- Catalytic fluorination of trichloroethene by anhydrous hydrogen fluoride in the presence of fluorinated chromia under static conditions. Synthesis of [18F]-labelled CF3CH2F and [36Cl]-labelled CF3CH2Cl. Catalytic dehydrofluorination of CF3CH2F and CF3CH2Cl
-
Catalytic fluorination of trichloroethene by anhydrous hydrogen fluoride at 653K in the presence of fluorinated amorphous chromia under static conditions leads to a mixture of products in which partially halogenated olefins predominate. These are converted to mixtures containing CF3CH2F and CF3CH2Cl by a second fluorination using fresh catalyst. The results of product analyses from reactions carried out under various conditions have been used to design a synthesis of [18F]-CF3CH2F from CCl2CHCl. It is proposed that [18F] labelling occurs via direct [18F]- for [19F] exchange rather than by a dehydrofluorination/hydrofluorination route. [36Cl]-labelled CF3CH2Cl is readily prepared from CF3CH2F and H36Cl in the presence of chromia catalysts. Enthalpies of dehydrofluorination of CF3CH2F and CF3CH2Cl in the vapour phase have been computed.Non-SI units employed: ?=10-10m; a.u.≈4.36×10-18 J≈6.27089×102kcalmol-1.1
- Baker, Alan W.,Bonniface, David,Klap?tke, Thomas M.,Nicol, Irene,Scott, John D.,Scott, William D.S.,Spence, Ronald R.,Watson, Michael J.,Webb, Geoffrey,Winfield, John M.
-
-
Read Online
- Synthesis method and application of bis(2, 2, 2-trifluoroethyl) ether
-
The invention provides a synthesis method of bis(2, 2, 2-trifluoroethyl) ether, which comprises the following steps: preparing 1, 1, 1-trifluorodichloroethane, metering and adding 500-550 parts by weight of ethylene glycol, 0.9-1.1 parts by weight of potassium hydroxide and 100 parts by weight of trifluoroethanol into a pressure reaction kettle, sealing the reaction kettle, introducing 110-130 parts by weight of 1, 1, 1-trifluorodichloroethane, stirring and heating to at least 70-80 DEG C, reacting for 2-4 hours, controlling the temperature of the system to be 70-90 DEG C, adding a polar solvent into the system, uniformly stirring, filtering a potassium chloride solid precipitate to obtain a filtrate, rectifying the filtrate to obtain a product with the purity of 99.98% or above, and providing application of the product as a lithium battery electrolyte solution in the field of lithium batteries. The process has the advantages that raw materials are easy to obtain, supply limitation isavoided, equipment requirements are simple, special material requirements are avoided, the process is simple, production requirements are completely met, clean production is achieved, the equipment cost is reduced, the competitive capacity of company products is improved, and economic benefits are improved.
- -
-
Paragraph 0059-0060
(2021/02/10)
-
- METHOD FOR MANUFACTURE OF 1,1,1-TRIFLUORO-2-CHLOROETHANE (HCFC 133A) AND/OR TRFLUOROETHYLAMINE (TFEA)
-
A method for manufacture of 1, 1, 1-trifluoro-2-chloroethane (HCFC-133a) and/or trifluoroethylamine (TFEA), wherein at least one reaction step takes place in a microreactor that is comprising or is made of SiC-microreactor, the processes can be efficiently combined in that HCFC-133a produced by using a microreactor, may preferably advantageously serve as starting material and/or intermediate material in the manufacture of TFEA. The HCFC-133a and/or the TFEA can be easily, by a method with only low energy consumption, purified and/or isolated, and preferably the process for purifying and/or isolating does not require a distillation. Advantageously, the separation from excess hydrogen fluoride (HF) and catalyst can easily take place in an energy-saving manner by phase separation.
- -
-
Page/Page column 27-28
(2020/06/05)
-
- Nature's hydrides: rapid reduction of halocarbons by folate model compounds
-
Halocarbons R-X are reduced to hydrocarbons R-H by folate model compounds under biomimetic conditions. The reactions correspond to a halide-hydride exchange with the methylenetetrahydrofolate (MTHF) models acting as hydride donors. The MTHF models are also functional equivalents of dehalohydrogenases but, unlike these enzymes, do not require a metal cofactor. The reactions suggest that halocarbons have the potential to act as endocrinological disruptors of biochemical pathways involving MTHF. As a case in point, we observe the rapid reaction of the MTHF models with the inhalation anaesthetic halothane. The ready synthetic accessibility of the MTHF models as well as their dehalogenation activity in the presence of air and moisture allow for the remediation of toxic, halogenated hydrocarbons.
