- Kinetics of the Liquid-Phase Hydrochlorination of Ethanol
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The results of a study on the kinetics of the liquid-phase hydrochlorination of ethanol with hydrogen chloride are presented. The form of the rate equation, the preexponential factor, the activation energy, and the empirical coefficients that characterize the effect of chloride anion hydration on the reaction rate of ethanol hydrochlorination were determined. The rates of hydrochlorination of monohydric alcohols and polyols were compared based on the examples of methanol, ethanol, 1,2-propylene glycol, and glycerol.
- Makhin,Dmitriev,Zanaveskin
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- Stable C2H5X(1+). (X=Cl, Br) Radical Cations of Structure : Their Energetics and Dissociation Characteristics
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A new radical cation having the methyl carbene type structure (1+). has been characterized in the gas phase.It is readily generated by dissociative ionization (1+). -> CO2+(1+)..Its enthalpy of formation has been estimated to be 951 kJ mol-1, close to that of (1+)..The principal fragmentation characteristics (loss of HCl and Cl.) of the ion are discussed.A brief description of the bromo analogue (1+). is also given.
- Holmes, John L.,Burgers, Peter C.,Terlouw, Johan K.,Schwarz, Helmut,Ciommer, Bernhard,Halim, Herman
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- Electrophilic addition reaction of ethene with hydrogen chloride on cold molecular films: Evidence of ethyl cationic intermediate
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We studied the initial-stage mechanism of the electrophilic addition reaction of ethene with HCl by examining the interactions between ethene and HCl on water-ice and frozen molecular films at temperatures of 80-140 K. Cs + reactive ion scattering (RIS) and low-energy sputtering (LES) techniques were used to probe the reaction intermediates that were kinetically trapped on the surface, in conjunction with temperature-programmed desorption (TPD) mass spectrometry to monitor the desorbing species. The reaction initially produced the π complex of HCl and ethene at temperatures below about 93 K and an "ethyl cationic species" at temperatures below about 100 K. The ethyl cationic species was formed via direct proton transfer from the HCl molecule to ethene with the assistance of water solvation, rather than via the interaction of hydronium ions and ethene. At high temperatures, this species dissociated into ethene and hydronium and chloride ions. The reaction did not, however, complete the final transition state on the ice surface to produce ethyl chloride. The observation gives evidence that the electrophilic addition reaction of ethene occurs through an ethyl-like intermediate with an ionic character. A cold ice surface can halt a reaction at an intermediate stage. An ethyl cationic intermediate is kinetically trapped on the ice surface in the course of the electrophilic addition reaction of ethene with hydrogen chloride, as revealed by reactive ion scattering and thermal desorption mass spectrometry.
- Lee, Poong-Ryul,Lee, Chang-Woo,Kim, Joon-Ki,Moon, Eui-Seong,Kang, Heon
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Read Online
- 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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supporting information
p. 22080 - 22085
(2020/10/02)
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- Halogen-Dependent Surface Confinement Governs Selective Alkane Functionalization to Olefins
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The product distribution in direct alkane functionalization by oxyhalogenation strongly depends on the halogen of choice. We demonstrate that the superior selectivity to olefins over an iron phosphate catalyst in oxychlorination is the consequence of a surface-confined reaction. By contrast, in oxybromination alkane activation follows a gas-phase radical-chain mechanism and yields a mixture of alkyl bromide, cracking, and combustion products. Surface-coverage analysis of the catalyst and identification of gas-phase radicals in operando mode are correlated to the catalytic performance by a multi-technique approach, which combines kinetic studies with advanced characterization techniques such as prompt-gamma activation analysis and photoelectron photoion coincidence spectroscopy. Rationalization of gas-phase and surface contributions by density functional theory reveals that the molecular level effects of chlorine are pivotal in determining the stark selectivity differences. These results provide strategies for unraveling detailed mechanisms within complex reaction networks.
