- Transformations of dichloromethane radicals in alkaline water solutions
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Among transformation products of CHCl2 and CH 2Cl radicals generated by γ-irradiation of deaerated water solutions of dichloromethane oxygen-containing compounds (formic acid, formaldehyde, carbon monoxide) and chloride ions were found. The radicals CHCl2 suffer nucleophilic substitution by hydroxyl ions affording anion-radicals HCOO-2 that further transform into formic acid. At the growing concentration of alkali the frequency of chlorine substitution with hydroxyl ions in the dichloromethane radicals increases, and their transformation process becomes a chain reaction.
- Kosobutskii,Vrublevskii
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- Tunneling dynamics and spatial correlations of long chain growth in solid-state photochlorination of ethylene at low temperatures
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A novel method is described for preparing reactive cryocrystals by deposition of argon-diluted reactant beams and subsequent crystallization during evaporation of the inert gas.Photochlorination of equimolecular ethylene-chlorine mixtures obtained by this method and studied by means of kinetic UV- and IR-spectroscopy reveals activationless chain growth with mean length 300 units in the temperature range 17-45 K.Mean chain lengths greater than 100 are observed up to the conversion degree of 0.6-0.7.Comparison of the experimental data with computer simulations shows that the tunneling reaction is due to the formation of a closely packed reaction complex with high amplitudes of zero-point vibrations which lower the reaction barrier.The commensurability of reactant and product crystal lattices results in linear propagation of chains without accumulation of deformation strain.The chain termination mechanism associated with the spatial correlations of chains is discussed.
- Misochko, E. Ya.,Wight, C. A.,Vetoshkin, E. V.,Benderskii, V. A.
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- Abstraction Reactions of Methylene with Deuterated Methyl Halides
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Tritiated methylene from the 3130-Angstroem photolysis of ketene-t has been reacted with unscavenged deuterated methyl halides (CD3X with X=F, Cl, Br, I) in the gas phase.The distribution of tritium among the products indicates that the reaction of CHT with CD3X often proceeds by halogen abstraction (X=Cl, Br, I) to form CHTX and CD3.The fractional yields of the radioactive products from recombination of such radicals are too large to originate solely from 3CHT reactions, and they imply therefore that most or all of this reaction must be initiated by singlet methylene, as in the following reaction: 1CHT + CD3X --> CHTX + CD3.No halogen abstraction is observed from ketene-t photolysis in the presence of CD3F.The tritiated ethylenes formed in these systems have been analyzed for deuterium content and show measurable quantities of C2H2DT, C2HD2T, and C2D3T.The monodeuterio compound C2H2DT cannot be formed from a direct methylene/ methyl halide reaction, but instead requires a methylene / methyl reaction such as the following : 3CH2 + CHDT --> CH2CHDT* - H --> CH2=CDT.THe 3CH2 (and 3CHT) radicals must react very slowly with CD3X in order to survive for milliseconds without chemical reaction.
- Lee, Peter S.-T.,Rowland, F. S.
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- Kinetics of the reactions of chlorine atoms with C2H4 (k1) and C2H2 (k2): A determination of ΔHf,298° for C2H3
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The rate constant (k1) for the reaction of Cl atoms with C2H4 has been measured as a function of pressure (0.2-100 Torr) at 297 K using the relative rate technique in two reactors with either FTIR or GC analysis. The results of these and previous experiments (100-3000 Torr) can be described to within ±10% by a Tree expression with the limiting rate constants k1(∞) = (3.2 ± 0.15) × 10-10 cm3 molecule-1 s-1; and k1(0) = (1.42 ± 0.05) × 10-29 cm6 molecule-2 s-1 using Fcent = 0.6. The stated uncertainties are statistical only, and the true uncertainties in the limiting rate constants must include uncertainty in Fcent. Temperature-dependent (297-383 K) measurements of k1 were carried out in the low-pressure regime (0.2-2 Torr) yielding the rate constant expression k1(0) = (1.7 ± 0.3) × 10-29(T/298)-3.28 cm3 molecule-1 s-1. The rate constant, k1b, for the abstraction channel of reaction 1 to form the vinyl radical was determined at 300, 343, and 383 K. This measurement of k1b in combination with literature values of k-1b allows a determination of the heat of formation of the vinyl radical by the third law method [ΔHf,298o(C2H3) = 70.6 ± 0.4 kcal/mol]. Using the same data with the second law yields ΔHf,298o(C2H3) = 69.6 ± 1.6 kcal/mol. These measurements agree satisfactorily with a recent negative-ion photoelectron spectroscopy determination of this quantity (71.6 ± 0.8 kcal mol-1). The pressure dependence of the rate constant (k2) for the reaction of Cl with C2H2 was determined over the range 0.3-700 Torr. The results of these and previous experiments (100-6000 Torr) can be described to within ±10% by a Troe expression with the limiting rate constants k2(∞) = (2.0 ± 0.1) × 10-10 cm3 molecule-1 s-1 and k1(0) = (6.1 ± 0.2) × 10-30 cm6 molecule-2 s-1 using Fcent = 0.6.
- Kaiser,Wallington
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- Onium Ylide Chemistry. 4. Alkylhalonium Methylides
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Alkylhalonium methylides were generated by two independent routes, proving their formation through derived product analysis.The reaction of singlet methylene, produced by photolysis of diazomethane, with methyl and ethyl halides gives in competition with C-H insertion evidence of methylenation of halogen atom, i.e., alkylhalonium methylide formation.The unstable halonium methylides are immediatly protonated or alkylated in the reaction medium to give dialkylhalonium ions which then undergo cleavage to the corresponding alkyl halides.Methyliodonium methylide was also generated via the deprotonation of dimethyliodonium hexafluoroantimonate with sodium hydride in competition with the expected methylation of fluoride and hydride, giving the major products.Subsequent methylation of the methyliodonium methylide by excess dimethyliodonium ion gives methylethyliodonium ion followed by cleavage leading to the formation of ethyl halides and via hydride reduction to ethane, respectively.Attempted formation of alkylhalonium methylides via fluoride cleavage of methylhalonium hexafluoroantimonates was unsuccessful due to ready disproportionation of the halonium ions.
- Olah, George A.,Doggweiler, Hans,Felberg, Jeff D.
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- A systematic study on the activation of simple polyethers by MoCl 5 and WCl6
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MoCl5, 1a, and WCl6, 1b, activate 1,3-dioxolane at room temperature in chlorinated solvents: the compound [MoOCl 3{OC(H)OCH2CH2Cl}]2, 2, has been isolated from MoCl5/dioxolane. The mixed oxo-chloro species WOCl 4, 1c, reacts with 1,3-dioxolane, selectively giving the coordination adduct WOCl4(κ1-C3H6O 2), 3. Dimethoxymethane, CH2(OMe)2, undergoes activation including C-H bond cleavage when reacted with 1a to give the molybdenum complexes [MoOCl3{OC(H)OMe}]2, 4, and Mo 2Cl5(OMe)5, 5. The reactions of 1b with CH 2(OR)2 (R = Me, Et) proceed via O-abstraction with formation of the oxo-derivatives WOCl4[O(R)CH2Cl] (R = Me, 6a; R = Et, 6b) in admixture with equimolar amounts of RCl. The reactions of 1a,b with CMe2(OMe)2 lead to mesityl oxide, MeC(O)CHC(Me)2. A series of simple diethers of general formula ROCH2(CHR′)OR′′ are activated by 1a,b in CDCl 3, usually via cleavage of C-O bonds at high temperature. The complex WCl5(OCH2CH2OMe), 7, has been detected in solution as an intermediate species in the course of the degradation of 1,2-dimethoxyethane (dme) by 1b. The activation of CH(OMe)3 by 1 is limited to C-O bonds and selectively gives methyl chloride and methylformate, which has been found coordinated in WOCl4[OC(H)OMe], 8. The organic fragments produced in the reactions have been detected by GC-MS and NMR analyses, upon hydrolysis of the reaction mixtures. Compounds 2 and 5, which have had their molecular structures ascertained by X-ray diffraction, represent rare examples of crystallographically-characterized dinuclear Mo(v) species containing both halides and oxygen ligands.
