- Fluorination of organic compounds with cobalt trifluoride and elemental fluorine in the presence of cobalt trifluoride
-
Fluorination of organic compounds with cobalt trifluoride and elemental fluorine in the presence of cobalt trifluoride was studied. Fluorination with elemental fluorine proceeds under external-kinetic control at a constant rate. Examples of fluorination w
- Moldavskii,Furin,Shkul'tetskaya,Eifman
-
-
Read Online
- Electrochemical fluorination of unsaturated sulfides and sulfones
-
Electrochemical fluorination of some unsaturated sulfides and sulfones and their reactions with anhydrous HF were studied.
- Grigor'eva,Shainyan,Kaurova,Gracheva,Lesnevskaya,Barabanov
-
p. 1095 - 1100
(2007/10/03)
-
- Improvements in or relating to contrast agents
-
Combined preparations comprising an injectable gas dispersion and a coadministrable diffusible component which is capable of inward diffusion into the dispersed gas so as to promote temporary growth of the gas in vivo, the preparations being for use as contrast agents in ultrasound cardiac studies of patients who have undergone physical exercise-induced stress in order to promote vasodilatation.
- -
-
-
- Electrochemical fluorination of hexahydroazepine, methylpiperidines and methyl 1-hexahydroazepine-acetate: The preparation of F-(1-hexahydroazepine-acetyl fluoride) and its derivatives
-
The electrochemical fluorination of hexahydroazepine (1), methylpiperidines (2) [2-methylpiperidine (2a), 3-methylpiperidine (2b), 4-methylpiperidine (2c)] and methyl 1-hexahydroazepine-acetate (3) was examined. An extensive cleavage of the C-N bond occurred in the fluorination of secondary cyclic amines (1, 2a-c) resulting in only a small yield of the corresponding F-(N-fluoro cyclic amines). F-(1-hexahydroazepine-acetyl fluoride) (4) was obtained in a fair yield from the fluorination of 3 along with F-[(methylpiperidino)-acetylfluoride] which was formed as a result of the isomerization of 3 during fluorination. In addition, several derivatives of 4 were synthesized. F-(1-iodomethyl-hexahydroazepine) (4a) was prepared by the reaction of 4 with anhydrous LiI. The compound 4 was converted into its potassium salt (4c) via methyl F-(1-hexahydroazepine-acetate) (4b), which upon pyrolysis in the presence or absence of ethylene glycol resulted in the formation of 1-difluoromethyl-dodecafluoro(hexahydroazepine) (4d) and F-(3,4,5,6-tetrahydroazepine) (4e), respectively. F-(1-hexahydroazepine-acetoamide) (4f), F-(1-hexahydroazepine-acetonitrile) (4g) and corresponding p-methoxyanilide (4h) were also derived from 4.
- Abe, Takashi,Pandey, Sushil K.,Baba, Hajime
-
p. 149 - 157
(2007/10/03)
-
- Technology for the preparation of perfluoro-organic compounds
-
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.
-
p. 157 - 167
(2007/10/03)
-
- Electrochemical fluorination of (N,N-dialkylamino)alcohols
-
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
-
p. 229 - 237
(2007/10/03)
-
- Investigations on the product distribution pattern during the electrochemical fluorination of 2-fluoropyridine and pyridine
-
By using 2-fluoropyridine instead of pyridine as the starting material, a 19% conversion yield of perfluoropiperidine was obtained during the electrochemical fluorination process. At least ten products including perfluoropiperidine were characterised using repeated fractional distillation followed by GC and NMR analysis.
- Sartori,Velayutham,Ignat'ev,Noel
-
-
- Production of perfluorinated organic compounds
-
Fluorination of a series of perfluoroolefins and their alkoxy and diethylamino derivatives with elemental fluorine in the gas and liquid phases was studied. The possibility of fluorinating these compounds with pure fluorine was demonstrated. The fluorination parameters were determined, and separate stages of processes for preparing a series of practically important products were developed. The heats of fluorination of the compounds studied were calculated.
- Bispen,Moldavskii,Furin
-
p. 1409 - 1417
(2007/10/03)
-
- The electrochemical fluorination of N-containing carboxylic acids (Part 4). Fluorination of methyl 3-dialkylamino-isobutyrates and methyl 3-dialkylamino-n-butyrates
-
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
-
p. 193 - 202
(2007/10/02)
-
- LASER-INDUCED DECOMPOSITION OF HEPTAFLUORO-2-IODOPROPANE
-
CO2 laser-induced homogeneous decomposition of i-C3F7I yields a variety of perfluorinated compounds, which are suggested to be formed by recombinations of carbenes and radicals generated upon the cleavage of the C-1 bond and the fragmentation of the i-C3F7 radical.The decomposition of i-C3F7I in the presence of ethene leads mainly to the formation of (i-C3F7CH2)2 and i-C3F7(CH2)2I.