- Zichittella, Guido,Scharfe, Matthias,Puértolas, Bego?a,Paunovi?, Vladimir,Hemberger, Patrick,Bodi, Andras,Szentmiklósi, László,López, Núria,Pérez-Ramírez, Javier
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supporting information
p. 5877 - 5881
(2019/02/20)
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- Synthesis and reactivity of platinum vinylcarbene complexes prepared from activation of propargyl alcohols
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Platinum vinylcarbene complexes are potentially useful for organometallic synthesis and catalysis, but have been rarely studied. This work reports a convenient route to make platinum vinylcarbene complexes. Treatment of [PtCl2(PPh3)]2 with propargyl alcohols HC≡CC(OH)RR’ (RR’ = Ph2, cyclo-C6H10(OH), (iPr)(C≡CTMS) and (H)(Ph)) in the presence of EtOH produced the vinylcarbene complexes trans-PtCl2{ = C(OEt)-CH=CRR’}(PPh3). Under similar condition, [PtCl2(PPh3)]2 reacted with HC≡CC(OH)Me2 to give cis-PtCl2{ = C(OEt)-CH=CMe2}(PPh3). Complex trans-PtCl2{ = C(OEt)-CH=CPh2}(PPh3) readily undergo a metathesis reaction with NaI to give trans-PtI2{ = C(OEt)-CH=CPh2}(PPh3) which can isomerize to cis-PtI2{ = C(OEt)-CH=CPh2}(PPh3). Complex trans-PtCl2{ = C(OEt)-CH=CPh2}(PPh3) reacted with PPh3 to give EtCl and the acyl complex trans-PtCl{C(O)CH=CPh2}(PPh3)2, which can undergo a decarbonylation reaction to give PtCl(CH=CPh2)(PPh3)2.
- Ruan, Wenqing,Shi, Chuan,Sung, Herman H.Y.,Williams, Ian D.,Jia, Guochen
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- PROCESS AND INTERMEDIATE FOR THE MANUFACTURE OF DIFLUOROACETYL CHLORIDE
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The present invention concerns a process and intermediates for the manufacture of difluoro acetyl chloride. The invention further concerns a process for the manufacture of an agrochemically or pharmaceutically active compound, which comprises the process and intermediate for the manufacture of difluoro acetyl chloride for the manufacture of difluoro acetyl chloride or its intermediate.
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Page/Page column 14; 15
(2019/03/17)
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- Selective Photo-Oxygenation of Light Alkanes Using Iodine Oxides and Chloride
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Partial oxidation of light alkanes to generate alkyl esters has been achieved under photochemical conditions using mixtures of iodine oxides and chloride salts in trifluoroacetic acid (HTFA). The reactions are catalytic in chloride and are successful using compact fluorescent light, but higher yields are obtained using a mercury lamp. In this photo-initiated oxyesterification process, the robust alkyl ester products are resistant to over-oxidation, and under optimized conditions yields for alkyl ester production of ～50 % based on methane, ～60 % based on ethane (with a total functionalized yield of EtX (X=TFA or Cl) of 80 %) and ～30 % based on propane have been demonstrated. The reaction also proceeds in aqueous HTFA and dichloroacetic acid with lower yields. Mechanistic studies indicate that the process likely operates by a chlorine hydrogen atom abstraction pathway wherein alkyl radicals are generated, trapped by iodine, and converted to alkyl trifluoroacetates in situ.
- Liebov, Nichole S.,Goldberg, Jonathan M.,Boaz, Nicholas C.,Coutard, Nathan,Kalman, Steven E.,Zhuang, Thompson,Groves, John T.,Gunnoe, T. Brent
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p. 5045 - 5054
(2019/10/28)
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- An Activated TiC–SiC Composite for Natural Gas Upgrading via Catalytic Oxyhalogenation
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Alkane oxyhalogenation has emerged as an attractive catalytic route for selective natural gas functionalization to important commodity chemicals, such as methyl halides or olefins. However, few systems have been shown to be active and selective in these reactions. Here, we identify a novel and highly efficient TiC–SiC composite for methane and ethane oxyhalogenation. Detailed characterization elucidates the kinetics and mechanism of the selective activation under reaction conditions to yield TiO2–TiC–SiC. This catalyst outperforms bulk TiO2, one of the best reported catalysts, reaching up to 85 % selectivity and up to 3 times higher titanium-specific space-time-yield of methyl halides or ethylene. This is attributed to the fact that the active TiO2 phase generated in situ is embedded in the thermally conductive SiC matrix, facilitating heat dissipation thus improving selectivity control.