- Dolci, Sara,Marchetti, Fabio,Pampaloni, Guido,Zacchini, Stefano
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- NUCLEOPHILIC DISPLACEMENT REACTIONS AT Se(II). REACTION OF ARENESELENENYL CHLORIDES AND 2-CHLOROALKYL PHENYL SELENIDES
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The products of the title reaction depend upon the relative concentrations of reactants.With equimolar concentrations or an excess of 2-chloroalkyl phenyl selenide, the products are 1,2-dichloroethane and a diaryldiselenide.When excess areneselenenyl chloride is used, the products are a diaryl diselenide and 2-chloroalkyl phenyl selenide dichloride.A mechanism involving nucleophilic displacement at selenenyl selenium is proposed to account for the observed products.Structural changes in the selenide on varying substituents in the 4-position of areneselenenyl chloride has little effect on the rate of the reaction.In the proposed continuum of mechanisms of nucleophilic displacement reactions at Se(II), an SN2-like transition state best accounts for the data.
- Schmid, George H.,Garratt, Dennis G.
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- Nitrogen-Doped Carbon-Assisted One-pot Tandem Reaction for Vinyl Chloride Production via Ethylene Oxychlorination
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A bifunctional catalyst comprising CuCl2/Al2O3 and nitrogen-doped carbon was developed for an efficient one-pot ethylene oxychlorination process to produce vinyl chloride monomer (VCM) up to 76 % yield at 250 °C and under ambient pressure, which is higher than the conventional industrial two-step process (≈50 %) in a single pass. In the second bed, active sites containing N-functional groups on the metal-free N-doped carbon catalyzed both ethylene oxychlorination and ethylene dichloride (EDC) dehydrochlorination under the mild conditions. Benefitting from the bifunctionality of the N-doped carbon, VCM formation was intensified by the surface Cl*-looping of EDC dehydrochlorination and ethylene oxychlorination. Both reactions were enhanced by in situ consumption of surface Cl* by oxychlorination, in which Cl* was generated by EDC dehydrochlorination. This work offers a promising alternative pathway to VCM production via ethylene oxychlorination at mild conditions through a single pass reactor.
- Chen, De,Chen, Qingjun,Fuglerud, Terje,Ma, Guoyan,Ma, Hongfei,Qi, Yanying,Rout, Kumar R.,Wang, Yalan
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- Thermal degradation of bis (2-chloroethyl) sulfide (mustard gas)
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The thermal degradation of mustard gas (ClCH2CH2SCH2CH2Cl, HD ), with and without 5% added water, is examined. GC/MS, LC/MS and NMR were employed to comprehensively analyze the products. After 75 days at 90°C, 91% HD remains (80% with 5% water). After 40 days at 140°C, 30% HD remains (24% with 5% water) and black tar precipitates form. The apparent Ea is 22.4 kcal/mol. Major products include Q (ClCH2CH2SCH2CH2SCH2CH2Cl), 1,2-dichloroethane, polysulfides and 1,4-dithiane. With 5% water, oxygenates such as 1,4-thioxane and 2-chloroethanol are produced as are numerous sulfonium ions, including S-(2-chlorethyl)-1,4-dithianium, a major component of mustard heels. The decomposition does not go to completion due to the equilibrium nature of the reaction at these temperatures.
- Wagner, George W.,Maciver, Brian K.,Rohrbaugh, Dennis K.,Yang, Yu-Chu
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- Partial oxidation of light alkanes by periodate and chloride salts
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The efficient and selective partial oxidation of light alkanes using potassium periodate and potassium chloride is reported. Yields of methane functionalization in trifluoroacetic acid reach >40% with high selectivity for methyl trifluoroacetate. Periodat
- Kalman, Steven E.,Munz, Dominik,Fortman, George C.,Boaz, Nicholas C.,Groves, John T.,Gunnoe, T. Brent
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- Influence of Silver Addition on the Catalytic Behavior of Cobalt
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A variety of experimental techniques including flow reactor studies, temperature-programmed oxidation, and transmission electron microscopy have been used to investigate the manner by which silver modifies the catalytic behavior of cobalt.For this purpose the growth of filamentous carbon along with the gas phase product distribution resulting from the decomposition of ethylene over cobalt and cobalt-silver particles at 600 deg C has been used as a probe reaction.It was found that the incorporation of as little as 1percent of silver into cobalt caused a increase of over an order of magnitude in the amount of carbon filaments produced compared to that formed on pure cobalt under the same experimental conditions.It is suggested that some of the observed enhancement in catalytic activity could be due to the existence of electronic perturbations of cobalt induced by the presence of silver that are manifested in modifications in the adsorption and subsequent decomposition characteristics of ethylene on the bimetallic surface.Analysis of the gas phase effluent reveals that ethane is the major product with minor amounts of methane.This distribution indicates that on the cobal-silver surface there is a strong tendency for ethylene to absorb in a direction parallel to the surface and either is hydrogenated to ethane or undergoes carbon-carbon bond scission with resulting carbon species dissolving and diffusing through the catalyst particle to form the filamentous carbon deposit.This behavior is to be contrasted with that found for the cobalt-copper/ethylene system where a significant amount of methane is produced and believed to originate from the decomposition of an ethylidyne intermediate arising from adsorption of the olefin on the bimetallic surface in an "end-on" configuration.
- Chambers, Alan,Rodriguez, Nelly M.,Baker, R. Terry K.
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- Ultraviolet Absorption Spectra of the CH2Cl and CHCl2 Radicals and the Kinetics of their Self-recombination Reactions from 273 to 686 K
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The UV absorption spectra of the chloromethyl (CH2Cl) and dichloromethyl (CHCl2) radicals have been determined between 197.5 and 230 nm, together with the absolute rate constants for their association reactions: CH2Cl + CH2Cl -> products (1a), CHCl2 + CHCl2 -> products (1b) as a function of temperature from 273 to 686 K and between 29 and 760 Torr N2 total pressure.The transient decays of the radicals were monitored by time-resolved UV absorption following the flash photolysis of Cl2 mixed with the parent molecules (CH3Cl or CH2Cl2).At a resolution of 2 nm, no vibrational structure was detected in either spectrum which both appear as strong broad electronic bands with maxima around 200 nm (CH2Cl) and 215 nm (CHCl2).At these wavelengths the absolute absorption cross-sections were measured as (1.45 +/- 0.16) x 10-17 and (1.34 +/- 0.24) x 10-17 cm2 molecule-1, respectively, relative to that of CH3O2 at 240 nm (4.55 x 10-18 cm2 molecule-1).The experimental results, supported by RRKM calculations, demonstrate that the measured rate constants for removal of the radicals correspond to the high-pressure limiting rate constants for recombination, both of which exhibit a negative temperature dependence, represented by the following expressions: CH2Cl: k1a = (2.8 +/- 0.3) x 10-11 (T/298)-(0.85 +/- 0.14) cm3 molecule-1 s-1.CHCl2: k1b = (9.3 +/- 1.7) x 10-12 (T/298)-(0.74 +/- 0.10) cm3 molecule-1 s-1.Errors are 1?.The present results are compared to existing data on the self-recombination reactions of the CH3 and CCl3 radicals; the negative temperature dependence of the self-association rate constants for the series CH3, CH2Cl, CHCl2 and CCl3 are shown to be consistent within the framework of a recently developed variational transition-state theory method.
- Roussel, Pascal B.,Lightfoot, Philip D.,Caralp, Francoise,Catoire, Valery,Lesclaux, Robert,Forst, Wendell
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- Reactions of N-Pentafluorosulfanylurethanes and Thiolurethanes with Phosphorus Pentachloride
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Urethanes of the type SF5NHC(O)OR react with PCl5 to give primarily SF5NCO.In only one case, where R = C6H5, was any evidence for an imine product observed.The corresponding reactions of SF5NHC(O)SR compounds give both SF5NCO and the imine product.The new compounds SF5N=C(Cl)SCH3 and SF5N=C(Cl)SC6H5 were identified by IR, NMR, and mass spectrometry.
