- A rationally designed perfluorinated host for the extraction of PFOA from water utilising non-covalent interactions
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Perfluorooctanoic acid (PFOA) is a persistent organic pollutant and widespread in the environment. Three hosts have been synthesized based upon the formation of a fluorous cavity and hydrogen bonding receptors with the aim of extracting PFOA from water into organic solvents. The hosts based upon a calix[4]arene functionalized at the lower rim with amide groups and fluorous ponytails are effective for the quantitative removal of PFOA. Modification to a partial cone or a trisaminoamine framework reduces the conformational rigidity and lowers the extraction efficiency. A comprehensive NMR spectroscopic analysis both in solution and the solid state, along with other characterization techniques, has elucidated the stoichiometry of the host:guest species and the binding constants have been measured. A computational study has given further insight into the binding modes and corroborated the spectroscopic measurements.
- Omorodion, Harrison,Palenzuela, Miguel,Ruether, Manuel,Twamley, Brendan,Platts, James A.,Baker, Robert J.
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Read Online
- Photocatalytic amidation and esterification with perfluoroalkyl iodide
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The successful generation of perfluoroalkyl radicals (Rf˙) through photoredox catalysis has inspired us to investigate the preparation of various organofluorine species. In this work, visible light-induced photocatalytic reactions for the preparation of perfluoroalkyl amides and esters from the corresponding amines and alcohols using different types of triplet emitters as photocatalysts have been studied. The effects of the excited-state characteristics and redox potentials of the photocatalysts have been elucidated. Under optimized reaction conditions, these reactions can be performed successfully with different types of amines or alcohols and perfluoroalkyl iodides. Detailed mechanistic studies based on emission quenching experiments have been performed to study the photocatalytic cycles as well as the role of the different reagents. The proposed mechanism has also been examined by DFT calculations.
- Xiao, Yelan,Chun, Yuen-Kiu,Cheng, Shun-Cheung,Ng, Chi-On,Tse, Man-Kit,Lei, Ngai-Yu,Liu, Ruoyang,Ko, Chi-Chiu
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p. 556 - 562
(2021/02/09)
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- Preparation method of fluorine-containing carboxylic acid
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The invention discloses a preparation method of fluorine-containing carboxylic acid. The method comprises the following steps: reacting fluorine-containing carboxylate used as a raw material with an acylating chlorination reagent to obtain a corresponding mixture of fluorine-containing acyl chloride and fluorine-containing anhydride, and hydrolyzing and drying the mixture of fluorine-containing acyl chloride and fluorine-containing anhydride to obtain high-purity fluorine-containing carboxylic acid. The method provided by the invention is suitable for post-treatment of fluorine-containing carboxylic acid prepared by a fluorine-containing olefin (monoolefine, diene, cycloolefin and the like) oxidation method, replaces the traditional strong acid acidification and ether continuous extractionprocess, and is simpler, more convenient and more applicable; and the method can also be used for recovering and purifying a fluorine-containing carboxylate emulsifier. The purity of the fluorine-containing carboxylic acid prepared by the method can reach 98% or above.
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Paragraph 0056-0058
(2020/07/12)
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- Synthetic method of medicine raw material namely 3-methyl perfluorooctanoic acid
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The invention relates to a synthetic method of a medicine raw material namely 3-methyl perfluorooctanoic acid. The synthetic method comprises the following steps of putting raw materials of caprylyl chloride, hydrogen fluoride and a few n-butyl sulfuric acid into an electrolytic cell, performing electrifying (the voltage is 5-8V) at 20-25 DEG C, neutralizing an electrolytic product with an alkali, then sequentially performing acidification and methylation, and finally performing distillation so as to obtain the 3-methyl perfluorooctanoic acid. The synthetic method of the medicine raw material namely the 3-methyl perfluorooctanoic acid disclosed by the invention is simple, efficient, safe to operate and quite practical in specific production.