- Zichittella, Guido,Puértolas, Bego?a,Siol, Sebastian,Paunovi?, Vladimir,Mitchell, Sharon,Pérez-Ramírez, Javier
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p. 1282 - 1290
(2018/02/09)
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- Mechanism of Hydrocarbon Functionalization by an Iodate/Chloride System: The Role of Ester Protection
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Mixtures of chloride and iodate salts for light alkane oxidation achieve >20% yield of methyl trifluoroacetate (TFA) from methane with >85% selectivity. The mechanism of this C-H oxygenation has been probed by examining adamantane as a model substrate. These recent results lend support to the involvement of free radicals. Comparative studies between radical chlorination and iodate/chloride functionalization of adamantane afford statistically identical 3°:2° selectivities (～5.2:1) and kinetic isotope effects for C-H/C-D functionalization (kH/kD = 1.6(3), 1.52(3)). Alkane functionalization by iodate/chloride in HTFA is proposed to occur through H-atom abstraction by free radical species including Cl? to give alkyl radicals. Iodine, which forms by in situ reduction of iodate, traps alkyl radicals as alkyl iodides that are subsequently converted to alkyl esters in HTFA solvent. Importantly, the alkyl ester products (RTFA) are quite stable to further oxidation under the oxidizing conditions due to the protecting nature of the ester moiety.
- Schwartz, Nichole A.,Boaz, Nicholas C.,Kalman, Steven E.,Zhuang, Thompson,Goldberg, Jonathan M.,Fu, Ross,Nielsen, Robert J.,Goddard, William A.,Groves, John T.,Gunnoe, T. Brent
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p. 3138 - 3149
(2018/04/14)
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- Process for synthesizing ethyl chloride
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The invention discloses a process for synthesizing ethyl chloride. In a closed reactor, an ethyl chloride product can be obtained from ethanol and hydrogen chloride gas under the catalytic effect of AlCl3-ZnCl2 double component catalyst by gradually heating for reaction, releasing step by step and recovering. The high activity of AlCl3-ZnCl2 double component catalyst is used in the method, reaction temperature and by-product diethyl ether are reduced, and the yield of the ethyl chloride is increased to above 95%; by the use of the hydrogen chloride for replacement of industrial hydrochloric acid, mother liquor and distillate are directly continuously applied, energy consumption for distillation distillate recovery and hydrogen chloride loss are effectively reduced, environment pollution caused by production of a lot of high salt wastewater and organic waste acid can be avoided; in addition, by use of a closed staged heating reaction way, a catalytic substitution reaction is performed in a liquid phase system, substrate contact reaction time is increased, ethanol conversion rate reduction caused by too fast escaping of excessive hydrogen chloride from the reactor can be avoided, the consumption increase of the hydrogen chloride is avoided, and the atmospheric pollution is reduced.
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Paragraph 0026; 0027; 0028; 0029; 0030; 0031-0038
(2017/04/29)
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- Continuous production method of ethyl chloride
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The invention discloses a continuous production method of ethyl chloride. The method comprises the following steps: (1) mixing: preheating ethanol to 50-100 DEG C by a preheater, sending the ethanol into a mixing tube, sufficiently mixing with hydrogen chloride gas, and continuously introducing the mixture into a reaction kettle; (2) reaction: preparing a zinc chloride water solution in a reaction kettle, carrying out reaction on the chlorine hydride and ethanol at 100-160 DEG C under the pressure of 0.01-0.2 MPa under the action of zinc chloride to remove water, condensing the gas-phase system by a condenser to obtain a gas-phase ethyl chloride crude product and a condensate, and returning the condensate to the reaction kettle; and (3) refinement: sequentially passing the ethyl chloride crude product through a two-stage water absorption tower, a two-stage sulfuric acid drying tower and a sulfuric acid demister, and liquefying by compression to obtain the ethyl chloride finished product. The temperature of the ethanol is enhanced before the reaction, and the chlorine hydride and ethanol are mixed, thereby enhancing the reaction rate; and the method has the advantages of high conversion rate of ethanol, low productive energy consumption and high product purity.
