropene en alcool trifluoroallylique, precurseur des α-fluoroacrylates
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The fluoroacryloyl fluoride precursor of α-fluoroacrylic acid esters can arise from an allylic transposition of trifluoroallylic alcohol of which two methods of preparation are presented.In the first, dehydrofluoration of the alcohol CF3CFHCH2OH (4) is used.This alkohol is generated from the ester CF3CFHCOOC2H5 (3).In the second, dehalogenation of the alcohol CF3CFBrCH2OH (10) by zinc is used.The latter is formed by the selective reduction of the ester CF3CFBrCOOC2H5 (9). - Keywords: 2H-Tetrafluoropropanoic acid ester; 2H-Tetrafluoropropanol-1; Trifluoroallylic alcohol; α-Fluoroacryloyl fluoride; NMR spectroscopy
- Nguyen, Thoai,Wakselman, Claude
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- A 2-bromo -2, 3, 3, 3- four fluorine propionic acid method for synthesis of ethyl
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The invention relates to a synthetic method of 2-bromine-2,3,3,3-tetrafluoropropionic acid ethyl ester. 2,3,3,3-tetrafluoropropionic acid is taken as an initial raw material, a brominating agent is used for substituting hydrogen on a carbon atom at a site 2, so that the 2-bromine-2,3,3,3-tetrafluoropropionic acid is obtained, and then reaction is carried out on concentrated sulfuric acid and ethyl alcohol, so that the 2-bromine-2,3,3,3-tetrafluoropropionic acid ethyl ester is obtained. The synthetic method of the 2-bromine-2,3,3,3-tetrafluoropropionic acid ethyl ester has the advantages that reaction conditions are simple and mild, the 2-bromine-2,3,3,3-tetrafluoropropionic acid ethyl ester target product can be obtained through reaction in two steps, and the total yield is 75%.
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Paragraph 0021; 0022
(2017/03/08)
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- Reactions involving hexafluoropropylene oxide: Novel ring opening reactions and resolution of a racemic mixture of a bromofluoro ester, ultrasound mediated Reformatsky reactions and stereoselectivity
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A novel ring opening reaction of hexafluoropropylene oxide (HFPO) 1 with lithium bromide/zinc bromide and subsequent reaction of the resulting acyl fluoride with primary and secondary alcohols gave bromofluoro esters 2, 3, 4 and 7. Reaction of the corresponding acyl fluoride with water leads to acid 9 which on treatment with dehydroabietylamine 10 gave the diastereomeric salt 11. Resolution of 11 and subsequent hydrolysis and esterification reactions led to enantiomerically pure ester 12. Reformatsky reactions with 2 were studied which gave the alcohols 6 and 5. A Reformatsky reaction of 12 with formaldehyde afforded an alcohol 13 which is indicated by NMR spectroscopy in the presence of a chemical shift reagent to have proceeded stereoselectively.
- Coe, Paul L.,Loehr, Marianne,Rochin, Christophe
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p. 2803 - 2811
(2007/10/03)
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