- Thrasher, Joseph S.,Clifford, Alan F.
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- Gas-Phase Reactions of Atomic Chlorine with Vinyl Chloride
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The reactions of chlorine atoms with CH2=CHCl have been investigated over the pressure range from 70 to 4000 torr by using radioactive (38)Cl atoms formed by neutron irradiation of CClF3.The only observed product when CH2=CHCl is the sole substrate is CH2=CH(38)Cl in yields varying from 1.35percent at 4000 torr to 44.2percent at 71-torr total pressure.With HI present as a second substrate, CH2ClCH2(38)Cl is observed as a major product with a yield as high as 78percent at 4000-torr total pressure, and CH3CHCl(38)Cl is also found in yields of 2percent or less.A 1,2-chlorine atom migration is required in the overall mechanism, and two quite different kinetic schemes fit the observed yields of CH2=CH(38)Cl and CH2ClCH2(38)Cl very satisfactorily.The favored mechanism involves little initial preference for addition to the CH2 or CHCl ends of CH2=CHCl.The yields of CH2ClCH2(38)Cl at high pressures are proceded by a 1,2-chlorine atom migration from collisionally stabilized CH2CHCl(38)Cl radicals to form CH2(38)ClCHCl or CH2ClCH(38)Cl prior to abstraction of H from HI to form CH2ClCH2(38)Cl.The absolute reaction rate for (38)Cl with CH2=CHCl has been estimated from its relative rate vs. reaction with HI to be about 1.5 X 10E-10 cm3 molecule-1s-1.The energy barriers for chlorine atom addition to either end of CH2=CHCl are no larger than a few hundred cal/mol, and the loss of chlorine atoms from excited CH2(38)ClCHCl* or CH2CHCl(38)Cl* radicals must also have barriers in the exit channels no larger than a few hundred cal/mol.
- Iyer, R. Subramonia,Rowland, F. S.
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- From 1,2-dialkoxyalkanes to 1,4-dioxanes. A transformation mediated by NbCl5via multiple C-O bond cleavage at room temperature
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The formation of 1,4-dioxanes and alkyl chlorides from the reactions of polyethers (dme, diglyme, 1,2-diethoxyethane, 1,2-dimethoxypropane) with NbCl5 at room temperature is described; as far as dme is concerned, the reaction mainly occurs in two steps, consisting of (i) cleavage of one O-CH3 bond, followed by (ii) cleavage of the second O-CH3 bond and one of the two O-CH2 linkages. The characterization of intermediate complexes and the isolation of NbOCl3(dme) are reported. The Royal Society of Chemistry.
- Marchetti, Fabio,Pampaloni, Guido,Zacchini, Stefano
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- Adsorption and Conductivity Studies in Oxychlorination Catalysis. Part 3.-The Ethene - Transition-metal Chloride Interaction
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Gas adsorption chromatography (g.a.c.) has been used to obtain isotherms and isosteric heats of adsorption of C2H4 at temperatures 2 ratio.G.a.c. studies of C2H4 on PdCl2, PtCl2 and PtCl4 indicate that chemical reaction occurs at room temperature.For those adsorbents for which heats of adsorption had been obtained, further reaction was initiated by increasing the temperature above 150 deg C.Reaction products, e.g.HCl, vinyl chloride, dichloroethane and polymers, were identified, where possible, by mass spectrometry or chromatography.The capabilities of a microreactor to study the copper chloride - C2H4 system have been evaluated.
- Hall, Peter G.,Heaton, Philip,Rosseinsky, David R.
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- Laser-Initiated Chain Reactions and Microexplosions in Solid Solutions of Simple Alkenes and Chlorine
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Solid-state photochlorination reactions of ethene and propene have been initiated by pulsed ultraviolet laser photolysis.Quantum yields and product branching ratios have been determined by Fourier transform infrared spectroscopy.At 48 K, the photochemical quantum yield for the ethene/Cl2 system is 116 +/- 15.The reaction forms predominantly the anti conformer of 1,2-dichloroethane.At 50K, the propene/Cl2 system yields the largest quantum yields reported to date in the solid state, 740 +/- 120; the anti conformer of 1,2-dichloropropane is the predominant product in this case.At 10K, the reactions of both systems are characterized by a sudden burst of reactivity (a microexplosion) after exposure to a cumulative laser fluence of only 0.9 mJ/cm2 at 337 nm.As much as 67percent of the reactants are converted to products during the microexplosion.A new technique has been developed which utilizes microexplosions for determining relative IR band intensities for conformational isomers in the solid state.
- Tague, Thomas J.,Kligmann, Peter M.,Collier, C. Patrick,Ovchinnikov, Mikhail A.,Wight, Charles A.
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- Single-stage oxychlorination of ethanol to ethylene dichloride using a dual-catalyst bed
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The direct production of ethylene dichloride, EDC, from ethanol over a dual-catalyst bed consisting of a zeolite pre-bed and a CuCl2-NaCl/ γ-Al2O3 oxychlorination catalyst has been shown to give greater than 80% yield of EDC with ethyl chloride as the main by-product. The effects of temperature, HCl/air ratio and space velocity were investigated. The most effective zeolite was ZSM-5. It is concluded that the main route to EDC was via ethyl chloride and its oxychlorination and disproportionation.
- Al-Hajri, Rashid,Chadwick, David
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- Photochlorination of Chloroethane and Chloroethane-d5
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The hydrogen/deuterium abstraction from C2H5Cl and C2D5Cl by ground-state chlorine atoms has been investigated between 8 and 94 deg C.Results from the internal competition in chloroethane and chloroethane-d5 combined with the results of external competition with CH4 as the reference reaction have yielded rate constant data for the following reactions: CH3CH2Cl + Cl -> CH3CHCl + HCl, k2s; CH3CH2Cl + Cl -> CH2CH2Cl + HCl, k2p; CD3CD2Cl + Cl -> CD3CDCl + DCl, k2s,D; CD3CDCl + Cl -> CD2CD2Cl + DCl, k2p,D.The temperature dependence of the rate constants (cm3s-1) is given by k2s = (1.43 +/- 0.29) X 1E-11 exp, k2p = (1.35 +/- 0.28) X 1E-11 exp, k2s,D = (0.72 +/- 0.14) X 1E-11 exp , and k2p,D = (0.60 +/- 0.12) X 1E-11 exp.The results confirm the general trend of chlorine atom attack being faster at the substituted carbon atom.Kinetic isotope effects for the abstraction of primary and secondary hydrogen are kH/kD = 5.8 and 2.0 at 298 K, respectively.The magnitude of these relatively weak isotope effects agrees with expectations based on other exothermic chlorination reactions and suggests that in the temperature range of the investigation tunneling does not play an important role.
- Tschuikow-Roux, E.,Yano, T.,Niedzielski, J.
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- Preparation of high quality ethephon using domestic diester bis-(2-chloroethyl)-2-chloroethylphosphonate as substrate
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Ethephon has been widely used globally. However, few companies can manufacture high quality ethephon with content of 90% in China mainland. This work described a practical procedure, which utilizing bis-(2-chloroethyl)-2- chloroethylphosphonate 2 produced by local Chinese companies as substrate to prepare ethephon with content of over 90 % and high yield.