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Paragraph 0027; 0028; 0029; 0030; 0031; 0032; 0033-0044
(2017/07/19)
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- Synthesis method of triethyl phosphonoacetate
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Relating to the field of organic compound synthesis, the invention provides a synthesis method of triethyl phosphonoacetate. Triethyl phosphate and ethyl chloroacetate are taken as the raw materials to carry out Michael arbuzov rearrangement reaction, thus obtaining triethyl phosphonoacetate. The chemical reaction formulas of the synthesis method are: CH2ClCOOH+C2H5OH to C4H7ClO2+H2O, C4H7ClO2+C6H15O3P to C8H17O5P+C2H5Cl. The method provided by the invention solves the problems of high energy consumption, high cost and low product purity in the traditional process, also solves the problem of byproduct application in a synthetic environment, and achieves good economic and social benefits.
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Paragraph 0017; 0019; 0021; 0024; 0026; 0029; 0031
(2017/08/27)
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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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- Formamides as Lewis Base Catalysts in SNReactions—Efficient Transformation of Alcohols into Chlorides, Amines, and Ethers
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A simple formamide catalyst facilitates the efficient transformation of alcohols into alkyl chlorides with benzoyl chloride as the sole reagent. These nucleophilic substitutions proceed through iminium-activated alcohols as intermediates. The novel method, which can be even performed under solvent-free conditions, is distinguished by an excellent functional group tolerance, scalability (>100 g) and waste-balance (E-factor down to 2). Chiral substrates are converted with excellent levels of stereochemical inversion (99 %→≥95 % ee). In a practical one-pot procedure, the primary formed chlorides can be further transformed into amines, azides, ethers, sulfides, and nitriles. The value of the method was demonstrated in straightforward syntheses of the drugs rac-Clopidogrel and S-Fendiline.
- Huy, Peter H.,Motsch, Sebastian,Kappler, Sarah M.
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supporting information
p. 10145 - 10149
(2016/08/16)
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- Associative vs. dissociative mechanism of P]C bond breaking in α-aminophosphonates leading to phosphoric acid [P(V)] derivatives
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The α-aminophosphonates are relatively easily protonated on phosphoryl oxygen in acidic conditions due the neighboring amine group effect. Protonation of phosphoryl oxygen makes the phosphorus atom highly electrophilic and suitable for decomposition with P-C bond breaking to PIII or PV decomposition products. The process of decomposition to PIII products has a large positive entropy value (198.8 [J/K.mol]) which indicates an elimination mechanism. High negative entropy of activation-72 [J/K.mol] for decomposition to PV derivatives-suggests that it undergoes a nucleophilic substitution mechanism via a trigonal-bipyramidal intermediate or transition state. Many other arguments for such a statement are discussed. [PRESENTED EQUATION]
- Gancarz, Roman,Kiersnowska, Agnieszka Deron
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p. 285 - 302
(2017/03/09)
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- Trichloroisocynuric acid/DMF as efficient reagent for chlorodehydration of alcohols under conventional and ultrasonic conditions
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A new and efficient method for the chlorodehydration of alcohols utilizing TCCA/DMF is described. Various alcohols can be converted smoothly into their corresponding alkyl chlorides in high yields under mild conditions with short reaction times. Taylor & Francis Group, LLC.
- Venkana, Purugula,Kumar, Mukka Satish,Rajanna, Kamatala Chinna,Ali, Mir Moazzam
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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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supporting information
p. 5294 - 5298
(2015/03/30)
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- Rapid degradation of cyclic peroxides by titanium and antimony chlorides
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First responders face extraordinary risks when dealing with organic peroxides such as TATP due to the extreme sensitivity of this class of explosives, and to a lack of a robust chemical means of safe and rapid neutralisation. The Lewis acids TiCl4 and SbCl3 have been found to demonstrate a novel degradation mechanism, with TiCl4 degrading a model cyclic peroxide in minutes when used in a two-fold excess, or ～3 hours at half equivalence. The products cannot re-form peroxide compounds as is the case with acid degradation, suggesting the two mechanisms are fundamentally different. The Lewis acids mediate a rearrangement reaction in the cyclic peroxide backbone leading to relatively innocuous products through deactivation of oxidising O. Sub-stoichiometric TiCl4 reactions highlight a secondary reaction pathway that also leads to some oxidative chlorination products, possibly mediated by an unconfirmed titanium-oxychloride species. SbCl3 was found to exhibit similar reactivity to TiCl4, although at a slower rate. A mechanism is proposed, consistent with the observations for both stoichiometric and sub-stoichiometric quantities of TiCl4.