- Denk, Michael K.,Milutinovi?, Nicholas S.,Marczenko, Katherine M.,Sadowski, Natalie M.,Paschos, Athanasios
-
p. 1883 - 1887
(2017/03/09)
-
- Compounds and methods for the reduction of halogenated hydrocarbons
-
The present application relates to methods for the reduction of halogenated hydrocarbons using compounds of Formula (I): wherein the reduction of the halogenated compounds is carried out, for example, under ambient conditions without the need for a transition metal containing co-factor. The present application also relates to methods of recovering precious metals using compounds of Formula (I) that are absorbed onto a support material.
- -
-
Page/Page column 19
(2017/12/27)
-
- Insight into "entrainment" in SRN1 reactions of 2,2-dichloro-1,1,1-trifluoroethane(HCFC-123) with thiolates initiated by Na2S2O4
-
An interesting entrainment process in SRN1 reactions of 2,2-dichloro-1,1,1-trifluoroethane (HCFC-123) with thiolates were studied by experiments and DFT calculations. The radical-anion intermediate, generated from coupling of the fluorinated ra
- Tang, Xiao-Jun,Chen, Qing-Yun
-
-
- Unimolecular reactions in the CF3CH2Cl ? CF 2ClCH2F system: Isomerization by interchange of Cl and F atoms
-
The recombination of CF2Cl and CH2F radicals was used to prepare CF2ClCH2F* molecules with 93 ± 2 kcal mol-1 of vibrational energy in a room temperature bath gas. The observed unimolecular reactions in order of relative importance were: (1) 1,2-ClH elimination to give CF2=CHF, (2) isomerization to CF 3CH2Cl by the interchange of F and Cl atoms and (3) 1,2-FH elimination to give E- and Z-CFCl=CHF. Since the isomerization reaction is 12 kcal mol-1 exothermic, the CF3CH2Cl* molecules have 105 kcal mol-1 of internal energy and they can eliminate HF to give CF2=CHCl, decompose by rupture of the C-Cl bond, or isomerize back to CF2ClCH2F. These data, which provide experimental rate constants, are combined with previously published results for chemically activated CF3CH2Cl* formed by the recombination of CF3 and CH2Cl radicals to provide a comprehensive view of the CF3CH2Cl* ? CF 2ClCH2F* unimolecular reaction system. The experimental rate constants are matched to calculated statistical rate constants to assign threshold energies for the observed reactions. The models for the molecules and transition states needed for the rate constant calculations were obtained from electronic structures calculated from density functional theory. The previously proposed explanation for the formation of CF2=CHF in thermal and infrared multiphoton excitation studies of CF3CH 2Cl, which was 2,2-HCl elimination from CF3CH 2Cl followed by migration of the F atom in CF3CH, should be replaced by the Cl/F interchange reaction followed by a conventional 1,2-ClH elimination from CF2ClCH2F. The unimolecular reactions are augmented by free-radical chemistry initiated by reactions of Cl and F atoms in the thermal decomposition of CF3CH2Cl and CF 2ClCH2F.
- Enstice, Erin C.,Duncan, Juliana R.,Setser,Holmes, Bert E.
-
experimental part
p. 1054 - 1062
(2011/04/18)
-
- Catalytic process for the preparation of fluorinated halocarbons
-
A process is described for the preparation of 2-chloro-1,1,1-difluoroethane by the reaction of 1,2-dichloro-1,1-difluoroethane with hydrogen fluoride. in the presence of a fluorination catalyst. The process utilizes a rate enhancing reagent that is trichloroethylene, is 1-fluoro-1,2,3-trichloroethane or an aromatic rate enhancing reagent having the formula where R is C1 to C6 linear or branched alkyl substituted with at least one halo group, halo or nitro and R′ is C1 to C6 linear or branched alkyl substituted with at least one halo group.
- -
-
Page/Page column 1-3
(2009/01/24)
-
- Process for the preparation of fluorinated halocarbons
-
A improved process is described for the preparation of a substantially pure, liquefied stream of 1,1,1,2-tetrafluoroethane by the catalyzed reaction of trichloroethylene with hydrogen fluoride to form the intermediate 2-chloro-1,1,1-trifluoroethane and then reacting said intermediate 2-chloro-1,1,1-trifluoroethane with hydrogen fluoride, in the presence of a hydrofluorination catalyst to form a reaction stream containing 1,1,1,2-tetrafluoroethane. The improvement comprises liquefying the by-product hydrogen chloride formed in the preparation of the intermediate 2-chloro-1,1,1-trifluoroethane and countercurrently passing said liquefied hydrogen chloride thru the reaction stream containing 1,1,1,2-tetrafluoroethane thereby forming a substantially pure, liquefied stream of 1,1,1,2-tetrafluoroethane and an effluent comprising gaseous hydrogen chloride.
- -
-
Page/Page column 4
(2008/12/07)
-
- Solvent effects in the fluorination of 1,2-dichloro-1,1-difluoroethane (R-132b) to 2-chloro-1,1,1-trifluoroethane (R-133a)
-
Trichloroethylene has been found to act as a rate enhancing co-factor in the liquid phase, tantalum (V) halide catalyzed, fluorine-for-chlorine exchange reaction of 1,2-dichloro-1,1-difluoroethane (R-132b) to 2-chloro-1,1,1-trifluorethane (R-133a). Several trifluoromethyl substituted benzenes have also been found to be rate-enhancing solvents.
