- On the formation of surface active by-products during the electrochemical fluorination of tertiary amines
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The electrochemical fluorination (ECF) of 2-phenyl-3,4-dimethylmorpholine led to the solubilization of the perfluoro products and HF foaming, which may be traced back to the formation of partially fluorinated, HF-soluble compounds which exhibit surface activity in HF.Some of the perfluoro products contain an asymmetric carbon atom attached directly to a cyclohexyl ring.This asymmetric centre leads to the non-equivalence of the fluorines bound to carbon atoms 2 and 6, respectively, of the cyclohexyl ring allowing them to be distinguished in the 19F NMR spectra.
- Dimitrov, Anton,Ruediger, Stephan,Pauli, Jutta
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- Simons electrochemical fluorination of substituted homopiperazines(hexahydro-1,4-diazepines) and piperazines
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Simons electrochemical fluorination (ECF) of 1,4-dimethyl-1,4-homopiperazine, methyl 4-ethylhomopiperazin-1-ylacetate and 1,4-bis(methoxycarbonylmethyl)-1,4-homopiperazine was studied. For comparison, ECF of three piperazines with a N-(methoxycarbonylmethyl) group(s) was also studied. ECF of 1,4-dimethyl-1,4-homopiperazine gave a low yield of corresponding perfluoro(1,4-dimethyl-1,4-homopiperazine) together with perfluoro(2,6-diaza-2,6-dimethylheptane) as the major product. Corresponding perfluoro(homopiperazines) with mono- and/or di-(fluorocarbonyldifluoromethyl) groups [-CF2C(O)F] at the 1- and/or 4-position were formed in low yields from methyl 4-ethylhomopiperazin-1-ylacetate and 1,4-bis(methoxycarbonylmethyl)-1,4-homopiperazine, respectively. These new seven-membered perfluoro(1,4-dialkyl-1,4-homopiperazines) were accompanied by the formation of mono- and/or di-basic linear perfluoroacid fluorides resulting from the C-C bond scission at the 2- and 3-positions of the ring. From mono- and/or di-N-(methoxycarbonylmethyl)-substituted piperazines, corresponding perfluoropeperazines having the acid fluoride group(s) were formed in low yields.
- Abe, Takashi,Baba, Hajime,Fukaya, Haruhiko,Tamura, Masanori,Sekiya, Akira
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- An efficient high-yield synthesis for perfluorinated tertiary alkyl amines
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We wish to report a high-yield synthesis of perfluorinated tertiary amines from their hydrocarbon analogues by direct fluorination. Yields up to 70%, with high purities, have been obtained from certain tertiary amines. This technique will likely develop into a new general method for producing perfluorinated amines.
- Felling, Kyle W.,Lagow, Richard J.
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p. 233 - 236
(2007/10/03)
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- Electrochemical fluorination of 1-ethylpiperazine and 4-methyl- and/or 4-ethylpiperazinyl substituted carboxylic acid methyl esters
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Electrochemical fluorination (ECF) of 1-ethylpiperazine and eight methyl esters of 4-methyl- and/or 4-ethylpiperazinyl substituted carboxylic acids were studied. Corresponding perfluoro(4-fluoro-1-ethylpiperazine) was obtained from 1-ethylpiperazine in a small yield along with perfluoro(1-methyl-3-ethylimidazolidine), perfluoro[2-(N′,N′-difluoroaminoethyl)-N,N-diethylamine)] and perfluorotriethylamine. The corresponding mono-basic perfluoroacid fluorides with a perfluoro(4-alkylpiperazinyl) group were obtained in fair to good yields from the fluorination of methyl esters of 4-alkylpiperazinyl-substituted carboxylic acids. Yields of the targeted perfluoro(4-alkylpiperazinyl) group containing perfluorocarboxylic acid fluorides varied depending on both the type of N-alkyl (alkyl=CH3- or C2H5-) group at the 4-position and the (ω-methoxycarbonylalkyl) group at the 1-position of the piperazine ring of the substrate. Higher yields of perfluoroacid fluorides were obtained by the ECF of 4-ethyl substituted piperazine derivatives than of the 4-methyl substituted piperazine derivatives when 4-alkylpiperazines with the same carboxylic acid ester group were fluorinated electrochemically. Spectroscopic data as well as physical properties are described for new perfluoro(1,4-dialkylpiperazines) and N-containing perfluorocarboxylic acids with a perfluoropiperazinyl group.