- Bali, Mark S.,Armitt, David,Wallace, Lynne,Day, Anthony I.
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p. 6775 - 6783
(2015/04/14)
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- Unexpectedly Stable (Chlorocarbonyl)(N-ethoxycarbonylcarbamoyl)disulfane, and Related Compounds That Model the Zumach-Weiss-Kühle (ZWK) Reaction for Synthesis of 1,2,4-Dithiazolidine-3,5-diones
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The Zumach-Weiss-Kühle (ZWK) reaction provides 1,2,4-dithiazolidine-3,5-diones [dithiasuccinoyl (Dts)-amines] by the rapid reaction of O-ethyl thiocarbamates plus (chlorocarbonyl)sulfenyl chloride, with ethyl chloride and hydrogen chloride being formed as coproducts, and carbamoyl chlorides or isocyanates generated as yield-diminishing byproducts. However, when the ZWK reaction is applied with (N-ethoxythiocarbonyl)urethane as the starting material, heterocyclization to the putative "Dts-urethane"? does not occur. Instead, the reaction directly provides (chlorocarbonyl)(N-ethoxycarbonylcarbamoyl)disulfane, a reasonably stable crystalline compound; modified conditions stop at the (chlorocarbonyl)[1-ethoxy-(N-ethoxycarbonyl)formimidoyl]disulfane intermediate. The title (chlorocarbonyl)(carbamoyl)disulfane cannot be converted to the elusive Dts derivative, but rather gives (N-ethoxycarbonyl)carbamoyl chloride upon thermolysis, or (N-ethoxycarbonyl)isocyanate upon treatment with tertiary amines. Additional transformations of these compounds have been discovered, providing entries to both known and novel species. X-ray crystallographic structures are reported for the title (chlorocarbonyl)(carbamoyl)disulfane; for (methoxycarbonyl)(N-ethoxycarbonylcarbamoyl)disulfane, which is the corresponding adduct after quenching in methanol; for [1-ethoxy-(N-ethoxycarbonyl)formimidoyl](N′-methyl-N′-phenylcarbamoyl)disulfane, which is obtained by trapping the title intermediate with N-methylaniline; and for (N-ethoxycarbonylcarbamoyl)(N′-methyl-N′-phenylcarbamoyl)disulfane, which is a short-lived intermediate in the reaction of the title (chlorocarbonyl)(carbamoyl)disulfane with excess N-methylaniline. The new chemistry and structural information reported herein is expected to contribute to accurate modeling of the ZWK reaction trajectory.
- Barany, George,Britton, Doyle,Chen, Lin,Hammer, Robert P.,Henley, Matthew J.,Schrader, Alex M.,Young, Victor G.
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p. 11313 - 11321
(2015/12/01)
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- Selective monooxidation of light alkanes using chloride and iodate
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We describe an efficient system for the direct partial oxidation of methane, ethane, and propane using iodate salts with catalytic amounts of chloride in protic solvents. In HTFA (TFA = trifluoroacetate), >20% methane conversion with >85% selectivity for MeTFA have been achieved. The addition of substoichiometric amounts of chloride is essential, and for methane the conversion increases from 20%. The reaction also proceeds in aqueous HTFA as well as acetic acid to afford methyl acetate. 13C labeling experiments showed that less than 2% of methane is overoxidized to 13CO2 at 15% conversion of 13CH4. The system is selective for higher alkanes: 30% ethane conversion with 98% selectivity for EtTFA and 19% propane conversion that is selective for mixtures of the mono- and difunctionalized TFA esters. Studies of methane conversion using a series of iodine-based reagents [I2, ICl, ICl3, I(TFA)3, I2O4, I 2O5, (IO2)2S2O 7, (IO)2SO4] indicated that the chloride enhancement is not limited to iodate.