- Belter, Randolph K.,Bhamare, Nanaji K.
-
p. 1606 - 1610
(2008/09/18)
-
- PROCESS FOR THE PRODUCTION OF 1,1,1,3,3,3-HEXAFLUOROPROPANE
-
A process for the preparation of 1,1,1,3,3,3-hexafluoropropane is disclosed. The process involves (a) contacting at least one halopropane of the formula CF3CH2CHyX3-y (where each X is independently F, Cl or Br, and y is 3, 2, or 1) with Cl?2#191 in the presence of light or a free radical initiator to produce a mixture comprising CF3CH2CCIyX3-y; (b) contacting the CF3CH2CCIyX3-y produced in step (a) with HF, optionally in the presence of a fluorination catalyst, to produce a product mixture comprising CF3CH2CF3; and (c) recovering CF3CH2CF3 from the mixture produced in step (b).
- -
-
Page/Page column 14
(2008/06/13)
-
- METHOD FOR PRODUCTION OF FLUOROALYKYLFLUOROALKANE-SULFONATE
-
PROBLEM TO BE SOLVED: To provide a method for simply producing, under more moderate condition than heretofore, a fluoroalkylfluoroalkane-sulfonate useful as an intermediate for medicines or agrochemicals and as a reagent for introducing a fluorine-containing group. SOLUTION: The fluoroalkyl fluoroalkane-sulfonate is produced by reacting a perfluoroalkanesulfonyl halide with a fluorine-containing alcohol in the presence of a base. In this case, an organic solvent is not used but water coexists as a solvent. It is particularly preferable that a reaction temperature is ≥-10°C but ≤40°C and water content is ≥0.2 g and ≤5 g per 1 g of the fluorine-containing alcohol. According to this method, for example, 2,2,2-trifluoroethyltrifluoromethane-sulfonate or 2,2,3,3-tetrafluoropropyltrifluoromethane-sulfonate can efficiently be produced, and the discharge amount of waste materials can remarkably be reduced. COPYRIGHT: (C)2006,JPOandNCIPI
- -
-
Page/Page column 11; 13
(2008/06/13)
-
- PROCESS FOR PRODUCTION OF 1,1,1,2-TETRAFLUOROETHANE AND/OR PENTAFLUOROETHANE AND APPLICATIONS OF THE SAME
-
A process for producing high purity 1,1,1,2-tetrafluoroethane and/or pentafluoroethane by the step of purifying a crude product obtained by reacting trichloroethylene and/or tetrachloroethylene with hydrogen fluoride comprised of a main product including 1,1,1,2-tetrafluoroethane and/or pentafluoroethane, hydrogen fluoride as an azeotropic component with the main product, and impurity ingredients including at least an unsaturated compound, wherein said purifying step includes a step of bringing a mixture obtained by newly adding hydrogen fluoride into said crude product into contact with a fluorination catalyst in the vapor phase to reducing the content of the unsaturated compound contained in said crude product and a distillation step.
- -
-
Page/Page column 10-16
(2008/06/13)
-
- PROCESS FOR THE PREPARATION OF 1,1,1,2,2-PENTAFLUOROETHANE
-
A process for the preparation of pentafluoroethane is disclosed which involves contacting a mixture comprising hydrogen fluoride and at least one one starting material selected from haloethanes of the formula CX3191CHX2 and haloethenes of the formula CX2=CX2, where each X is independently selected from the group consisting of F and Cl (provided that no more than four of X are F), with a fluorination catalyst in a reaction zone to produce a product mixture comprising HF, HCl, pentafluoroethane, underfluorinated halogenated hydrocarbon intermediates and less than 0.2 mole percent chloropentafluoroethane based on the total moles of halogenated hydrocarbons in the product mixture. The process is characterized by the fluorination catalyst comprising (i) a crystalline cobalt-substituted alpha-chromium oxide where from about 0.05 atom % to about 6 atom % of the chromium atoms in the alpha-chromium oxide lattice are replaced by trivalent cobalt (Co+3) and/or (ii) a fluorinated crystalline oxide of (i).
- -
-
-
- Method for purifying tetrachloroethylene and process for producing hydrofluorocarbons
-
Tetrachloroethylene containing a stabilizer is contacted with a zeolite having an average pore size of 3.4 to 11 ? and/or a carbonaceous adsorbent having an average pore size of 3.4 to 11 ? in a liquid phase to obtain a high purity tetrachloroethylene. A halogenated alkene and/or a halogenated alkane are reacted with hydrogen fluoride in the presence of a fluorination catalyst to produce a first hydrofluorocarbon, a halogenated alkene and/or a halogenated alkane are reacted with hydrogen fluoride in the presence of a fluorination catalyst to produce a second hydrofluorocarbon, and the products are joined and then distilled to obtain the first and second hydrofluorocarbons.