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Paragraph 0006
(2017/01/19)
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- Hydrolysis of p-nitrophenyl perfluoroctanoate in mixed surfactant systems
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The kinetics of the hydrolysis reaction of p-nitrophenyl perfluoroctanoate were studied in the presence of different amphiphilic systems: two hydrocarbon surfactants (sodium dodecyl sulfate, SDS, and polyoxyethylene(23)lauryl ether, Brij-35), a perfluorinated detergent (perfluorononanoic acid, PFNA) and in mixtures of SDS-PFNA and Brij-35-PFNA. The study was performed at different compositions of the mixtures (characterized by the molar fraction of PFNA, αPFNA), and for each αPFNA the concentration was varied over a wide range. The kinetic probe p-nitrophenyl perfluoroctanoate showed a very strong interaction with the surfactants. In the presence of the mixed surfactants, the behaviour of the probe changed dramatically with the composition of the mixtures, which indicates that this substrate is very sensitive to the effect of the micellar media, being a very good molecule to study these types of surfactant systems. The use of the studied ester allowed us to confirm the presence of two different aggregates in the mixture Brij-35-PFNA as was previously observed with other techniques. The presence of hydrocarbon-rich micelles at low αPFNA, as well as perfluorinated rich micelles at high αPFNA was also confirmed. The kinetic behaviour of p-nitrophenyl perfluoroctanoate in SDS-PFNA mixtures fully agreed with our previous description of the aggregates formed in this system. The presence of a practically pure PFNA micelle at high αPFNA could be also demonstrated from the kinetic results.
- Torres, Maria Florencia,De Rossi, Rita H.,Fernandez, Mariana A.
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p. 28606 - 28614
(2014/07/22)
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- METHODS OF PREPARING FLUORINATED CARBOXYLIC ACIDS AND THEIR SALTS
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A method for preparing fluorinated carboxylic acids and theirs salts is described comprising subjecting a fluorinated alcohol of the general formula (A): A-CH2-OH to at least one first and at least one second oxidizing agent to produce a highly fluorinated carboxylic acid or their salts of the general formula (B): A-COO M+, wherein M+ represents a cation and wherein A in formulas (A) and (B) is the same and A represents the residue: Rf-[0]p-CX"Y"-[0]m-CX'Y'-[0]n-CXY- wherein Rf represents a fluorinated alkyl residue which may or may not contain one or more catenary oxygen atoms, p, m and n are independently from each other either 1 or O, X, X', X", Y, Y' and Y" are independently from each other H, F, CF3, or C2F5 with the proviso that not all of X, X', X", Y, Y' and Y' ' are H; or A represents the residue: R-CFX- wherein X and R are independently selected from a hydrogen, a halogen, or an alkyl, alkenyl, cycloalkyl, or aryl residue, which may or may not contain one or more fluorine atoms and which may or may not contain one or more catenary oxygen atoms; wherein said at least one first oxidizing agent is a compound that can be converted, by action of the second oxidizing agent, into a reactive species capable of oxidizing the fluorinated alcohol.
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Page/Page column 35-36
(2011/05/06)
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- Efficient mineralization of hydroperfluorocarboxylic acids with persulfate in hot water
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The persulfate (S2O82-)-induced decomposition of hydroperfluorocarboxylic acids (H-PFCAs), that is, HCnF2nCOOH (n = 4, 6, and 8), in hot water was investigated, and the results were compared with the
- Hori, Hisao,Murayama, Misako,Inoue, Naoko,Ishida, Kyoko,Kutsuna, Shuzo
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experimental part
p. 131 - 136
(2010/08/20)
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- PROCESS FOR THE SYNTHESIS OF POLYFLUOROCARBOXYLIC ACIDS
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The invention relates to a process for the preparation of the acids of formula: Rf(CX2CF2)m-1CX2COOH by reaction of the sulphinates of formula: Rf(CX2CF2)m SO2Na with a radical initiator, in which formulae m is an integer from 2 to 6, Rf is a linear or branched perfluoroalkyl group comprising from 1 to 6 carbon atoms, X= F or H. According to one advantageous form, Rf is a linear or branched perfluoroalkyl group comprising from 2 to 4 carbon atoms. According to another advantageous form, m is an integer from 3 to 5.