- Fortman, George C.,Boaz, Nicholas C.,Munz, Dominik,Konnick, Michael M.,Periana, Roy A.,Groves, John T.,Brent Gunnoe
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p. 8393 - 8401
(2014/06/24)
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- Method for Producing Difluoroacetyl Chloride
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A production method of difluoroacetyl chloride according to the present invention includes a chlorination step of bringing a raw material containing at least either a 1-alkoxy-1,1,2,2-tetrafluoroethane or difluoroacetyl chloride into contact with calcium chloride at a reaction enabling temperature. A production method of 2,2-difluoroethyl alcohol according to the present invention includes a catalytic reduction step of causing catalytic reduction of the difluoroacetyl chloride obtained by the above production method. By these methods, the difluoroacetyl fluoride can be efficiently converted to the difluoroacetyl chloride and to the 2,2-difluoroethyl alcohol.
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Paragraph 0093
(2013/03/26)
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- Effect of catalyst pre-reduction temperature on the reaction of 1,2-dichloroethane and H2 catalyzed by SiO2-supported PtCu bimetallics
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A combination of reaction kinetics experiments, temperature-programmed investigations and FTIR CO adsorption studies were used to understand the effect of catalyst pretreatment on the reaction of 1,2-dichloroethane and H 2 catalyzed by SiO2 supported PtCu bimetallics prepared from metal chloride precursors. Higher initial and steady-state selectivities towards ethylene were obtained for catalysts with a Cu to Pt atomic ratio of 1, 2, and 3 after pre-reduction at 220 °C than after pre-reduction at 500 °C. For catalysts with a Cu to Pt atomic ratio of 4 and 5, the initial ethylene selectivity was higher after the 220 °C pre-reduction, but the steady-state ethylene selectivities were essentially the same. Based on the catalyst characterization results, the low temperature pre-reduction yields supported particles with Pt-rich cores covered with Cu-rich layers that are still well-chlorinated, whereas the high temperature pre-reduction yields particles both more metallic and with surfaces richer in Pt. The factors governing the evolution of the catalysts during the two different pretreatments are discussed as well as the impact catalyst pretreatment has on the macroscopic performance behavior.
- Akonwie, Lindney N.,Kazachkin,Luebke,D'Itri, Julie L.
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experimental part
p. 59 - 69
(2012/08/08)
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- Synthetic routes to, transformations of, and rather surprising stabilities of (N-Methyl-N-phenylcarbamoyl)sulfenyl Chloride, ((N-Methyl-N-phenylcarbamoyl) dithio)carbonyl chloride, and related compounds
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(Figure presented) The title compound classes, (carbamoyl)sulfenyl chlorides and ((carbamoyl)dithio)carbonyl chlorides, have been implicated previously as unstable, albeit trappable, intermediates in organosulfur chemistry. The presentwork reports for each of these functional groups: (i) several routes to prepare it in the N-methylaniline family; (ii) its direct structural characterization by several spectroscopic techniques; (iii) its rather unexpected stability and its ultimate fatewhen it decomposes; (iv) a series of further chemical transformations that give highly stable derivatives, each in turn subject to thorough characterization. Relevant kinetic and mechanistic experiments were carried out, including some with p-methyl- and 2,6-dimethyl-substituted N-methylanilines. Given that the title compounds can be isolated and are relatively stable, they may find applications in the preparation of thiolyzable and/or photolabile protecting groups for the sulfhydryl function of cysteine and for the development of new protein synthesis and modification reagents
- Schrader, Alex M.,Schroll, Alayne L.,Barany, George
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experimental part
p. 7882 - 7892
(2011/12/14)
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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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experimental part
p. 5367 - 5376
(2010/08/04)
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- COMPOSITION THAT CAN BE CURED BY POLYMERISATION FOR THE PRODUCTION OF BIODEGRADABLE, BIOCOMPATIBLE, CROSS-LINKABLE POLYMERS ON THE BASIS OF POLYVINYL ALCOHOL
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The present invention relates to a polymerization-curable composition for the preparation of biodegradable, biocompatible, cross-linked polymers on the basis of polyvinyl alcohol comprising: 5 to 100% by weight of (a) vinyl ester monomer(s) of one of the general formulas (I) to (III): wherein X is oxygen, sulfur, nitrogen, or phosphorus; n is 1 to 1000, at least 20% of the n being ≧2; the R1 are selected from hydrogen; straight, branched or cyclic, saturated or unsaturated, n-valent hydrocarbon groups having 1 to 30 carbon atoms, which optionally have heteroatoms and are optionally substituted with one or more substituents selected from —OH, —COON, —CN, —CHO, and ═O, and n-valent radicals of biodegradable, biocompatible oligomers and polymers; m is an integer from 1 to 5; the R2 are selected from hydrogen, —OH, ═O, and the options listed for R1; and the R3 are selected from hydrogen, —OH, and the options listed for R1; 0 to 50% by weight of ethylenically unsaturated co-monomers; 0 to 10% by weight of (a) polymerization initiator(s); and 0 to 95% by weight of solvent(s).