- -
-
Page/Page column 7-10
(2008/06/13)
-
- Reaction pathways of 2,2,2-trifluoroethylamine and n-butylamine with [Ru(bpy)2(NO)Cl]2+
-
The reaction of [Ru(bpy)2(NO)Cl]2+ with 2,2,2-trifluoroethylamine produced [Ru(bpy)2(NO)Cl]+ by electron transfer and a number of organic compounds formed via nucleophilic substitution of the intermediate 2,2,2-trifluoroethyldiazonium ion (free or coordinated). Density functional theory computed results suggest that stabilization of the trifluoroethyldiazonium ion by complexation is much larger than the one corresponding to the butyl ion, in agreement with the fact that no rearrangement products derived from CF3CH2+ were observed.
- Di Salvo, Florencia,Crespo, Alejandro,Estrin, Darío A.,Doctorovich, Fabio
-
p. 4237 - 4244
(2007/10/03)
-
- A study of trichloroethylene hydrofluorination using a kinetic model
-
The kinetic features of catalytic hydrofluorination of trichloroethylene and 2-chloro-1,1,1-trifluoroethane on chromium fluoride/magnesium fluoride catalyst were studied. The effect of pressure and addition of various components of the reaction mixture at the reactor inlet was studied using the developed model.
- Dmitriev,Trukshin,Smykalov
-
p. 771 - 776
(2007/10/03)
-
- Turnover Rate, Reaction Order, and Elementary Steps for the Hydrodechlorination of Chlorofluorocarbon Compounds on Palladium Catalysts
-
The rates of hydrodechlorination catalyzed by Pd supported on carbon for four chlorofluorocarbons spanned a range of 7 orders of magnitude. The rates scaled up to the bond strength of the carbon-chlorine bond for the gas-phase reactant. This finding demonstrates that the rate-determining step involves the scission of the C-Cl bond and suggests, through Polanyi and linear free-energy relationships, that rates for other compounds can be estimated if the C-Cl bond strength is known. The reaction orders for the most abundant products are approximately first-order for the chlorine-containing compound, half-order in H2, and inverse first-order in HCl. The reaction steps consistent with these orders include a rate-determining step involving the adsorption of the chlorofluorocarbon to a single site (which could be a single surface palladium atom) and equilibrated steps between gas-phase H2, gas-phase HCl, and adsorbed hydrogen and chlorine atoms. The rates on the supported catalysts are comparable to the ones reported before on a Pd foil, indicating that the support does not play a role in the reaction. The product distribution is independent of conversion, implying that the various products are formed from a single visit of the reactant on the surface and not from readsorption of gas-phase products. The four compounds studied were chloropentafluoroethane (CF3-CF2Cl), 2-chloro-1,1,1,2-tetrafluoroethane (CF3-CFClH), 1,1-dichlorotetrafluoroethane (CF3-CFCl2), and 1,1,1-trichloro-2,2,2-trifluoroethane (CF3-CCl3).
- Thompson,Rioux,Chen,Ribeiro
-
p. 3067 - 3077
(2007/10/03)
-
- Generation of radical species in surface reactions of chlorohydrocarbons and chlorocarbons with fluorinated gallium(III) oxide or indium(III) oxide
-
The reactions of C1 and C2 chlorohydrocarbons and chlorocarbons have been studied with the Lewis acid catalysts fluorinated gallium(III) oxide and fluorinated indium(III) oxide, respectively. Product analysis shows chlorine-for-fluorine exchange reactions together with the formation of 2-methylpropane and its chlorinated analogues 2-chloromethyl-1,3-dichloropropane and 2-chloromethyl-1,2,3-trichloropropane. Reactivities of the chlorohydrocarbon probe molecules show fluorinated gallium(III) oxide to be a stronger Lewis acid than fluorinated indium(III) oxide. The formation of the symmetrical butyl compounds is consistent with the generation of surface radical species and is also consistent with a 1,2-migration mechanism operating within radical moieties at the Lewis acid surface.
- Thomson
-
p. 1881 - 1885
(2007/10/03)
-
- Process for fluorinating halogenated hydrocarbon
-
An object is to effectively preparing a fluorinated compound by developing a catalyst which is effective in the fluorination of a halogenated alkane or alkene with hydrogen fluoride by a gas phase fluorination or addition of hydrogen fluoride. To this end, a catalyst which comprises a least one element selected from the group consisting of Ti, V, Zr, Mo, Ge, Sn and Pb, and alumina, aluminum fluoride or partially fluorinated alumina is used. This catalyst is prepared by an impregnation method to support the above element on alumina and the like, or a precipitation method in which the catalyst is co-precipitated from a solution containing an aluminum compound and a compound of the above element.