- Abe, Takashi,Baba, Hajime,Soloshonok, Irina
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- Electrochemical fluorination of (N,N-dialkylamino)alcohols
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Series of amino alcohols including 2-(N,N-dialkylamino)ethanols, 3-(N,N-dimethylamino)propanol and 4-(N,N-dimethylamino)butanol were subjected to electrochemical fluorination. In the case of 2-(N,N-dialkylamino)ethanols, the F-(2-N,N-dialkylamino)acetyl fluorides were obtained in fair to good yields. Yields of each target compound were strongly dependent on the kind of the dialkylamino group. Cyclic amines having an N-(2-hydroxylethyl) group afforded the corresponding F-[N-(c-alkylamino)-substituted acetyl fluorides]. Their yields were generally better than those of acyclic analogs. Several 2-(N,N-dialkylamino)ethanols and 3-(N,N-dimethylamino)propanol were converted into the corresponding trimethylsilylethers, aminoalkyl methyl carbonates and bis-aminoalkyl carbonate, respectively, and they were subjected to fluorination for a comparison of the yield with that obtained from that of the parent aminoalcohol.
- Abe, Takashi,Fukaya, Haruhiko,Hayashi, Eiji,Ono, Taizo,Nishida, Masakazu,Soloshonok, Irina,Okuhara, Kunio
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p. 229 - 237
(2007/10/03)
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- Technology for the preparation of perfluoro-organic compounds
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Fluorination by elemental fluorine of fluorine-containing alkenes, alkanes, ethers and tertiary amines was investigated, aimed at obtaining the perfluorinated analogs. The factors affecting yield of the target compounds were studied. Elements of technology were elucidated.
- Moldavskii, Dmitrii D.,Bispen, Tatjana A.,Kaurova, Galina I.,Furin, Georgii G.
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p. 157 - 167
(2007/10/03)
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- Mechanistic studies on the electrochemical fluorination of trialkylamines and tetraalkylammonium salts
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The comparative electrochemical fluorination (ECF) of selected trialkylamines and tetraalkylammonium salts was studied in order to obtain experimental data allowing a precise valuation of the ECF mechanism. The results of the investigation favour the ECF mechanism already proposed by Simons, via oxidation of F- .(HF)n to F and nHF, as probably the only relevant electrochemical process at the anode. For the first time some experimental proof has been obtained that a direct electrochemical oxidation of the substrate can be ruled out as a decisive step in ECF.
- Dimitrov,Pfeifer,Jonethal,Ruediger,Seppelt
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p. 143 - 150
(2007/10/03)
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- The electrochemical fluorination of N-containing carboxylic acids (Part 4). Fluorination of methyl 3-dialkylamino-isobutyrates and methyl 3-dialkylamino-n-butyrates
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Several methyl esters of 3-dialkylamino-substituted n- and isobutyric acids have been subjected to electrochemical fluorination to give the corresponding perfluoroacid fluorides.Dimethyl, diethyl, pyrrolidino, morpholino, piperidino and N-methylpiperazino groups were investigated as dialkylamino substituents.The structure/yield relationship was evaluated both in terms of the structure of the acid and the kind of amino group, respectively.Better yields of perfluoroacid fluorides were obtained from methyl esters having isobutyric acid skeletons than those having n-butyric acid groups, and from the acids containing cyclic amino groups than those containing acyclic ones.
- Abe, Takashi,Fukaya, Haruhiko,Hayashi, Eiji,Hayakawa, Yoshio,Nishida, Masakazu,Baba, Hajime
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p. 193 - 202
(2007/10/02)
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- On the electrochemical fluorination of quaternary ammonium compounds. Part 1. Tetraalkyl ammonium salts
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Tetraalkylated ammonium compounds, which are known to be very stable towards oxidative attack, can be electrofluorinated readily to yield perfluoro tertiary amines.Other than the enhanced formation of gaseous cleavage products, the electrofluorination proceeds similarly to that of other tertiary amines.
