359-10-4Relevant articles and documents
An efficient synthesis of 1-chloro-2,2-difluoroethylene via the reductive dechlorination of 1,2,2-trichloro-1,1-difluoroethane
Wang, Nong,Yang, Lijuan,Xiang, Shaoji
, p. 273 - 275 (2013)
1-Chloro-2,2-difluoroethylene was prepared from 1,2,2-trichloro-1,1- difluoroethane by reductive dechlorination in the presence of zero-valent zinc. Eleven different solvents were investigated and the best results were obtained in methanol, dimethyl formamide and ethanol at 80 °C. A large-scale experiment using ethanol as a solvent gave 1-chloro-2,2-difluoroethylene in high yield. These results provide a method for producing 1-chloro-2,2- difluoroethylen e on an industrial scale because 1,2,2-trichloro-1,1- difluoroethane is the waste material arising from 2,2-dichloro-1,1,1- trifluoroethane production. These results can also provide a method for solving the recycling problem of 1,2,2- trichloro-1,1-difluoroethane in 2,2-dichloro-1,1,1-trifluoroethane production.
Infrared Multiphoton Absorption and Reaction of 2-Chloro-1,1,1-trifluoroethane
Setser, D.W.,Lee, Tsae-Shyan,Danen, Wayne C.
, p. 5799 - 5805 (1985)
The infrared multiphoton absorption and dissociation of CF3CH2Cl has been studied by measuring the dependence of the reaction probability and product distribution on the laser fluence and bath gas pressure.Absorption measurements were performed at two laser frequencies to estabilish the absorbed laser energy: the absorption measurements displayed Beer's law behavior except at very low laser fluence.Sensitized reactions with SiF4 were conducted for comparison to the direct laser-induced process: the effective temperature within the irradiated volume for the SiF4 experiments was determined as a function of incident laser energy.The three main reaction channels are four centered HF elimination, three-centered HCl elimination, and C-Cl homolysis: the product ratios were very dependent on the incident laser fluence.Addition of toluene as a bath gas significantly lowered the reaction probability, especially at lower laser fluence, but had only a minor influence on the product distribution.The infrared laser-induced energy absorption and reaction processes of CF3CH3, CF3CH2Cl, and CF3CH2Br are compared.The data provide evidence for a fluence-dependent fractionation of absorbed laser energy producing a two-component energy distribution for the former two compounds.
Characterization by Temperature-Programmed Reduction and by Temperature-Programmed Oxidation (TPR-TPO) of Chromium (III) Oxide-Based Catalysts: Correlation with the Catalytic Activity for Hydrofluoroalkane Synthesis
Brunet, S.,Requieme, B.,Matouba, E.,Barrault, J.,Blanchard, M.
, p. 70 - 74 (1995)
The catalytic activity of chromium (III) oxide for the fluorination of CF3CH2Cl (HCFC 133a) is proportional to the number of reversibly oxidized sites.The proportionality coefficient depends on the atmosphere employed during the pretreatment of the catalyst.The temperature-programmed reduction and temperature-programmed oxidation experiments constitute a simple technique that allows the number of reversibly oxidized chromium atoms to be measured.The method of preparation of the chromium hydroxide has little effect on the catalytic properties of chromium (III) oxide.The activation atmosphere and the temperature are essential parameters in the formation of chromium (III) oxide from hydroxide.Indeed, the most active chromium (III) oxide for the fluorination of CF3CH2Cl is obtained by thermal treatment of hydroxide at 380 deg C under nitrogen.
Vacuum-ultraviolet (147 nm) photodecomposition of 1,1,2-trichloro-2,2-difluoroethane
Yano, T.,Tschuikov-Roux, E.