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Page/Page column 7-8
(2008/06/13)
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- METHOD FOR PRODUCING FLUORINE-CONTAINING CARBOXYLIC ACID OR FLUORINE-CONTAINING CARBOXYLATE
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PROBLEM TO BE SOLVED: To provide a method for producing fluorine-containing carboxylic acid or fluorine-containing carboxylate. SOLUTION: The fluorine-containing carboxylic acid [when M in formula (II) is H] or the fluorine-containing carboxylate [when M in formula (II) is a metal], represented by general formula (II) Rf-COOM [wherein Rf is a 1-20C fluoroalkyl; and M is H or the metal], is produced by reacting a fluorine-containing alkene of general formula (I) Rf-CF=CH-R [wherein Rf is the same as represented in formula (II); and R is a (substituted) alkyl] with an oxidizer.
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Page/Page column 10-11
(2008/06/13)
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- PROCESS FOR PREPARING FLUOROCARBOXYLIC ACIDS
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A fluorocarboxylic acid preparation process continuously carries out acidification reaction treatment and washing treatment, and includes subjecting a fluorocarboxylate-containing aqueous solution to acidification reaction treatment in the presence of sulfuric acid so as to form a sulfate-containing fluorocarboxylic acid phase; and subjecting the fluorocarboxylic acid phase to washing treatment using an aqueous sulfuric acid solution.
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- Changing mechanisms in the β-cyclodextrin-mediated hydrolysis of phenyl esters of perfluoroalkanoic acids
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The rate of hydrolysis of esters CF3(CF2) nCOOPh (1 (n = 1), 2 (n = 2), and 3 (n = 6)) was measured at pH 6.00 and at pH higher than 9.00 in the presence of β-cyclodextrin (β-CD). For compounds 1 and 2 the reaction rate decreases as the β-CD concentration increases, and they show saturation effects at all pH. It is suggested that the substrate forms an inclusion complex with cyclodextrin. Analysis of the rate data allows calculation of the association equilibrium constant, KCD, the rate constant for the reaction of the included compound, kc, and KTS which is the hypothetical association equilibrium constant for the transition state of the cyclodextrin-mediated reaction. The dependence of log KCD and log KTS with the number of atoms in the chain is different. We suggest that the reactions of 1 and 2 take place with the perfluorinated alkyl chain included in the cavity, whereas the transition state for the reaction of phenyl trifluoroacetate involves a complex with the aryl ring inside the cavity. At low pH the inhibition comes from the protection of the carbonyl group toward nucleophilic attack by water. In basic pH the reaction of HO- as an external nucleophile is also inhibited. The cyclodextrin-mediated reaction involves the ionized OH group at the rim of the cyclodextrin cavity with poor efficiency due to an unfavorable orientation of the substrate in the complex. On the other hand, the reaction of compound 3 is strongly accelerated by cyclodextrin because the association of the substrate with cyclodextrin competes with the monomer-aggregate equilibrium and at high enough cyclodextrin concentration the main species present in solution is the complex between 3 and cyclodextrin.
- Fernandez, Mariana A.,De Rossi, Rita H.
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p. 6887 - 6893
(2007/10/03)
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- Methods and compositions for sealing tissue leaks
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The invention provides methods and compositions that are useful for adhering biological and/or synthetic tissues, sealing fluid and/or gaseous leaks in biological and/or synthetic tissues, and preparing implants useful for delivery of a bioactive molecule such as a drug, for bulking applications, or for tissue prostheses. The present invention also relates to bio-erodable adhesive or occluding compositions and methods of using the same.
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- Treatment of skin conditions by use of PPAR alpha activators
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Disorders of the skin and mucous membrane that have a disrupted or dysfunctional epidermal barrier are treated or prevented by topical application of compounds that are either activators of the farnesoid X receptor, activators of the peroxisome proliferator-activated receptor alpha , and oxysterol activators of the LXR alpha receptor. The same compounds are also effective in treating disorders of epidermal differentiation and proliferation.