- -
-
-
- Catalytic synthesis of 1,1,1,2-tetrafluoroethane from 1,1,1,2-tetrachloroethane - A mechanistic consideration
-
1,1,1,2-Tetrachloroethane and its fluorinated derivatives as well as trichloroethene are fluorinated by hydrogen fluoride in the presence of a pre-conditioned chromia catalyst. The reaction pathways are derived under different conditions. Fluorinated haloalkanes are formed both by dehydrochlorination/hydrofruorination mechanism as well as chlorine/ fluorine exchange mechanism. Thus, beside fluorinated alkanes considerable amounts of haloolefins occur in the product mixture. A survey is given on the reaction pathway showing dependence on the reaction conditions. It is discussed with respect to calculated thermodynamic data. Kinetic and mechanistic investigations of the isomerisation reactions of 1.1.2.2-tetrafluoroethane on a CFC-conditioned chromia catalyst are also presented. The desired 1.1.1.2- tetrafluoroethane can be obtained from its symmetric isomer in the presence of a chromia catalyst conditioned exclusively with chlorine-free fluorocarbons. Mechanistic information is obtained by employing DCl which behaves similar to HF during the consecutive isomerisation reaction of 1.1.2.2- tetrafluoroethane. Thus, it is most probable that dehydrohalogenation/hydrohalogenation processes (elimination/addition mechanism) are mainly responsible for the formation of the haloolefins and halocarbons observed on chromia.
- Kemnitz,Niedersen,Kohne
-
p. 485 - 493
(2007/10/03)
-
- Mechanistic aspects of the isomerization reactions of 1,1,2,2-tetrafluoroethane on a CFC-conditioned chromia catalyst
-
The mechanism of the isomerization reactions of 1,1,2,2-tetrafluoroethane on a CFC-conditioned chromia catalyst was investigated. The desired 1,1,1,2-tetrafluoroethane can be obtained from its symmetric isomer in the presence of a chromia catalyst conditioned exclusively with chlorine-free fluorocarbons. In the presence of chlorofluorocarbons, hydrogen chloride is formed as a result of the decomposition reactions of the haloalkane used and is strongly adsorbed on to the surface. This HCl causes a very complex system of side-reactions. In addition, a second kind of chlorine, inactive chloride bonded to chromium, is formed which can only be removed as the result of a very slow solid-gas reaction. Mechanistic information was obtained by examining the effects of substituting DCl for HCl as the chlorine source for the reaction with consecutive isomerization products of 1,1,2,2-tetrafluoroethane. Thus, it is most probable that dehydrohalogenation/hydrohalogenation processes (elimination/addition mechanism) are mainly responsible for the formation of the halo-olefins and halocarbons observed on chromia. As the HCl/DCl adsorbed on the surface is very quickly removed by the reactions with the halocarbons and halo-olefins, it is advantageous to employ pulse techniques to evaluate this reaction system.
- Kemnitz,Niedersen
-
p. 111 - 119
(2007/10/03)
-
- Liquid phase fluorination process and fluorinated organic products resulting therefrom
-
In an improved process and plant for carrying out liquid phase fluorination in the presence of a catalyst, consisting in reacting hydrofluoric acid and an organic starting material in a reaction zone, and in separating, in a separating zone, reactional mixture and at least one light fraction containing the desired fluorinated organic products and at least a first part of the sub-fluorinated organic products formed, and a heavy fraction that includes the remainder of the sub-fluorinated organic products formed, and further comprising partial condensation of the said light fraction in order to obtain a gaseous phase containing the desired fluorinated organic products and a liquid phase containing said first part of the said sub-fluorinated organic products, said heavy fraction being returned to said reaction zone and said liquid phase being returned as a reflux to the top of the separation zone, intermediate recovery is carried out at, or in the proximity of, the lower portion of said separation zone.
- -
-
-
- Heterogeneous catalyzed synthesis of 1,1,1,2-tetrafluoroethane from 1,1,1,2-tetrachloroethane - thermodynamics and reaction pathways
-
1,1,1,2-Tetrachloroethane and its fluorinated derivatives, as well as trichloroethene, were fluorinated by hydrogen fluoride in the presence of a preconditioned chromia catalyst.The reaction pathways were derived under different conditions.Fluorinated haloalkanes are formed both by dehydrochlorination/hydrofluorination mechanisms as well as a chlorine/fluorine exchange mechanism.Thus, beside fluorinated alkanes considerable amounts of halo-olefins occur in the product mixture.A survey is given of the reaction pathways showing their dependence on the reaction conditions.These are discussed with respect to the calculated thermodynamic data. - Keywords: Heterogenous catalysis; Chlorofluorocarbon; Hydrofluorocarbon; Halocarbon; Fluorination; HFC-134a formation
- Kohne, A.,Kemnitz, E.