, p. 3401 - 3409 (1980)
The 147 nm photolysis of CF2ClCHCl2 has been investigated at 25 deg C as a function of reactant pressure, conversion, and nitric oxide as additive.In the absence of NO the observed reaction products are CF2CHCl, CF2CCl2, and the diastereomers of (CF2ClCHCl)2.At constant reactanr pressure the quantum yields of the olefin decrease with increasing conversion and there is a corresponding increase in the quantum yield of the C4 product.For fixed values of conversion the olefin quantum yields decrease with increasing reactant pressure and approach limiting values at ca. 100 Torr.The addition of NO completely suppresses the formation of the chlorofluorobutanes, while it enhances the olefin quantum yields at higher conversion.These observations are interpreted in terms of reactions of chlorine atoms which result either directly (by near simultaneous expulsion of two Cl atoms), or via the dissociation of an excited Cl2* molecule produced by molecular elimination in the primary process.Chlorine atoms abstract hydrogen from the parent or add to the product olefins.These processes provide the principal source of halo-ethyl radicals in the system.The addition reaction leads to chemically activated radicals with a mean lifetime of τ ca. 0.8*10-8 sec which is commensurate with RRKM-theory predictions.The addition of nitric oxide provides a competing channel for chlorine atom removal by way of their NO-catalyzed recombination.The functional dependence of the olefin quantum yields with conversion in the absence and presence of NO suggests that the major fraction of the principal product, CF2CHCl, derives directly from a primary process, while CF2CCl2 is formed via both, the molecular elimination of HCl and from radical precursors.The limiting quantum yields of CF2CHCl and CF2CCl2 are found to be φ0 ca. 0.68 and φ0' ca. 0.19, in the absence of NO, respectively, and φ0,NO ca. 0.56 and φ0,NO' ca. 0.087 in the presence of NO.The extinction coefficient for CF2ClCHCl2 at 147 nm and 25 deg C has been determined: ε = (1/PL)ln(I0/It) = 404 +/- 40 atm-1cm-1.
Photodissociation of 1,1,1-Trifluorodichloroethane at 147 nm. Evidence for Chlorine Atom Reactions
Yano, T.,Jung, K.-H.,Tschuikow-Roux, E.
, p. 2146 - 2151 (1980)
The 147-nm photolysis of CF3CHCl2 has been investigated at 23 deg C as a function of reactant pressure and conversion (It/N), with and without nitric oxide as additive.The principal reaction product is CF2CHF, with lesser yields of CF2CFCl, CF2CHCl, and four chlorofluorobutanes.At constant CF3CHCl2 pressure the observed quantum yields of the olefins decrease with increasing It/N and there is a corresponding increase in the yields of the C4 products.The quantum yields of the olefins also decrease with increasing reactant pressure at the same values of It/N.The addition of NO completely suppresses the formation of the chlorofluorobutanes, but there is a marked increase in the olefin quantum yields.These observations are interpreted in terms of reactions of chlorine atoms which derive, primarily, from the α,α elimination of the elements of (Cl)2 in the primary process.Clorine atoms so produced abstract hydrogen from the parent and add to the product olefins, processes which are the source of haloethyl radicals in the system.Nitric oxide provides an additional and dominant channel for chlorine atom removal by way of their NO-catalyzed recombination which proceeds through CINO as an intermediate.A reaction mechanism consistent with the observations is proposed and, from the functional dependence of the olefin quantum yields on It/N, limiting values have been obtained by extrapolation.The rate constant ratio for hydrogen abstraction from CF3CHCl2 by Cl atoms to Cl addition to CF2CHF was found to be k5/k6 = (2.2 +/- 0.5)*E-4.The extinction coefficient for CF3CHCl2 at 147 nm (296 K) has been determined as ε = (1/PL) ln(I0/It) = 590 +/- 60 atm-1Cm-1.
The room temperature preparation of the 1-chloro-2,2-difluorovinylzinc reagent from HCFC-133a (CF3CH2Cl). The first ambient, high yield, one-flask preparation of α-chloro-β,β-difluorostyrenes
Anilkumar,Burton, Donald J.