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- Method for preparation of perfluoroalcanecarboxylic and perfluoroalkanesulfonic acids
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PCT No. PCT/FR96/02079 Sec. 371 Date Sep. 4, 1998 Sec. 102(e) Date Sep. 4, 1998 PCT Filed Dec. 24, 1996 PCT Pub. No. WO97/24309 PCT Pub. Date Jul. 10, 1997The invention consists of a new method for preparing perfluoroalcanecarboxylic and perfluoroalcanesulfonic acids in which ozone is made to react, in a protic environment, upon a perfluoroalkyl chain comprising at least one oxydizable chemical group.
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- Synthese de 3-perfluoroalkylprop-1-enes RF-CH2-CH=CH2
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The reactions of perfluoroalkyl iodides with allylbromide or chloride, in the presence of solid potassium hydroxide KOH give 3-perfluoroalkylprop-1-enes RFCH2CH=CH2 in good yields under mild conditions. This reaction represents a synthetically viable and convenient route to such compounds.
- Rubio,Blancou,Commeyras
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p. 171 - 175
(2007/10/03)
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- Multiple pathways in cyclodextrin-catalyzed hydrolysis of perfluoroalkylamides
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The hydrolysis of p-nitroanilide of perfluoroalkanoic acids, CF3(CF2)nCO-, with n = 1, 2, 3, 5, 6, and 7, 1a-f, was studied in the presence of β-cyclodextrin (CD). All reactions were catalyzed by CD through the formation of a 1:1 and 1:2 inclusion complexes. The association equilibrium constants for the 1:1 complexes were dependent on the number of carbons of the fluoroalkyl chain, whereas those of the 1:2 complexes were almost independent. These results indicate that, in the former case, the perfluoroalkyl chain is included, while in the latter, the CD unit encloses the aryl ring. For compounds 1a,b both complexes were more reactive than the substrate itself. The ratio of the reaction of complexed to uncomplexed substrate had its highest value for 1a in the case of the 1:1 complex, and for 1b, the 1:2 complex. This is attributed to the geometry of the complexes. Although compounds 1c-e reacted at the same rates in the free or 1:1 complexed form, CD accelerated the reactions because of an increase of the pKa of the substrate, which results in a higher concentration of the neutral reactive substrate at the same pH. Compound 1f formed aggregates even at 10-6 M concentration, and CD-induced deaggregation resulted in catalysis of the reaction.
- Granados, Alejandro,De Rossi, Rita H.
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p. 3690 - 3696
(2007/10/02)
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- Chlorotrifluoroethylene-derived fluids. I. Model compound synthesis
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A series of chlorofluoroalkanes having chlorines on adjacent carbon atoms has been prepared, i.e. n-C5F11CFClCCl3, n-C6F13CFClCCl3, n-C5F11CFClCFCl2, n-C6F13CFClCFCl2, n-C5F11CFClCF2Cl, n-C2F5CFClCFClC3F7 and n-CF3CFClCFClC4F9, by a combination of halogen exchange, dehalogenation and chlorine addition reactions.An attempt to synthesize n-C6F13CFClCF2CFCl2 by the coupling of n-C6F13CFClI with an excess of ICF2CFCl2 under UV radiation in the presence of Hg gave only n-C6F13CFClCFClC6F13 together with CFCl2CF2CF2CFCl2.Under parallel conditions from n-C6F13CFClI and CF2ClCFClI, n-C6F13CFClCFClCF2Cl was obtained in 48percent yield.
- Paciorek, K. J. L.,Kratzer, R. H.,Nakahara, J. H.,Lin, W.-H.
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p. 271 - 282
(2007/10/02)
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- Reaction of Perfluoroalkanesulfinates with Allyl and Propargyl Halides. A Convenient Synthesis of 3-(Perfluoroalkyl)prop-1-enes and 3-(Perfluoroalkyl)allenes
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The reaction of perfluoroalkanesulfinates, RfCF2SO2Na, with allyl and propargyl halides, in the presence of (NH4)2S2O8, gave 3-(perfluoroalkyl)prop-1-enes (RfCH2CH=CH2) and 3-(perfluoroalkyl)allenes (RfCH=C=CH2), respectively, in good yield.Evidence is presented for a radical addition-elimination mechanism for the reaction.The reaction represents a synthetically viable and convenient route to such compounds.