-
p. 103 - 110
(2007/10/03)
-
- Selective hydrogenolysis of CFC-113a by Group VIII transition metal complexes
-
Highly efficient and selective hydrogenolysis of CFC-113a (CF3CCl3) to produce HCFC-123 (CF3CHCl2) has been achieved through the use of Group VIII transition metal complexes.The catalytic activity observed was sensitive to solvents and to the structure of the metal complexes. - Keywords: Selective hydrogenolysis; CFC-113a; Group VIII transition metal complexes; Catalysis; Selectivity
- Cho, Ook-Jae,Lee, Ik-Mo,Park, Kun-You,Kim, Hoon-Sik
-
p. 107 - 110
(2007/10/02)
-
- Synthetic utility of HCFC-123 (2,2-dichloro-1,1,1-trifluoroethane): the reaction between HCFC-123 and aldehydes using zinc
-
HCFC-123 (2,2-dichloro-1,1,1-trifluoroethane) reacted with zinc and aldehydes to afford predominantly either 1-substituted 2-chloro-3,3-difluoro-2-propen-1-ols or 1-substituted 2,2-dichloro-3,3,3-trifluoro-1-propanols.The reactions proceeded via 1,1-dichloro-2,2,2-trifluoroethylzinc chloride as an organozinc intermediate. - Keywords: 2,2-Dichloro-1,1,1-trifluoroethane; Reaction; Aldehydes; Zinc; 1,1-Dichloro-2,2,2-trifluoroethylzinc chloride
- Tamura, Masanori,Sekiya, Akira
-
p. 119 - 122
(2007/10/02)
-
- INVESTIGATIONS IN THE REGION OF INDUSTRIAL FLUORINATED COMPOUNDS
-
The synthesis and properties of ozone-friendly fluorohydrocarbons, fluoroolefins, and fluorinated compounds with functional groups (acids, alcohols, esters, and others), used for the creation of effective surfactants, ion-exchange membranes for various purposes, heat-resistant oils, and greases, were investigated.A technology was developed for the production of highly pure fluorinated compounds for microelectronics, fiber optics, and medicine.
- Maksimov, B. N.
-
p. 1935 - 1940
(2007/10/03)
-
- Stabilisation of Palladium Metal Function of Oxide Supported Palladium Catalyst during the Hydrogenolysis of Chlorofluorocarbons
-
Relative to Pd/C or Pd/γ-Al2O3 systems, γ-alumina supported Pd/ZnO catalyst enhanced catalytic activity and stability towards deactivation by halogen adsorption, during the hydrogenolysis of 1,1,2-trichlorotrifluoroethane.
- Sweetman, M. J.,Thomson, J.
-
p. 2385 - 2386
(2007/10/02)
-
- Isoflurane increases the anaerobic metabolites of halothane
-
The effect of isoflurane on the anaerobic metabolism of halothane to chlorodifluoroethene (CDE) and chlorotrifluoroethane (CTE) was studied with microsomes of guinea pig liver by gas chromatography. The reaction mixture used to measure the end products of anaerobic metabolism consisted of a microsomal suspension, 3 mM NADPH, halothane and isoflurane (except in control groups) in 0.1 M potassium phosphate buffer solution (pH 7.4). The K(m) values for CDE formation were 601.61 ± 266.91, 254.22 ± 86.58, 257.92 ± 129.11, 268.55 ± 125.66 and 319.22 ± 86.76 μM (mean ± SD, n = 5) at 0 mM (0%), 0.12 mM (0.26%), 0.29 mM (0.64%), 0.58 mM (1.30%) and 1.16 mM (2.59%) isoflurane, respectively. The K(m) values for CTE formation were 1204.74 ± 551.64, 553.75 ± 177.89, 521.14 ± 249.77, 560.67 ± 229.61 and 711.05 ± 317.13 pM (n = 5) at 0 mM (0%), 0.12 mM (0.26%), 0.29 mM (0.64%), 0.58 mM (1.30%) and 1.16 mM (2.59%) isoflurane, respectively. In contrast, the V(max) values for CDE and CTE formation at these isoflurane concentrations were not significantly different than in the control groups. In this study the production of CDE and CTE was significantly (P 0.05) increased by isoflurane, at concentrations up to 0.58 mM (1.30%).
- Rahman,Fujii,Sato,Yuge
-
-
- Deuterium isotope studies of the hydrofluorination of chloroethenes over chromia catalysts
-
The mechanism of the catalytic fluorination of chloroalkenes over a chromia catalyst has been investigated by examining the effects of substituting DF for HF as the fluorine source for reaction with tetrachloroethene and trichloroethene.At a temperature of 250 degC and a HF (DF)/alkene molar ratio of 4.2:1, the rate of conversion of tetrachloroethene is increased by using DF and there is a concomitant increase in the selectivity to some chlorofluoroalkanes and a decrease in the selectivity to chlorofluoroalkenes.The opposite behaviour observed for the halogenated alkenes and alkanes indicates that the alkenes are not important intermediates in the production of the alkanes by a series of hydrofluorination and dehydrochlorination reactions.For tetrachloroethene, the main reaction pathway to the alkanes is a direct chlorine/fluorine exchange over a heavily fluorinated chromia surface with minimal C-H/C-D cleavage of intermediates.Substitution of DF for HF causes no change in the product selectivities from reaction with trichloroethene over chromia catalysts.However, the presence of dideutero - and monodeutero - products shows that both chlorine/fluorine exchange and HF addition / HCl elimination pathways are occurring for the less-substituted alkene.
