- 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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- 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,N',N'-tetramethylethylenediamine
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The electrochemical fluorination of N,N,N',N'-tetramethylethylenediamine was canied out in a modified Simons type cell using anhydrous hydrogen fluoride as a solvent. Effects of various experimental parameters like concentration of amine, temperature, and current density etc. were investigated. In addition to perfluoro-N,N,N',N'-tetramethylethylenediamine, cyclic, cleavage, and partially fluorinated products were obtained and characterized by gas chromatography, IR spectroscopy, nuclear magnetic resonance and mass spectra. A plausible reaction pathway for the electrochemical fluorination of N,N,N',N'-tetramethylethylenediamine has been proposed based on the products obtained. Elsevier Science S.A.
- Sartori,Velayutham,Ignat'ev,Noel
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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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- 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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