, p. 6979 - 6982 (2002)
The reaction of LDA (2.0 equiv.) with a THF solution of ZnCl2 (1.0 equiv.) and HCFC-133a (CF3CH2Cl) (1.0 equiv.) at 15-20°C gives a 91% yield of [F2C=CClZnCl]. Addition of ArI and Pd(PPh3)4 at rt to 65°C gives 65-85% isolated yields of ArCCl=CF2. This one-flask procedure provides the first room temperature generation of the 1-chloro-2,2-difluorovinylzinc reagent and the first high yield preparation of α-chloro-β,β-difluorostyrenes from a cheap, readily available industrial precursor.
Isoflurane increases the anaerobic metabolites of halothane
Rahman,Fujii,Sato,Yuge
, p. 43 - 46 (1994)
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%).
Infrared Multiphoton Dissociation of CClF2CH2Cl by Relatively Low-fluence CO2 Laser Irradiation
Sakka, Tetsuo,Iwasaki, Matae,Ogata, Yukio
, p. 3129 - 3138 (1992)
Infrared multiphoton absorption (IRMPA) and dissociation (IRMPD) of CClF2CH2Cl have been studied by low-fluence CO2 laser irradiation (-2).Laser beams of spatially uniform intensity, obtained by mild focusing and a short irradiation cell length, were used.The IRMPD yields were measured as a function of reactant pressure, added-gas pressure, laser-energy fluence and laser wavenumber, and the IRMPA was measured as a function of reactant pressure, added-rare-gas pressure, and laser-energy fluence.The results of the IRMPD yields plotted against reactant and added-gas pressure show that molecular collisions play an important role in the excitation process.The effects of the reactant pressure and added-rare-gas concentration upon the product yield can be interpreted by a combination of some positive and negative effects of molecular collisions.On the other hand, the dissociation yields obtained as a function of added CF2CHCl pressure suggest that the relaxation of anharmonicity bottlenecking by resonant vibrational energy transfer is also important for IRMPD of this molecule.It can be seen that the other experimental results, i.e. the results of the IRMPA experiments and the frequency dependence of the IRMPD yield are consistent with the above interpretation.
A two-fluorine bromine acetate preparation method (by machine translation)
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Paragraph 0021; 0023, (2019/01/22)
The invention provides a two-fluorine bromine acetate preparation method, comprises the following steps: (1) in order to CF2 X - CHCl2 As raw materials, through the dehydrochlorination cancels out the reaction, bromine addition reaction CF2 Br - CClXBr, wherein X is H or Cl; (2) step (1) in the CF2 Br - CClXBr optical oxidation or with sulfur trioxide oxidation reaction, reaction to obtain the CF2 Br - COCl; (3) the step (2) in the CF2 Br - COCl alcohol in the esterification reaction, after separation, distillation, thus obtaining the product 2, 2 - difluoro - 2 - [...] ester. The invention two fluorine bromine acetate preparation method, so that the 1, 1 - difluoro - 2, 2 - dichloroethane or 1, 1 - difluoro - 1, 2, 2 - trichloroethane two by-product that is utilized, reduce their pollution of the environment, but also the production two fluorine bromines acetate process is environment-friendly, two fluorine bromines acetate yield and safety are relatively high. (by machine translation)
Preparation method of 1,1-difluoro-2-chloroethylene
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Paragraph 0034; 0035; 0036; 0037; 0038; 0039; 0040-0045, (2017/07/19)
The invention discloses a method for preparing 1,1-difluoro-2-chloroethylene by carrying out dehydrochlorination on dichlorodifluoroethane in presence of a catalyst; the catalyst is prepared from a main catalyst-inorganic base and a cocatalyst-phase transfer catalyst. The method provided by the invention does not need to use an organic solvent, and has the advantages of being high in reaction yield, mild in technology, simple in operation, less in by-products, small in amount of the three wastes, environmentally-friendly, and the like.