- Kavanagh, David M. C.,Ryan, T. Anthony,Mile, Brynmor
-
p. 167 - 176
(2007/10/02)
-
- A Method for Synthesis of Fluorine Compounds Using Abnormal Grignard Reaction of Halothane
-
The reaction of 2-bromo-2-chloro-1,1,1-trifluoroethane (1) with 2-octanone (3a) in the presence of magnesium did not give 2-chloro-1,1,1-trifluoro-3-methyl-3-nonanol (4a) but 2-bromo-2-chloro-1,1,1-trifluoro-3-methyl-3-nonanol (5a) and 2-chloro-1,1-difluoro-3-methyl-1-nonen-3-ol (6a).This suggested that the primary Grignard reagent, 1-chloro-2,2,2-trifluoroethylmagnesium bromide (2), reacted with excess 1 rather than with the ketone 3a to give 1-bromo-1-chloro-2,2,2-trifluoroethylmagnesium bromide (8), which added to the ketone to give 5a.Detection of 1,1,1-trifluoro-2-chloroethane supported this mechanism.Compound 5a was formed preferentially at -53 deg C, and as the reaction mixture was warmed to 0 deg C, the amount of 5a decreased, while that of 6a increased.Therefore, compound 6a must be formed by reduction of 5a with excess magnesium.Treatment of 6a with hydrogen fluoride gave 2-chloro-1,1,1-trifluoro-3-methyl-2-nonene (9a).Cyclohexanone and acetophenone reacted similarly to give corresponding products.
- Takagi, Toshiyuki,Takesue, Atsushi,Koyama, Mayumi,Ando, Akira,Miki, Takuichi,Kumadaki, Itsumaro
-
p. 3921 - 3923
(2007/10/02)
-
- Method of preparing fluorine-containing ethane derivatives
-
A method of preparing fluorine-containing ethane derivatives using a catalyst mixture which comprises a metal halide and a sulfonic acid derivative is described. The method is particularly well suited for preparing CF3 CHCl2 (R123) from perchloroethylene and for preparing CF3 CH2 F (R134a) from trifluoroethylene.
- -
-
-
- Process for the purification of 1,1,1,2-tetrafluoroethane
-
A method for reducing the 1-chloro-2,2-difluoroethylene content of a mixture thereof with 1,1,1,2-tetrafluoroethane comprising heating the mixture with hydrogen fluoride in the liquid phase at a temperature in the range 50-180°C and in the substantial absence of a fluorination catalyst. The mixture which is heated may be the product stream obtained by reaction of hydrogen fluoride with trichloroethylene and/or 1-chloro-2,2,2-trifluoroethane.
- -
-
-
- Reduction of polyhalofluoroalkanes with formate to hydrogen-bearing alternatives initiated by carbon dioxide anionic radical
-
Reduction of polyhalofluoroalkanes with formate in the presence of a catalytic amount of persulfate is described.Such a reagent posseses good selectivity in the reduction of carbon-chlorine bonds.A chain mechanism including carbon dioxide anionic radicals and polyhalofluoroalkyl radicals is proposed.
- Hu, Chang-Ming,Tu, Ming-Hu
-
p. 105 - 108
(2007/10/02)
-
- Catalytic hydrogen-transfer reduction of polyhalofluoroalkanes using sodium hypophosphite
-
The catalytic hydrogen-transfer reduction of polyhalofluoroalkanes using sodium hypophosphite in the presence of a platinum or palladium catalyst is described.A selective reduction of carbon-bromine bonds could be performed under mild conditions.
- Hu, Chang-Ming,Tu, Ming-Hu
-
p. 101 - 104
(2007/10/02)
-
- Unimolecular Rate Constants for Chemically Activated 1,1,1-Trifluoro-2-chloroethane: A Competitive Three-Channel System
-
Chemically activated CF3CH2Cl was prepared with 97.5 kcal/mol of internal energy by the combination of CF3 and CH2Cl radicals.The total unimolecular decomposition rate constant was measured by using two internal standard methods and the average was (7.5 +/- 2.61.5) * 106 s-1.The rate constant for four-centered elimination of HF was measured as (2.8 +/- 0.1) * 106 s-1, for C-Cl bond homolysis the rate constant was (0.8 +/- 5.60.1) * 106 s-1, and by difference the three-centered HCl elimination rate constant was (3.9 +/- 2.63.0) * 106 s-1.These rate constants were compared to predictions from RRKM theory, and threshold energies were assigned for loss of HF (76 kcal/mol), for C-Cl-bond rupture (83 kcal/mol), and for HCl elimination (72 kcal/mol).Product distributions from three activation methods (chemical, multiphoton laser, and thermal) were analyzed to develop a self-consistent view of this complex reaction system.