- Zhang, Wenlong,Sun, Dequn
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- The reactivity of well defined diiron(III) peroxo complexes toward substrates: Addition to electrophiles and hydrocarbon oxidation
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The reactivity of previously reported peroxo adducts [Fe(μ-O2)(μ-L)(O2CPhCy)2(1-Bu-Im)2] (1), and [Fe(μ-O2)(μ-L)(O2CPhCy)2(py)2] (2), where L is a dinucleating ligand based on the m-xylylenediamine bis(Kemp's triacid imide), toward a variety of substrates is described. These studies were performed to probe the electronic properties of 1 and 2 and evaluate their potential as selective hydrocarbon oxidants. Compound 1 is nucleophilic at -77°C, reacting with phenols and carboxylic acids to liberate hydrogen peroxide, whereas the less electron-rich pyridine analogue 2 is unreactive toward both reagents. By contrast, neither reacts at -77°C with electrophilic reagents such as olefins or triphenylphosphine, or with weak hydrogen atom donors such as dimethylbenzylamine. When solutions of 1 are warmed to room temperature in solvents such as THF, toluene, and cyclopentane, mixtures of alcohol and ketone products derived from the solvent are formed. A detailed investigation of cyclopentane oxidation strongly points to a radical autoxidation pathway. These results are discussed in the context of the selective hydroxylation chemistry that occurs at the carboxylate-bridged diiron centers in soluble methane monooxygenase. Copyright (C) 1999 Elsevier Science Ltd.
- LeCloux, Daniel D.,Barrios, Amy M.,Lippard, Stephen J.
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- Application of Time-Resolved Infrared Spectroscopy to the Determination of Absolute Rate Constants for Cl + C2H6 and Cl + C2H5Cl
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Time-resolved infrared spectroscopy (TRISP) has been used to determine at 700 Torr and 298 K the absolute rate constants of reactions (1) Cl + C2H6 = C2H5 + HCl 1 = 7.05 (+/-1.4)*10-11 cm3/molecule s> and (2) Cl + C2H5Cl = C2H4Cl + HCl 2 = 6.8 (+/-1.4)*10-12 cm3/molecule s>.Pulsed UV laser photolysis of Cl2 in flowing mixtures of Cl2, C2H6 (or C2H5Cl), and air initiated the reaction.Absolute rate constants were measured by observing the rate of HCl production using this pulsed, broad-band IR technique for time delays from 50 ns to 10 μs after the photolysis laser pulse.Because chain propagation occurs via reactions (4) C2H5 + Cl2 = C2H5Cl + Cl or (6) C2H4Cl + Cl2 = C2H4Cl2 + Cl, corrections for these reactions were included in the absolute rate calculations.A determination of the rate constant of reaction 6 relative to reaction 5, C2H4Cl + O2 = C2H4ClO2, was required to calculate k2.The ratio k6/k5 was measured at 700 Torr by continuous UV photolysis of Cl2, O2, and C2H5Cl mixtures in a static reactor using the relative rate technique.Values of k6/k5 = 0.42 (+/-0.06) and 0.63 (+/-0.15) were obtained for 1-chloroethyl and 2-chloroethyl radicals, respectively.The measured value of k1 agrees with previous low-pressure (10 Torr) determinations verifying that reaction 1 is pressure independent.
- Kaiser, E. W.,Rimai, L.,Schwab, E.,Lim, E. C.
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- Preserved in a Shell: High-Performance Graphene-Confined Ruthenium Nanoparticles in Acetylene Hydrochlorination
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The potential implementation of ruthenium-based catalysts in polyvinyl chloride production via acetylene hydrochlorination is hindered by their inferior activity and stability compared to gold-based systems, despite their 4-fold lower price. Combining in-depth characterization and kinetic analysis we reveal the superior activity of ruthenium nanoparticles with an optimal size of 1.5 nm hosted on nitrogen-doped carbon (NC) and identify their deactivation modes: 1) nanoparticle redispersion into inactive single atoms and 2) coke formation at the metal sites. Tuning the density of the NC carrier enables a catalytic encapsulation of the ruthenium nanoparticles into single layer graphene shells at 1073 K that prevent the undesired metal redispersion. Finally, we show that feeding O2 during acetylene hydrochlorination limits coke formation over the nanodesigned ruthenium catalyst, while the graphene layer is preserved, resulting in a stability increase of 20 times, thus rivalling the performance of gold-based systems.
- Kaiser, Selina K.,Lin, Ronghe,Krumeich, Frank,Safonova, Olga V.,Pérez-Ramírez, Javier
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- Ethene Chlorination and Oxidative Coupling over Supported Mono- and Bi-metallic Chloride Catalysts
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Temperature-programmed reduction of metal chlorides upon silica, alumina, and titania supports using ethene produces chloroethene and 1,2-dichloroethane, together with rather unexpectedly, 1,1-dichloroethane and benzene in yields which differ from one metal chloride to another; results suggest the involvement of novel ..H/Cl.. exchange and oxidative-coupling reactions and also suggest that this technique of ethene titration may be of value in characterising the active sites in chloride catalysts and catalytic precursors.
- Rollins, Keith,Sermon, Paul A.
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- Influence of regeneration conditions on the activity of the catalyst for oxidative chlorination of ethylene
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The possibility of thermochemical regeneration of an industrial batch of a spent and partially deactivated catalyst to improve its activity and selectivity in oxidative chlorination of ethylene to give 1,2-dichloroethane was studied.
- Kurta,Mykytyn,Khaber
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- Unimolecular Rate Constants for Chemically Activated 1,1,1-Trifluoro-2-chloroethane: A Competitive Three-Channel System
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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.
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- ON THE THERMAL DECOMPOSITION OF 2,5-DIHYPOCHLORO-2,5-DIMETHYLHEXANE
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The title compound was prepared, characterized, and on thermal decomposition at 100 deg C in the presence of a chlorine atom trap was found to give acetone, 1,2-dichloroethane, and 4-chloro-2-methyl-2-butanol.
- Sanabia, J. Arce de,Cardenas, L. M. De,Mendez, N. Quiros
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- Deactivation factor of CuCl2-KCl/Al2O3 catalyst for ethylene oxychlorination in a commercial-scale plant
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Ethylene oxychlorination over a CuCl2-KCl/Al2O3 catalyst was examined for 2 consecutive years in a commercial-scale plant. The oxychlorination performance of the CuCl2-KCl/Al2O3 catalyst deteriorated gradually, which could seriously affect stable operation. To clarify such deactivation factors, the relationship between catalyst performance and physicochemical property change was investigated using X-ray fluorescence, electron probe microanalysis, and Brunauer–Emmett–Teller measurements. Sublimation of the CuCl component and subsequent increment of the ratio of K to Cu components were observed at the inlet of the catalyst bed, and were determined to be contributing factors in the deactivation of the CuCl2-KCl/Al2O3 catalyst.
- Ohashi, Tomokazu,Someya, Sae,Mori, Yoshihiko,Asakawa, Tetsuo,Hanaya, Makoto,Oguri, Motohiro,Watanabe, Ryo,Fukuhara, Choji
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Read Online
- Method for producing chloroethanol and dichloroethane through ethylene glycol chlorination
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The invention relates to a method for producing chloroethanol and dichloroethane through ethylene glycol chlorination. According to the method, ethylene glycol is taken as a raw material, a cobalt compound, a manganese compound and an iron compound are taken as active components, and a zinc compound is taken as an active catalyst of an active auxiliary agent, so that the reaction of chloroethanol and dichloroethane can be effectively catalyzed, and high chloroethanol yield is obtained. The method solves the problems of poor selectivity and difficulty in organic acid catalyst recovery in the chloroethanol and dichloroethane preparation reaction in the prior art, and also avoids the problems of high ethylene oxide production cost, difficulty in storage and transportation and the like in the chloroethanol process taking ethylene oxide as a raw material.
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Paragraph 0029-0076
(2021/08/11)
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- Method of Converting a Brominated Hydrocarbon to a Chlorinated Hydrocarbon
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The present invention provides a method of converting a brominated hydrocarbon to a chlorinated hydrocarbon that involves contacting together the brominated hydrocarbon and a chlorinated ion exchange resin that has a water content of less than or equal to 30 percent by weight, based on the total weight of the chlorinated ion exchange resin and the water. The brominated hydrocarbon includes at least one replaceable bromo group, where each replaceable bromo group is independently covalently bonded to an sp3 hybridized carbon. Contact between the brominated hydrocarbon and the chlorinated ion exchange resin results in replacement of at least one replaceable bromo group of the brominated hydrocarbon with a chloro group, and correspondingly conversion of at least a portion of the brominated hydrocarbon to the chlorinated hydrocarbon.