- Dimitrov. A.,Radeck, W.,Ruediger, St.,Bechstein, O.
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- The electrochemical fluorination of nitrogen-containing carboxylic acids. Fluorination of methyl esters of 3-dialkylamino propionic acids
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Six methyl esters of 3-dialkylamino-substituted propionic acids were subjected to electrochemical fluorination to give the corresponding perfluoroacid fluorides.The following dialkylamino substituents were investigated: diethylamino, di-n-propylamino, di-n-butylamino, pyrrolidino, morpholino and piperidino groups.These perfluoroacid fluorides, which were obtained in fair yields, are considered to be prospective key precursors for preparing soft-type (degradable) fluorochemicals.The salts show a considerable lowering of surface tension in aqueous solution.Thephysical properties of all the perfluoroacid fluorides obtained are reported, together with their spectroscopic data (19F NMR, mass and IR spectra).
- Abe, Takashi,Hayashi, Eiji,Fukaya, Haruhiko,Hayakawa, Yoshio,Baba, Hajime,et al.
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p. 101 - 111
(2007/10/02)
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- THE ELECTROCHEMICAL FLUORINATION OF NITROGEN-CONTAINING CARBOXYLIC ACIDS. FLUORINATION OF DIMETHYLAMINO- OR DIETHYLAMINO-SUBSTITUTED CARBOXYLIC ACID DERIVATIVES
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The electrochemical fluorination of six derivatives of dimethylamino- or diethylamino-substituted carboxylic acids has been conducted.As the main fluorination products, cyclized and cleaved products as well as the desired N-containing perfluoroacid fluorides were formed, and their ratios depended on the chain length and the structure of the starting carboxylic acids, and the nature of the dialkylamino group.Through this work, perfluoro(dimethylamino-acetyl fluoride), perfluoro(diethylamino-acetyl fluoride), perfluoro(2-dimethylamino-propionyl fluoride), perfluoro(2-dimethylamino-butyryl fluoride) and perfluoro(3-dimethylamino-propionyl fluoride) were prepared.Except for perfluoro(dimethylamino-acetyl fluoride), these acid fluorides were new compounds.The physical properties of new compounds obtained including these acid fluorides are reported together with their spectral (19F nmr, Mass and IR) data.
- Abe, Takashi,Hayashi, Eiji,Baba, Hajime,Fukaya, Haruhiko
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p. 257 - 279
(2007/10/02)
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- THE ELECTROCHEMICAL FLUORINATION OF NITROGEN-CONTAINING CARBOXYLIC ACIDS. FLUORINATION OF METHYL ESTERS OF CYCLIC AMINOGROUP SUBSTITUTED CARBOXYLIC ACIDS
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Nine methyl esters of cyclic amino-group substituted carboxylic acids related to glycine, alanine or β-alanine were subjected to electrochemical fluorination.This afforded the corresponding perfluoroacid fluorides together with cleavage products in fair yields.As cyclic amino-substituents, pyrrolidino-, morpholino-, piperidino-, hexamethyleneimino- and N'-methylpiperazinyl-groups were investigated.The formation of cyclized by-products was not observed, which contrasts with the fluorination of aliphatic dialkylamino-substituted carboxylic acids.From such methyl 2-cyclic amino-propionates (cyclic amino-group: a pyrrolidino, a morpholino or a piperidino-group), the perfluorinated methyl esters were obtained together with the corresponding perfluoroacid fluorides in yields of 1-2percent and 14-29percent, respectively.The formation of the former compounds is ascribed to the blocking effect of the bulky cyclic amino-groups.The physical properties of the new compounds obtained are reported together with their spectral (19F NMR, Mass and IR) data.
- Abe, Takashi,Hayashi, Eiji,Fukaya, Haruhiko,Baba, Hajime
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p. 173 - 196
(2007/10/02)
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