- Pola, Josef,Horak, Milan
-
p. 121 - 124
(2007/10/02)
-
- The electrochemical fluorination of nitrogen-containing carboxylic acids. Fluorination of methyl esters of 3-dialkylamino propionic acids
-
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.
-
p. 101 - 111
(2007/10/02)
-
- Synthesis of Functional Perfluorinated Resins, Branched Perfluorinated Ethers and Perfluoroalkanoyl Fluorides
-
Functional-group-containing perfluorinated resins have been prepared by carefully controlled direct fluorination of poly-(3-methyloxetane-3-methanol).Branched perfluorinated ethers such as bis(perfluoroneopentyl) ether and perfluoro-(2,2-dimethylbutyl methyl ether) have also been synthesized by direct fluorination of alkanols.The by-products, perfluoroalkanoyl fluorides, are useful intermediates.
- Huang, Hsu-Nan,Lagow, Richard J.
-
p. 871 - 875
(2007/10/02)
-
- THE ELECTROCHEMICAL FLUORINATION OF NITROGEN-CONTAINING CARBOXYLIC ACIDS. FLUORINATION OF METHYL ESTERS OF CYCLIC AMINOGROUP SUBSTITUTED CARBOXYLIC ACIDS
-
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
-
p. 173 - 196
(2007/10/02)
-
- Synthesis of Unusual Perfluorocarbon Ethers and Amines Containing Bulky Fluorocarbon Groups: New Biomedical Materials
-
The reactions of elemental fluorine with structually crowded hydrocarbon ethers and amines have been studied.The perfluorinated products are currently of interest in biomedical or electronic industrial applications.The syntheses by direct fluorination of perfluoro(tert-butyl methyl ether), perfluoro(tert-butyl isobutyl ether), perfluoro(1,2-di-tert-butoxyethane), perfluoro(cyclohexyl neopentyl ether), perfluoro(2,2,5,5-tetramethyltetrahydrofuran), perfluoro(2,5-dimethyltetrahydrofuran), bis(perfluoroisopropyl) ether, perfluoro(2-ethyltetrahydrofuran), and perfluoro(1,2,2,6,6-pentamethylpiperidine) are reported.The skeletally rearranged byproducts perfluoro(isobutyl methyl ether), perfluoro(2,2,5-trimethyltetrahydrofuran), perfluoro(2,2,5-trimethyltetrahydropyran), 3-hydropentadecafluoro-2,2,5,5-tetramethyltetrahydrofuran, perfluoro(isopropyl propylether), and perfluoro(ethyl isopropyl ether) were also characterized.The 19F and 13C (19F decoupled) NMR assignments of these perfluorinated chemicals are discussed.
- Huang, Hsu-Nan,Persico, Daniel F.,Lagow, Richard J.,Clark, Leland C.
-
-
- 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)
-
- Aerosol Direct Fluorination: Alkyl Halides. 2. Chlorine Shift and the Stability of Radicals
-
Unlike alkyl bromides and iodides, alkyl chlorides are shown to be stable to direct fluorination, even under ultraviolett irradiation, at temperatures of 30 deg C and below.Although less reactive than the bromides and iodides, F-alkyl chlorides may be derivatized, presenting another example of direct fluorination-survivable functionality.High (63 percent) to moderate (32 percent) isolated yields of the analogous perfluororalkyl chlorides can be synthesized by aerosol direct fluorination of 1-chloropropane, 1-chlorobutane, 1-chloro-2-methylpropane, 1-chloro-3-methylbutane, 1-chlo-ro-2-methylbutane, and chlorocyclopentane with generally less than 20 percent C-C bond cleavage.Tertiary alkyl chlorides generally undergo intramolecular 1,2-chloride shift in the earliest stages of reaction in a manner characteristic of β-chloro radicals forming principally primary F-alkyl chlorides.Thus 2-chloro-2-methylpropane produces 1-chloro-F-2-methylpropane (47 percent), and 2-chloro-2-methylbutane produces a 16:6.3:1 ratio of 1-chloro-F-2-methylbutane, 1-chloro-F-3-methylbutane, and 2-chloro-F-3-methylbutane, respectively, in 32 percent combined yield.Secondary alkyl chlorides undergo a similar but incomplete rearrangement producing mixtures of primary and secondary F-alkyl chlorides.Thus 2-chloropropane produces a 2:1 mixture of 2-chloro-F-propane and 1-chloro-F-propane in 50 percent combined yield; 2-chlorobutane produces a 1:1.5 mixture of 2-chloro-F-butane and 1-chloro-F-butane in 34 percent combined yield, and 3-chloropentane produces a 2:3:1 mixture of 3-chloro-F-pentane, 2-chloro-F-pentane, and 1-chloro-F-pentane, respectively, in a combined yield of 30 percent.Because secondary alkyl chlorides partially rearrange but primary alkyl chlorides donot rearrange at all on fluorination, doubt is cast on the postulate that the intermediate radicals are equilibrating.