- Rakestraw, David, J.,Holmes, Bert E.
-
p. 3968 - 3975
(2007/10/02)
-
- LASER-POWERED HOMOGENEOUS DECOMPOSITION OF 1-BROMO-1-CHLORO-2,2,2-TRIFLUOROETHANE
-
CW CO2 photosensitized (SF6) homogeneous decomposition of 1-bromo-1-chloro-2,2,2-trifluoroethane yields various halobutenes and haloethanes.The former are suggested to arise from a sequence of C-Br cleavage, radical recombinations to halobutanes and conse
- Pola, Josef,Chvatal, Zdenek
-
p. 233 - 244
(2007/10/02)
-
- Electron Transfer Reactions in Organic Chemistry. XIV. The Reactivities of Some Polyhaloalkanes toward the Outer-Sphere Electron Transfer Reductants Co(II)sepulchrate2+ and Co(II)W12O407-
-
Rates were measured for the title reactions in CH3CN/H2O buffered at pH ca.7 at 20 or 50 deg C.The following order of reactivity toward Co(II)W12O407- was found: CBr4 > (CBrCl2)2 > CBr2Cl2 > C2Cl6 > CBrCl3 > CF3CHClBr > CHBr3 > CCl4.Only CBr4, (CBrCl2)2, CBr2Cl2 and CBrCl3 gave measurable rates of reaction with Co(II)sepulchrate2+, and with the same order of reactivity as above.Four these four substrates, a plot of log kET2+ had a slope close to 1.Qualitative product studies for the reactions with Co(II)W12O407- showed that the polyhalomethanes generally reacted by losing their heaviest halogen, while polyhaloethanes formed ethylenes by losing their havies halogen on each carbon atom.For some of the reactions, the intermediate radical formed in the first step could be trapped by N-t-butyl-α-phenylnitrone.The resulting spin adducts were detected by ESR spectroscopy.It is agrued that the rate constant difference between CBr4 and CBrCl3 supports the notion of a very short-lived intermediate anion radical.
- Eberson, Lennart,Ekstroem, Mikael
-
p. 113 - 121
(2007/10/02)
-
- One-electron Reduction of Halothane (2-Bromo-2-chloro-1,1,1-trifluoroethane) by Free Radicals. Radiation Chemical Model System for Reductive Metabolism
-
The reaction mechanism of one-electron and radical-induced degradation of the general anaesthetic halothane (2-bromo-2-chloro-1,1,1-trifluoroethane) has been investigated for γ-irradiated, oxygen-free aqueous solutions containing various alcohols or formate.Modern ion chromatography and conventional g.c.-m.s. methods were used as analytical tools for identification of end products.This includes quantitative determination of Cl- ions in the presence of Br- ions.Reduction of halothane by hydrated electrons, various alcohol radicals, and .CO2- proceeds via Br- elimination and CF3.CHCl radical formation as initial step. t-Butyl alcohol radicals .CH2C(CH3)2OH abstract bromine atoms to yield BrCH2C(CH3)2OH which suffers base-catalysed Br- elimination.Chain reactions leading to high Br- yields are observed in sulutions containing propan-2-ol, ethanol, methanol and formate.Based on 2k = 1E9 mol-1 dm3 s-1 for the dimerization of 2 CF3.CHCl radicals the following rate constants have been measured: k(CF3.CHCl + propan-2-ol) = 670 mol-1 dm3 s-1, k(CF3.CHCl + ethanol) = 130 mol-1 dm3 s-1, k(CF3.CHCl + metanol) = 27 mol-1 dm3 s-1 and k(CF3.CHCl + formate) = 2900 mol-1 dm3 s-1.Dimerization of CF3.CHCl leads to CF3CHClCHClCF3 which suffers base-catalysed HCl elimination to yield the two stereoisomers of CF3CH=CClCF3.The halothane results are compared with corresponding findings in CCl4-containing systems.
- Moenig, Joerg,Asmus, Klaus-Dieter
-
p. 2057 - 2063
(2007/10/02)
-
- Comparison of the Reactivity of CF3OX (X = Cl, F) with Some Simple Alkenes
-
Reactions of CF3OX (X = Cl, F) with a variety of simple alkenes were carried out to compare the regio- and stereoselectivity of the additions to carbon-carbon double bonds.The observed addition products with CF3OCl are consistent with an electrophilic syn addition.With CF3OF the observed products indicate a different regioselectivity and low stereoselectivity, consistent with a free-radical addition.
- Johri, Kamalesh K.,DesMarteau, Darryl D.
-
p. 242 - 250
(2007/10/02)
-