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Paragraph 0174-0177
(2021/02/19)
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- Continuous method for preparation of dihalogenated alkane from diol compound
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The invention discloses a continuous method for preparation of dihalogenated alkane from a diol compound. A diol compound and haloid acid are used as the substrate, a microchannel reactor is utilizedto synthesize dihalogenated alkane continuously. Synthesis of the dihalogenated alkane includes the steps of: inputting the diol compound and haloid acid into a mixer respectively by a metering pump at room temperature, conducting premixing, then sending the mixture into a high-temperature section of the microchannel reactor at for reaction, and controlling the reaction temperature by an externalcirculating heat exchange system; at the end of the reaction, letting the product flow out from an outlet of the microchannel reactor and enter a cooling section, letting the cooled material enter a liquid separation kettle for standing and liquid separation, and collecting an organic layer; and preheating the organic layer, then feeding the preheated organic layer into a rectifying tower by a metering pump, controlling the temperature and reflux ratio of a reboiler, and collecting fractions at a specific temperature, thus obtaining the target product in a product collecting tank. The method provided by the invention has the characteristics of high reaction efficiency, safety, environmental protection, convenience and rapidity.
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Paragraph 0037-0043
(2020/03/16)
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- Method for synthesizing 1,2-difluoroethane and 1,1,2-trifluoroethane
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The invention relates to a method for synthesizing 1,2-difluoroethane and 1,1,2-trifluoroethane, belonging to the field of organic chemical synthesis. The method for synthesizing 1,2-difluoroethane and 1,1,2-trifluoroethane is characterized in that ethylene (with a molecular formula of CH2=CH2) and chlorine (with a molecular formula of Cl2) are heated under the action of a catalyst to generate a mixture of 1,2-dichloroethane and 1,1,2-trichloroethane, and the mixture and hydrogen fluoride (with a molecular formula HF) are heated under the action of a fluorination catalyst to generate 1,2-difluoroethane and 1,1,2-trifluoroethane. According to the method, raw materials are low in process and convenient to obtain; product separation and purification are simple; industrial production is easy;and industrial three-waste generation amount is low.
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Paragraph 0022; 0024-0026; 0033-0034; 0037-0039; 0046-0047
(2020/05/30)
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- SYSTEMS AND METHODS USING LANTHANIDE HALIDE
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There are provided methods and systems related to use of one or more lanthanide halides in an electrochemical oxidation of metal halide in anolyte where the metal ion is oxidized from lower oxidation state to higher oxidation state at an anode; and then further use of the one or more lanthanide halides and the metal halide with the metal ion in the higher oxidation state in a halogenation reaction of an unsaturated hydrocarbon or a saturated hydrocarbon to form one or more products comprising halohydrocarbon.
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Paragraph 0234-0249
(2019/05/07)
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- Facile continuous process for gas phase halogen exchange over supported alkyl phosphonium salts
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Chloride-bromide halogen exchange was realized when a mixture of an alkyl chloride and an alkyl bromide were reacted over a supported molten alkyl phosphonium catalyst. Conversion was found to be near equilibrium in a tubular flow reactor at 150 °C and 1500 GHSV. The catalyst was prepared by impregnation of alumina or silica support and found to be highly stable for relatively long periods of time. A pathway for the catalytic cycle is proposed.
- Sharma, Priti,Sasson, Yoel
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p. 2824 - 2828
(2018/02/06)
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- 1, 2 - dichloroethane production
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PROBLEM TO BE SOLVED: To provide a novel method for manufacturing 1,2-dichloroethane capable of manufacturing, from ethylene in a high yield, 1,2-dichloroethane useful as a raw ingredient of a vinyl chloride monomer.SOLUTION: The provided method for manufacturing 1,2-dichloroethane uses, on an occasion for manufacturing 1,2-dichloroethane by inducing, in the presence of an oxychlorination catalyst, an oxychlorinating reaction of ethylene, hydrogen chloride, and air, a serial oxychlorination reaction process equipped with at least two fixed bed circulation-type catalytic reaction columns and executes an oxychlorinating reaction by filling, into the rearmost downstream-side fixed bed circulation-type catalytic reaction column of the serial oxychlorination catalytic reaction process, a hollow cylindrical oxychlorination catalyst (1) including, within a carrier, at least copper chloride and one or more types of metal cation halides having coordinated water exchanging reaction velocities of below 1×10sat 298K.
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Paragraph 0045-0047
(2017/05/04)
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- CATALYST AND PROCESS FOR OXYCHLORINATION OF ETHYLENE TO DICHLOROETHANE
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In an oxychlorination process of the type where ethylene is converted to 1,2-dichloroethane in the presence of a supported copper catalyst, the improvement comprising: the use of a supported catalyst prepared by (i) impregnating, within a first step, an alumina support with a first aqueous solution including copper, to thereby form a first catalyst component; and (ii) impregnating, within a subsequent step, the first catalyst component with a second aqueous solution including copper and alkaline earth metal, to thereby form the supported catalyst.
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Paragraph 0040
(2017/06/07)
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- PROCESS FOR THE PRODUCTION OF VINYL CHLORIDE, HEAVIES, AND HYDROGEN CHLORIDE FROM ETHANE
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A process is provided for the chlorination of ethane using chlorine as the chlorinating agent to produce hydrogen chloride (HCl) and vinyl chloride (VCM) and heavies.
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Page/Page column 5-6
(2016/06/06)
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- Reactivity of [WCl6] with Ethers: A Joint Computational, Spectroscopic and Crystallographic Study
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The reactions of [WCl6] with a series of ethers have been performed in chlorinated solvent and elucidated by means of analytical, spectroscopic and DFT methods. The addition of tetrahydropyran (thp) or 1,4-dioxane to [WCl6] resulted in the reversible formation of the adducts WCl6···L [L = thp (1a), 1,4-dioxane (1b)], detected in solution by NMR spectroscopy. The reaction of [WCl6] with thp in a molar ratio of 1:2 in chloroform at reflux afforded [WOCl4(thp)] (2a), which was isolated in 51 % yield. [WOCl4(OMe2)] (2b) and [WOCl3(OMe2)2] (3a) were isolated in yields of 53 and 18 %, respectively, from the reaction of [WCl6] with an excess of dimethyl ether. [WOCl3(OEt2)2] (3b) was the only identified metal compound produced from the reaction of [WCl6] and OEt2(1:2 molar ratio). According to NMR studies, the oxide ligand in 2a,b and 3a,b was generated by double C–O bond cleavage involving one equivalent of organic reactant. The 1:1 reaction of [WCl6] with 1,2-diethoxyethane led to [WCl5(κ1-OCH2CH2OEt)] (4) and a minor amount of [WCl4(κ2-EtOCH2CH2OEt)] (5). The aryl oxide compound [WCl5(OPh)] (6) was prepared in 62 % yield from the reaction of [WCl6] and anisole by selective Csp3–O bond activation. The prolonged heating of a mixture of [WCl6] and diphenyl ether in 1,2-dichloroethane led to the isolation of the WVcomplex [WCl5(OPh2)] (7). The molecular structures of 2a and 3a were ascertained by X-ray diffraction.
- Bortoluzzi, Marco,Marchetti, Fabio,Pampaloni, Guido,Zacchini, Stefano
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p. 3169 - 3177
(2016/07/14)
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- ELECTROCHEMICAL HYDROXIDE SYSTEMS AND METHODS USING METAL OXIDATION
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There are provided methods and systems for an electrochemical cell including an anode and a cathode where the anode is contacted with a metal ion that converts the metal ion from a lower oxidation state to a higher oxidation state. The metal ion in the higher oxidation state is reacted with an unsaturated hydrocarbon and/or a saturated hydrocarbon to form products. Separation and/or purification of the products as well as of the metal ions in the lower oxidation state and the higher oxidation state, is provided herein.