- Adcock, James L.,Evans, William D.
-
p. 2719 - 2723
(2007/10/02)
-
- ELECTROCHEMICAL FLUORINATION OF N-CHLOROALKYL-SUBSTITUTED CYCLIC AMINES
-
The electrochemical fluorination of such N-chloroalkyl substituted cyclic amines as N-chloromethylpyrrolidine (1), N-(3-chloropropyl)pyrrolidine (2), N-chloromethylpiperidine (3), N-(2-chloroethyl)piperidine (4), N-(3-chloropropyl)piperidine (5), N-chloromethylmorpholine (6), N-(3-chloropropyl)morpholine (7), N-(2-chloroallyl)morpholine (8) has been conducted.Except in the cases of the N-chloromethyl-substituted ones (1,3 and 6), the corresponding chlorine-retaining-perfluoroamines were obteined in a yield of 5 - 20 percent together with perfluorinated ones (Yield = 20 - 60 percent).Neither chlorine-retaining amines nor perfluorinated amines, both of which having the original skeleton, was produced from fluorinations of 1, 3 and 6 in an appreciable yield.The spectroscopic data and physical properties of newly synthesized perfluoro-N-chloroalkyl-substituted cyclic amines are presented.
- Hayashi, Eiji,Abe, Takashi,Baba, Hajime,Nagase, Shunji
-
p. 371 - 382
(2007/10/02)
-
- POLYFLUORO-1,2-EPOXY-ALKANES AND - CYCLOALKANES. PART II. REACTIONS OF DECAFLUORO-1,2-EPOXYCYCLOHEXANE
-
The epoxy ring of the title compound has been opened by nucleophilic attack using lithium aluminium hydride, sodium methoxide, methyl lithium, sodium azide and potasssium cyanide.The primary product incorporated the nucleophile (N) and an alkoxy function, which was fixed by methylation when N=CN.However, in most cases the alkoxide group decomposed to carbonyl, and the ketone was isolated when N was OMe.More nucleophile could be added across this carbonyl group, the resultant substituted alkoxide being isolated as the tertiary alcohol (N=Me) or the methyl ether (N=N3).With lithium aluminium hydride (N=H), a secondary alcohol was obtained, the fluorine on the ring carbon bearing the alkoxy group being replaced by H; the pathway probably did not involve a free carbonyl group, since the resultant alcohol was a pure stereoisomer.This was shown by nmr, and also since the pure methoxymethyl ether made from it was dehydrofluorinated exclusively to 2H-octafluorocyclohexenyl methoxymethyl ether.
- Coe, Paul L.,Mott, Andrew W.,Tatlow, John Colin
-
p. 659 - 668
(2007/10/02)
-
- GAS PHASE RADIATION CHEMISTRY OF HEXAFLUOROETHANE
-
The Co-60 gamma radiolysis of gaseous C2F6 was investigated at 50 Torr pressure, both pure and with 10percent oxygen added.For the pure system, the radiolytic products and their respective G values were CF4, 2.27; C3F8, 0.23; C4F10, 0.09; C5F12, 0.015; and C6F14, 0.009.All radiolysis products except for CF4 (C = 0.61) were eliminated when 10percent O2 was added as scavenger.The results are discussed mainly in terms of the decomposition of excited C2F6 into free radicals, which can then combine.The unscavenged CF4 is accounted for by the ion-molecule reaction CF3+ + C2F6 -> CF4 + C2F5+.
- Scanlon, Michael D.,Hanrahan, Robert J.
-
p. 199 - 208
(2007/10/02)
-