- Hu, Chang-Ming,Qing, Feng-Ling,Huang, Wei-Yuan
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p. 2801 - 2804
(2007/10/02)
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- SYNTHESIS OF PERFLUOROALKYL CARBOXYLIC ACIDS BY REACTION OF PERFLUOROALKYL IODIDES WITH ELECTROGENERATED SUPEROXIDE ION
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The electrogenerated superoxide ion O2 is shown to react with perfluoroalkyliodides to afford F-alkyl carboxylic acids.A mechanism is proposed on the basis of the results obtained in preparative experiments and by cyclic voltammetry.
- Amatore, C.
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p. 357 - 379
(2007/10/02)
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- Process for the preparation of extensively fluorinated alkyl bromides
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A process for the preparation of extensively fluorinated alkyl bromides from the corresponding iodides is described in which, in a dipolar aprotic solvent, a bromide which is present as a salt of an alkali metal, alkaline earth metal, copper or substituted or unsubstituted amonium is reacted with an extensively fluorinated alkyl iodide at 120° to 200° C. The reaction can be carried out at -10° to +120° C., in some cases with improved yields if it is carried out in the presence of an alkali metal salt of at least one hydroxyalkanesulfinic acid having 1 to 5 carbon atoms. The novel process enables uncomplicated apparatuses to be used without particular safety measures and presents no corrosion problems.
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- Photooxidation of Perhalofluorosulfinates. A Simple and Effective Method for the Synthesis of Perhalofluorocarboxylic Acids and Their Esters from the Corresponding Sulfonyl Fluorides
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Photooxidation promoted by ultraviolet irradiation of perhalofluorosulfinates afforded a simple and effective method for the synthesis of perhalofluorocarboxylic acids and their esters from the corresponding sulfonyl fluorides.
- Hu, Chang-Ming,Xu, Ze-Qi,Huang, Wei-Yuan
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p. 145 - 148
(2007/10/02)
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- A NEW METHOD FOR THE PREPARATION OF PERFLUOROCARBOXYLIC ACIDS
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The reaction of both primary perfluoroalkyl iodides and bromides containing 3-12 carbon atoms with a rongalite-NaHCO3 reagent in aqueous dipolar aprotic solvents, such as DMF or DMSO, has been investigated.The reaction gave sodium perfluorocarboxylates in 51-86percent yields, and these were transformed to the respective perfluorocarboxylic acids by treatment with sulfuric acid.This provides a new method for the synthesis of perfluorocarboxylic acids.
- Huang, Bing-Nan,Haas, A.,Lieb, M.
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- A NEW GENERAL SYNTHESIS ROUTE TO 1,1,1-TRIHALOPOLYFLUOROALKANES
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1,1,1-Trichloro- and tribromo polyfluoroalkanes have been synthesized from perfluoroalkyl iodides and anhydrous aluminium chloride and bromide respectively.The reaction is also applicable to perfluoroalkylether iodides, though varying amounts of by-products are formed depending on the structure of the starting iodode.
- Eapen, K. C.,Eisentraut, K. J.,Ryan, M. T.,Tamborski, C.
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p. 405 - 416
(2007/10/02)
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- Method for production of fluorine-containing aromatic derivative
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A fluorine-containing aromatic derivative is produced by causing a di(haloacyl)peroxide to react upon benzene, a mono-substituted benzene, naphthalene, or a mono-substituted naphthalene thereby introducing an X(CF2)n -group into the benzene ring or the naphthalene ring.
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- THE ELECTROCHEMICAL FLUORINATION OF OCTANOYL FLUORIDE WITH ELECTROLYTE CIRCULATION
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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.
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p. 423 - 440
(2007/10/02)
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