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Paragraph 0310-0314
(2015/02/19)
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- Electrochemical hydroxide systems and methods using metal oxidation
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There are provided methods and systems for an electrochemical cell including an anode and a cathode where the anode is contacted with a metal ion that converts the metal ion from a lower oxidation state to a higher oxidation state. The metal ion in the higher oxidation state is reacted with hydrogen gas, an unsaturated hydrocarbon, and/or a saturated hydrocarbon to form products.
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Page/Page column 97-98
(2015/12/04)
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- METHOD FOR PRODUCING 1,2-DICHLOROETHANE
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PROBLEM TO BE SOLVED: To provide a method for producing 1,2-dichloroethane from ethylene, hydrochloric acid, and air by an oxyclorination catalytic reaction process including at least two and, moreover, tandem fixed-bed circulation-type catalyst reaction towers, which method enables 1,2-dichloroethane to be produced in high selectivity and in high yield. SOLUTION: There is provided a method for producing 1,2-dichloroethane, in which catalysts filled in the last catalyst reaction tower includes two kinds of oxychlorination catalysts, i.e., low activity and high activity, catalysts formed of hollow cylindrical granules containing copper chloride, an alkali metal chloride, and magnesium chloride which are supported by alumina; and the low activity catalyst is filled at an entrance side of the reaction tower where raw materials are introduced, and the high activity catalyst is filled in an outlet side of the reaction tower. COPYRIGHT: (C)2015,JPOandINPIT
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Paragraph 0047-0051; 0054-0055
(2017/08/05)
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- Antibacterial piperidinyl substituted 3,4-dihydro-1H-[1,8]naphthyridinones
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The present invention is related to novel compounds of formula (I) that inhibit the activity of the Fab1 enzyme which are therefore useful in the treatment of bacterial infections. It further relates to pharmaceutical compositions comprising these compounds, and chemical processes for preparing these compounds.
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Page/Page column
(2014/06/24)
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- Further insights into the chemistry of niobium and tantalum pentahalides with 1,2-dialkoxyalkanes: Synthesis of bromo- and iodoalkoxides, spectroscopic and computational studies
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The room temperature reactions of a series of 1,2-dialkoxyalkanes ROCH 2CH(R′)OR′′ with MX5 (M = Nb, Ta; X = Br, I) in 1:1 ratio result in single C-O bond cleavage and high-yield formation of the halo-alkoxides MBr4[κ2-OCH 2CH(R′)OR′′] or [NbI4{κ 1-OCH2CH(R′)OR′′}]2, and equimolar amounts of the corresponding alkyl halides RX. The reaction of NbBr5 with 1,2-dimethoxyethane, dme, proceeds with preliminary formation of the ionic species [NbBr4(κ2-dme) (κ1-dme)][NbBr6], 3b, which has been identified by solution NMR at low temperature and conductivity analyses. The gas-phase structure of 3b has been optimized by DFT calculations, confirming that the dme ligands adopt bidentate and monodentate coordination, respectively. Although the formation of NbOBr3(dme), 4b, 1,4-dioxane and MeBr from NbBr 5/dme (ratio 1:2) is an exoergonic process (calculated ΔGr° = -115.96 kcal mol-1), it is inhibited at room temperature. High temperature conditions enhance the production of 1,4-dioxane at the expense of selectivity. The dinuclear species NbOBr3(dme)NbBr5 (Nb-O-Nb), 5b, (X-ray) has been isolated in modest yield as byproduct of the room temperature reaction of NbBr5 with dme. In general, the 1:2 molar reactions of NbX5 (X = Br, I) with ROCH2CH(R′) OR′′ occur with the exclusion of nearly one equivalent of organic reactant.
- Bini, Riccardo,Marchetti, Fabio,Pampaloni, Guido,Zacchini, Stefano
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experimental part
p. 1412 - 1419
(2011/06/22)
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- METHOD OF OBTAINING 1,2-DICHLOROETHANE BY DIRECT CHLORINATION WITH A STEP OF SEPARATION FROM THE CATALYST BY DIRECT EVAPORATION, AND FACILITY FOR THE IMPLEMENTATION THEREOF
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The present invention relates to a method of producing liquid 1,2-dichloroethane (DCE), obtained by low-temperature direct chlorination of ethylene, in the presence of a Lewis acid-type catalyst, that makes it possible to obtain, after separation of the catalyst, DCE of sufficient purity to give, via cracking, vinyl chloride monomer (VCM); characterized in that it comprises a step of dechlorination (5) of the liquid DCE stream (4) exiting the chlorination reactor (1), that makes it possible to remove the excess dissolved chlorine, followed by a step of direct evaporation (9) of the whole of the liquid DCE stream (8) exiting said reactor, that makes it possible to separate the catalyst from the evaporated fraction (10) of the stream of DCE good for cracking. The invention also relates to the plant for the implementation of such a method.
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Page/Page column 3
(2010/03/02)
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- CATALYSTS FOR OXYCHLORINATION OF ETHYLENE TO 1.2-DICHLOROETHANE
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Catalysts for the oxychlorination of ethylene to 1.2-dichloroethane, in form of hollow granules having definite geometrical configuration and pore volume distribution with at least 20% of the total volume formed of macropores wherein the diameter of the pores at the maximum of the macropore distribution curve is higher than 800 nm and up to 1500 nm.
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Page/Page column 2-4
(2010/06/22)
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- OXYCHLORINATION CATALYST
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Process for the oxychlorination of ethylene to form 1,2-dichloroethane in the gas recycle mode with reduced accumulation of hydrogen, which comprises the following steps: (A) introduction of ethylene, oxygen and hydrogen chloride as starting materials into an oxychlorination reactor, with the hydrogen chloride comprising hydrogen,(B) reaction of the starting materials over a catalyst comprising from 3.5 to 12.5% by weight of copper as copper saltfrom 0.1 to 1.0% by weight of magnesium as magnesium saltfrom 0.1 to 2.0% by weight of potassium as potassium salt on a support material to form 1,2-dichloroethane and water with at least partial conversion of the hydrogen present into water, (C) work-up of the reactor output and recirculation of the recycle gas to the oxychlorination reactor.
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Page/Page column 3-4
(2010/12/26)
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- REACTOR AND METHOD FOR REACTING AT LEAST TWO GASES IN THE PRESENCE OF A LIQUID PHASE
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A reactor for reacting at least two gases in the presence of a liquid phase, provided with an external liquid phase circulation device and including at least one injector for injecting the gases and the externally circulated liquid phase. In the injector the mixing of the gases together and with the externally circulated liquid phase only begins at the outlet of the injector.
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Page/Page column 3
(2009/07/25)
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- FUNCTIONALIZED POLYMERS USING PROTECTED THIOLS
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A process for the preparation of functional molecules using the thiol-ene coupling reaction and a process for the preparation of protected functional thiols, specifically thioesters is provided. The methods may be used to make functional polymers and other molecules. The method of making a functionalized polymer using a thiol-ene reaction comprises: providing a functionalized thioester having the following formula: (I) wherein R is a functional group and COR' is a protecting group; cleaving the functionalized thioester, forming a functional thiol and an acyl group; providing a polymer having a pendant vinyl group; and reacting the polymer with the functional thiol whereby a functionalized polymer is formed, wherein the functional thiol is not isolated prior to reacting with the polymer.
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Page/Page column 29-30
(2009/05/28)
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- Highly chemoselective Pd-C catalytic hydrodechlorination leading to the highly efficient N-debenzylation of benzylamines
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(Equation Presented) In the presence of 1,1,2-trichloroethane, a novel procedure for the Pd-C catalytic N-debenzylation of benzylamines was established. The method proceeded in a synergistic catalytic system and directly gave the products as crystal amine hydrochlorides in practically quantitative yields.
