- Yield improvement in the electrochemical production of pefluorooctanoic acid
-
The possibility of obtaining real yield improvements in the industrial electrochemical production of perfluorooctanoic acid is discussed on the basis of recent experimental data obtained using perfluorohexyl acetyl chloride in place of octanoyl chloride as a starting material.In particular, the effect of the non-formation of cyclic byproducts on the yield of perfluoro-octanoic acid has been examined, as well as considering previous results obtained starting from a different partially fluorinated precursor, 4-perfluorobutyl butanoyl chloride.The yield of perfluoro-octanoic acid from perfluorohexyl acetyl chloride was less than expected, because of an accompanying increase in perfluoro-n-heptane formation.
- Napoli, M.,Scipioni, A.,Gambaretto, G. P.,Carlini, F. M.,Bertola, M.
-
-
Read Online
- THE ELECTROCHEMICAL FLUORINATION OF OCTANOYL FLUORIDE WITH ELECTROLYTE CIRCULATION
-
A modification to the standard method of electrochemical fluorination is described which embodies a forced flow of electrolyte through the electrode pack.A preliminary study of flow characteristics through an electrode pack was carried out.Good yields of perfluorooctanoyl fluoride and associated perfluorinated products are reported.The nature of the anode surface was studied before and after fluorination by scanning electron microscopy.
- Lines, D.,Sutcliffe, H.
-
-
Read Online
- A Lewis acid catalytic process for preparing fluorocarboxylic acid halides
-
Selected Group III and Group V Lewis acids were found to catalyze the isomerization and rearrangement of halosulfonyldifluoromethyl group (Rf-CF2SO2X, where X is either chlorine or fluorine) to form fluorocarboxylic acid halides (RfCOX). Fluorodesulfoxylation of the halosulfonyldifluoromethyl group yielded SOF2 as one of the two sulfur-containing oxides. Product analysis would suggest that both Lewis acid catalyzed and halogen exchange reactions are occurring and are dependent upon the starting halosulfonyldifluoromethyl material and Lewis acid.
- Behr,Cheburkov
-
p. 369 - 372
(2007/10/03)
-
- THE SYNTHESIS OF PERFLUORO HIGHLY BRANCHED HETEROCYCLIC FLUORINE COMPOUNDS BY DIREKT FLUORINATION
-
The direct fluorination of hexamethyleneimine, heptamethyleneimine, 2,6-dimethylmorpholine, thiomorpholine, 1,4-dimethylpiperazine and piperazine produced the corresponding perfluoinated products.The 19F NMR spectrum of perfluoro N,N'-difluoropiperazine was found to be temperature-dependent.
- Lin, Wen-Huey,Lagow, Richard J.
-
-
- ANALYSIS OF THE PRODUCTS FROM THE ELECTROCHEMICAL FLUORINATION OF OCTANOYL CHLORIDE
-
The perfluorinated products from the electrochemical fluorination of octanoyl chloride were analyzed using several techniques.Cappillary gas chromatography was used for quantitative analysis of the desired product, perfluorooctanoyl fluoride, and for perfluorinated cyclic ether by-products.Isopropyl ether was an effective solvent, and ethylbenzene served as an internal standard.Acidimetric titration was used to qualify the amount of acid derivative products present in the sample.Since the products have limited solubility in water, alternative solvents were developed.Taking advantage of the facile hydrolysis of the acyl fluoride product, the perfluorinated acid was isolated.Details of the application of these chemical techniques to perfluorinated products and the corresponding results will be discussed.
- Prokop, H.W.,Zhou, H-J,Xu, S-Q,Wu, C-H,Liu, C. C.
-
p. 277 - 290
(2007/10/02)
-
- ELECTROCHEMICAL FLUORINATION OF 4-(PERFLUORO-n-BUTYL)-n-BUTANOYL CHLORIDE
-
Electrochemical fluorination of 4-(perfluoro-n-butyl)-n-butanoyl chloride produces perfluorooctanoyl fluoride in higher yields than those obtained from n-octanoyl chloride, which is the usual starting material.In particular, one of the by-products of the industrial process, the cyclic perfluoroether perfluoro-2-propyl-tetrahydropyran, is not formed.Also the other by-products, except fluorocarbon perfluoro-n-heptane, are produced in lower amounts.These results are discussed and a mechanism is suggested.
- Napoli, M.,Conte, L.,Gambaretto, G. P.,Carlini, F. M.
-
p. 213 - 224
(2007/10/02)
-
- ELECTROCHEMICAL FLUORINATION USING POROUS NICKEL AND FOAM NICKEL ANODES
-
This work set out to examine the reasons behind some of the problems associated with ECF, namely, lack of reproducibility, low chemical yields, poor selectivity and low current densities, with a view to ameliorating these shortcomings and making the process more attractive to the chemical industry.The approach was to study the chemistry under controlled conditions of potential, reactant concentration, temperature, etc., and to analyse the results in terms of product structure, distribution and yield.Two distinct stages in the process were identified, i) the conditioning of the electrode, and, ii) the fluorination of the organic substrate.These stages are described in detail in relation to two model systems investigated, the fluorination of propene using porous and foam nickel anodes, and the fluorination of the octanoyl chloride using nickel foam anodes.The scales of experiments ranged from 100 ml to 100 l cell capacities.General conclusions are derived and recommendations made for the more efficient operation of the process.
- Drakesmith, F. G.,Hughes, D. A.
-
p. 103 - 134
(2007/10/02)
-
- FREE RADICAL CHEMISTRY, PART 5. A NEW APPROACH TO THE SYNTHESIS OF PERFLUORINATED ETHERS
-
Fluorinations of the free-radical adducts of fluorinated alkenes, to ethers, over cobalt trifluoride are described and perfluorinated ethers are obtained at temperatures in excess of 400 deg C.The effect of structure on the formation of perfluoroethers is outlined.
- Chambers, Richard D.,Grievson, Brian,Drakesmith, Frederick G.,Powell, Richard L.
-
p. 323 - 340
(2007/10/02)
-
- FLUORINATIONS WITH COMPLEX METAL FLUORIDES PART 8. RING REARRANGEMENT IN THE FLUORINATIONS OF QUINOLINE WITH CAESIUM TETRAFLUOROCOBALTATE AND WITH COBALT(III) FLUORIDE
-
Fluorination of quinoline by caesium tetrafluorocobaltate at ca. 350 deg C afforded mainly a mixture of pentadecafluoro-2-azabicyclodec-1(2)-ene (E), and heptadecafluoro-1-azabicyclodecane (F), arising by skeletal rearrangement.Minor products were six polyfluorocyclohexapyridines (G-L) all with carbocyclic rings having the -(CF2)4 - moiety.Compound F was unreactive, but E was highly susceptible to nucleophiles, e.g. water and methanol.Isoquinoline was fluorinated similarly, but the only new product isolated was tridecafluoro-3-azabicyclodeca-1(6)-2-diene (R).The rearrangement occurring with quinoline prompted a re-examination of its fluorination by cobalt(III) fluoride.At ca. 350 deg C, compound F was the major product, with very little E: there were some ring-opened materials, the most important being tetradecafluoro-4-pentafluoroethyl-2-azaoct-2(Z)-ene (N).
- Plevey, Raymond G.,Rendell, Richard W.,Tatlow, John Colin
-
p. 413 - 428
(2007/10/02)
-