- Cheng, Chuanjie,Sun, Jianwei,Xing, Lixin,Xu, Jimin,Wang, Xinyan,Hu, Yuefei
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supporting information; experimental part
p. 5671 - 5674
(2009/12/08)
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- METHOD OF PREPARING DICHLOROPROPANOL FROM GLYCEROL USING HETEROPOLYACID CATALYSTS
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Provided is a method of preparing dichloropropanol from glycerol. According to the method, glycerol is reacted with a chlorinating agent using a heteropolyacid catalyst to prepare dichloropropanol. Accordingly, dichloropropanol can be directly prepared from glycerol by using heteropolyacid catalysts, and conventional problems such as recovery of the catalyst and separation of an azeotropic mixture including the catalyst and the products can be overcome. In addition, since the catalyst can be easily recovered and reused, the manufacturing process can be simplified and expensive dichloropropanol can be produced at high yield from inexpensive glycerol.
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Page/Page column 6-7; 8
(2009/07/17)
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- METHOD FOR PREPARING CHLORINATED COMPOUND FROM SATURATED HYDROCARBON
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The present invention relates to a method for preparing chlorinated compounds from saturated hydrocarbon. More particularly, the present invention relates to the method for preparing chlorinated compounds by conducting alternately an oxidation reaction of a catalyst under oxygen and hydrogen chloride, and a chlorination reaction for converting the saturated hydrocarbon into the chlorinated compounds by using the catalyst. The present invention has the advantages that the conversion rate of the saturated hydrocarbon may be enhanced; there is no need to consider erexplosion hazards; unreacted hydrogen chloride and corrosion of reactor may be reduced; a separate device for separating COx in exhaust gases may not be required since CO or CO2 is not produced in a combustion reaction; by-product may not be generated; and the durability of a catalyst may be remarkably enhanced.
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Page/Page column 14-16
(2009/04/25)
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- Method for Producing 1,2-Dichloroethane by Means of Direct Chlorination
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The invention relates to a method for producing high-purity 1,2-dichloroethane from dissolved chlorine and dissolved ethylene which are brought into contact with each other using a circulating liquid reaction medium which essentially consists of 1,2-dichloroethane and a catalyst and passes through at least one reaction loop. The two limbs of the loop are connected to a gas-phase stripping container which is arranged at the top and from which the reaction product is outwardly transferred either in a gaseous or liquid form or both in a gaseous form and in a liquid form. The addition points for the addition of chlorine and dissolved ethylene are arranged in the limb of the loop in which the liquid rises. The addition point for dissolved chlorine is always arranged downstream of the ethylene addition point. At least one addition point for liquid 1,2-dichloroethane follows each chlorine addition point, and the addition of the liquid 1,2-dichloroethane is carried out under kinetic energy which is high enough to enable a vigorous mixture of 1,2-dichloroethane, dissolved chlorine and ethylene to be carried out. Preferably, the liquid 1,2-dichloroethane is added by means of at least one jet mixer.
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Page/Page column 1; 5
(2008/12/06)
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- METHOD AND APPARATUS FOR PREPARING VINYL CHLORIDE USING ETHANE AND 1,2-DICHLOROETHANE
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The present invention provides a method and apparatus for preparing vinyl chloride in which reaction yield is improved and problems caused by coke generated during reactions can be solved. According to an aspect of the present invention, there is provided a method of preparing vinyl chloride comprising: supplying chlorine gas and ethane to an ethane chlorination reaction region disposed in a lower portion of a pyrolysis reactor in which solid particles exist; performing an ethane chlorination reaction by contacting the chlorine gas and ethane with solid particles such that a product of the ethane chlorination reaction and the solid particles rise toward an upper portion of the pyrolysis reactor at the same time, and depositing coke produced during the ethane chlorination reaction on the solid particles; performing a pyrolysis reaction in a pyrolysis reaction region disposed in an upper portion of the pyrolysis reactor by contacting a product of the ethane chlorination reaction with the solid particles such that the product of the ethane chlorination reaction and the solid particles rise up at the same time, and depositing coke produced during the pyrolysis reaction on the solid particles; separating solid particles obtained from the pyrolysis reaction and a product of the pyrolysis reaction in a separator; moving the separated solid particles to a regeneration reactor, and then burning coke deposited on the solid particles to regenerate the solid particles; and resupplying the regenerated solid particles to the pyrolysis reactor. According to another aspect of the present invention, there is provided an apparatus of preparing vinyl chloride comprising: a pyrolysis reactor comprising an ethane chlorination reaction region in a lower portion thereof and a pyrolysis reaction region in an upper portion thereof; a separator that separates a product of a pyrolysis reaction and solid particles; and a regeneration reactor that regenerates the separated solid particles by burning. When vinyl chloride is prepared using the method and apparatus according to the present invention, reaction yield is improved, and coke production and following coke accumulation in reactor can be inhibited.
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Page/Page column 4-5
(2008/06/13)
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- Catalyst composition for oxychlorination
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The present invention relates to a catalyst composition for the oxychlorination of ethylene, comprising a mixture of metal salts on a support, where said metal salts are applied to the support in such ratios that the catalyst composition comprises a) from 3 to 12% by weight of copper as copper salt, b) from 0 to 3% by weight of an alkaline earth metal as alkaline earth metal salt, c) from 0 to 3% by weight of an alkaline metal as alkaline metal salt, d) from 0.001 to 0.1% by weight, preferably from 0.005 to 0.05% by weight, of at least one metal selected from the group consisting of ruthenium, rhodium, palladium, osmium, iridium and platinum, and/or from 0.0001 to 0.1% by weight, preferably from 0.001 to 0.05% by weight, of gold, as corresponding metal salt or tetrachloroauric acid, where all percentages by weight are based on the total weight of the catalyst including support material. The invention further provides a process for preparing 1,2-dichloroethane by oxychlorination of ethylene in the presence of the above catalyst composition as catalyst.
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Page/Page column 3
(2008/06/13)
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- METHOD AND DEVICE FOR PRODUCING 1,2-DICHLORETHANE BY MEANS OF DIRECT CHLORINATION
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The invention relates to a method for the production of 1,2-dichlorethane having a high purity of dissolved chlorine and dissolved ethylene, which are brought into contact with each other using a liquid reaction medium which is guided in a circulating manner, said reaction medium being made of, essentially, 1,2-dichlorethane, a catalyst and at least one reaction path which is embodied as a loop and which extends in a vertical manner. The two limbs of the loop are connected to a waste gas container which is arranged on the top side, from which either a gas or fluid or either gas and also fluid is outwardly transferred from the reaction product. A plurality of additional sections are arranged in the limb of the loop, wherein the liquid rises, and each of said additional sections comprises a supply of dissolved or gaseous ethylene which is arranged upstream and a supply of dissolved chlorine which is arranged downstream, and can also comprise static mixing devices.
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Page/Page column 1; 5-8
(2008/06/13)
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- PROCESS FOR PREPARING EPICHLOROHYDRIN FROM ETHANE
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A process for preparing epichlorohydrin comprises (1) converting ethane to 1,2-dichloroethylene (cis/trans mixture) in the presence of a catalyst; (2) producing 2,3-dichloropropanal by (a) hydroformylating the 1,2-- dichloroethylene in the presence of a catalyst, carbon monoxide, and hydrogen, (b) adding MeOH to the 1,2-dichloroethylene, or (c) subjecting the 1,2-dichloroethylene to direct reductive hydroformylation in the presence of a reductive hydroformylation catalyst; and (3) epoxidizing the 2,3-DCH with a base to produce epichlorohydrin.
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Page/Page column 11-12
(2008/06/13)
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- Supported catalyst containing pseudo-boehmite and γ-Al2O3, production of same and its use for producing 1,2-dichloroethane
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A process for preparing 1,2-dichloroethane by reacting about 2 mols of ethylene, about 4 mols of hydrogen chloride and about 1 mol of oxygen in the presence of a fixed bed of supported catalyst based on copper(II) chloride in only one reaction zone at a pressure of from 2 to 10 bar and at from 220 to 280° C., separating off 1,2-dichloroethane and water from the reaction mixture emerging from the reaction zone and passing most of the exhaust gas back into the reaction zone, where, prior to entry into the reaction zone, the exhaust gas is mixed with ethylene, hydrogen chloride and oxygen, and the oxygen content of the mixture does not exceed 7% by volume, and where the ethylene content of the gas mixture entering into the reaction zone is regulated so that the exhaust gas comprises less than 20% by volume of ethylene, where the supported catalyst used is obtained by tableting a mixture of pseudoboehmite and γ-Al2O3in a weight ratio from 4:1 to 1:4, if desired with addition of tableting auxiliaries, loading this support with the active components by saturating with a CuCl2/KCl solution so that the copper content is from 1 to 15% by weight and the potassium content is from 0.1 to 8% by weight, based in each case on the total weight of the catalyst, and then drying the catalyst at from 60 to 400° C.
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Page column 4-5
(2008/06/13)
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- Method and device for utilizing heat in the production of 1,2-dichloroethane
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The invention relates to a method for the production of 1,2-dichloroethane by direct chlorination using chlorine and ethene in which, despite low reaction temperatures during direct chlorination, reaction heat produced is nevertheless used. According to the invention, vaporous 1,2-dichloroethane obtained in the direct chlorination reactor is compressed and the compressed 1,2-dichloroethane is transported to heat exchangers whereby heat is given off by the 1,2-dichloroethane. The invention also relates to a device including a turbocompressor arranged directly after the direct chlorination reactor.
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Page column 3-4
(2008/06/13)
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- METHOD AND DEVICE FOR EXPLOITING HEAT RESULTING FROM THE PRODUCTION OF 1,2-DICHLOROETHANE
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The invention relates to a method and a device for the optimal use of reaction heat resulting from the production of 1,2-dichloroethane from ethene and chlorine. The aim of the invention is achieved by extracting reaction heat liberated during the reaction of chlorine with ethene and the reaction heat contained in 1,2-dichloroethane. Extraction of said reaction heat from the reaction chamber occurs using at least one part of gaseous 1,2-dichloroethane (latent heat) and at least one part of liquid 1,2-dichloroethane (feelable heat) removed from the reaction chamber. Said reaction heat is used to heat two fractioning columns in order to purify 1,2-dichloroethane of impurities having a boiling point higher than 1,2-dichloroethane.
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- METHOD OF PRODUCING ETHYLENE (DI)CHLORIDE (EDC)
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With a method or a device for producing 1,2-dichloroethane or ethylene (di)chloride (EDC) with the use of a circulating reaction medium and a catalyst, whereby ethylene and chlorine are supplied to the reaction medium, the goal is to permit the catalytic chlorination of ethylene in a manner that is particularly gentle to the product.This is achieved in terms of the method and by other means in that the ethylene or chlorine gas are introduced into the reaction medium by means of microporous gas diffuser elements for producing gas bubbles with a diameter of 0.3 to 3 mm.
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- OXYCHLORINATION OF OLEFINS AND AROMATICS BY A NOVEL CONCEPT OF FLUIDIZED BED REACTION
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The invention concerns a method for continuous oxychlorination of olefins and aromatics, said method consisting in reacting olefins and aromatics as constituents (a) with oxygen and hydrochloric gas as constituents (b) in the presence of a copper salt catalyst in a reactor. The invention is characterized in that the constituents (a) and (b) are separately introduced in the space in the reaction zones and in the regeneration zones of the reactor. The reaction zone comprises a higher catalyst concentration in oxidized form when the solid matter is introduced than when it is extracted. The regeneration zone contains a higher catalyst concentration in reduced form when the solid matter is introduced than when it is extracted. The constituents (a) are set in the reaction zones and the constituents (b) in the regeneration zones.
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Page/Page column 2; 10; 11-12
(2008/06/13)
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- Catalysts for oxychlorination of ethylene to 1,2-dichloroethane
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Catalysts for oxychlorination of ethylene to 1,2-dichloroethane, comprising compounds of copper and magnesium supported on alumina, in which the copper, expressed as metal, is present in an amount of 7 to 12% by weight and the Mg/Cu ratio is 0.05 to 1, and wherein the ratio between the concentration of copper provided by the Al/Cu ratio at the surface and that provided by the Al/Cu ratio in the entire particle of the catalyst is from 0.8 to 1.3.
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- Comparative study on hydrolysis of 2-chloroethylphosphonic acid dialkylesters
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2-Chloroethylphosphonic acid dialkylesters (bis-(2-chloroethyl), dimethyl, diethyl, dipropyl, dibutyl and dipentylesters) were hydrolyzed in order to obtain 2-chloroethylphosphonic acid, used as a plant growth regulator. Experiments were made in neutral or acid conditions, in order to find optimal conditions for esters hydrolysis. The obtained 2-chloroethylphosphonic acid was tested, regarding its biological activity, on melon, cucumber, blackcurrant and bilberry.
- Ilia, Gheorghe,Cǎprita, Adrian,Iliescu, Smaranda,Popa, Adriana,Pascariu, Aurelia,Bora, Alina,Dehelean, Gheorghe
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p. 501 - 506
(2007/10/03)
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- Method of chlorine purification and process for producing 1,2-dichloroethane
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A method for chlorine purification in which crude chlorine containing nitrogen and/or oxygen is purified to separate the nitrogen and oxygen from the chloride, characterized in that the crude chlorine containing nitrogen and/or oxygen is contacted with 1,2-dichloroethane to cause the 1,2-dichloroethane to absorb the chlorine contained in the crude chlorine, and a process for producing 1,2-dichloroethane which comprises reacting ethylene with the chlorine contained in the chlorine containing 1,2-dichloroethane.
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- Preparation of intermediates useful in the synthesis of antiviral nucleosides
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The present invention is an efficient process for the manufacture of α-acyloxyacetaldehyde, a key intermediate in the synthesis of 1,3-oxathiolane and 1,3-dioxolane nucleosides.
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- Preparation of 1,2-dichloroethane
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A process for the preparation of 1,2-dichloroethane by oxychlorination of ethene in the presence of a copper-containing fixed-bed catalyst comprising a bed essentially consisting of catalyst particles which comprise, at least partially, support material impregnated with an active component and, if desired, a promoter, where the catalyst bed comprises essentially no separate inert material for dilution.
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Page column 1-3
(2008/06/13)
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- Benzothiophenes formulations containing same and methods
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This invention provides compounds of formula I and pharmaceutically acceptable salts and solvates thereof, characterized that the compound is in particulate form and having a specific size range. The present invention further provides pharmaceutical compositions containing or formulated using compounds of formula I, and the use of such compounds for alleviating human pathologies, including osteoporosis, serum lipid lowering, and breast cancer.
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- 2′-Fluoronucleosides
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A class of 2′-fluoro-nucleoside compounds are disclosed which are useful in the treatment of hepatitis B infection, hepatitis C infection, HIV and abnormal cellular proliferation, including tumors and cancer. The compounds have the general formulae: wherein Base is a purine or pyrimidine base; R1is OH, H, OR3, N3, CN, halogen, including F, or CF3, lower alkyl, amino, loweralkylamino, di(lower)alkylamino, or alkoxy, and base refers to a purine or pyrimidine base; R2is H, phosphate, including monophosphate, diphosphate, triphosphate, or a stabilized phosphate prodrug; acyl, or other pharmaceutically acceptable leaving group which when administered in vivo, is capable of providing a compound wherein R2is H or phosphate; sulfonate ester including alkyl or arylalkyl sulfonyl including methanesulfonyl, benzyl, wherein the phenyl group is optionally substituted with one or more substituents as described in the definition of aryl given above, a lipid, an amino acid, peptide, or cholesterol; and R3is acyl, alkyl, phosphate, or other pharmaceutically acceptable leaving group which when administered in vivo, is capable of being cleaved to the parent compound, or a pharmaceutically acceptable salt thereof.
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