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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
-
experimental part
p. 96 - 101
(2011/01/12)
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- METHOD FOR PREPARING CHLORINATED COMPOUND FROM SATURATED HYDROCARBON
-
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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- OXONIUM AND SULFONIUM SALTS
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The present invention relates to oxonium salts having [(Ro)3O]+ cations and sulfonium salts having [(Ro)3S]+ cations, where Ro denotes straight-chain or branched alkyl groups having 1-8 C atoms or phenyl which is unsubstituted or substituted by Ro, ORo, N(Ro)2, CN or halogen, and anions selected from the group of [PFx(CyF2y+1?zHz)6?x]? anions, where 2≦x≦5, 1≦y≦8 and 0≦z≦2y+1, or anions selected from the group of [BFn(CN)4?n]? anions, where n=0, 1 , 2 or 3, or anions selected from the group of [(Rf1SO2)2N]? anions or anions selected from the group of [BFwRf24?w]? anions, to processes for the preparation thereof, and to the use thereof, in particular for the preparation of ionic liquids.
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Page/Page column 14
(2009/03/07)
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- Vapor generation of inorganic anionic species after aqueous phase alkylation with trialkyloxonium tetrafluoroborates
-
Aqueous phase reaction of trialkyloxonium tetrafluoroborates, R 3O+BF4- (R=Me, Et) has been tested in the alkylation of simple inorganic anionic substrates such as halogen ions, cyanide, thiocyanate, sulphide an
- D'Ulivo, Alessandro,Pagliano, Enea,Onor, Massimo,Pitzalis, Emanuela,Zamboni, Roberto
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experimental part
p. 6399 - 6406
(2010/04/06)
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- Transformation of tertiary amines into alkylating reagents by treatment with 2-chloro-4,6-dimethoxy-1,3,5-triazine. A synthetic application of side-reaction accompanying coupling by means of 4-(4,6-dimethoxy-[1,3,5] triazin-2-yl)-4-methyl-morpholin-4-ium chloride (DMTMM)
-
Mild reaction conditions are described for the preparation of a number of alkyl chlorides and 2-dialkyl(aryl)amino-4,6-dirnethoxy-1,3,5-triazines by dealkylation of quaternary triazinylammonium chlorides formed as reactive intermediates in reaction of tertiary amines with 2-chloro-4,6-dimethoxy-1,3,5- triazine. The high selectivity of substitution was observed within the reactivity order of the alkyl groups: benzyl ～ allyl > methyl > n-alkyl. Studies on dealkylation of S-(-)-J-dimethyl-(1-phenylethyl)amine to R-(+)-1-chloro-1-phenylethane revealed that reaction proceeded with an inversion of configuration on the carbon atom as may be expected for SN2 type substitution. The scope of reaction was extended by exchange of anion in quaternary triazinylammonium chlorides with 1-, SCN-, C6H5O-, CH3COO- followed by N-dealkylation step.
- Kolesinska,Kaminski
-
experimental part
p. 2115 - 2123
(2009/04/07)
-
- Selective formation of chloroethane by the hydrochlorination of ethene using zinc catalysts
-
A detailed study of the hydrochlorination of ethene and higher alkenes using ZnCl2/SiO2 and ZnCl2/Al2O3 catalysts is described and discussed. Based on earlier observations that supported gold can be an active catalyst for both ethyne hydrochlorination and oxidation reactions, we initially investigated using supported gold as catalysts for the oxychlorination of ethene. However, we found that oxychlorination did not occur in the presence of oxygen and, furthermore, that the gold acted as a poison/inhibitor during the initial reaction period, with the underlying reaction being ethene hydrochlorination. Supported Zn2+ was found to be a very effective catalyst for this reaction. The hydrochlorination of higher alkenes occurred, with high selectivity to a range of relatively complex chlorinated hydrocarbon products at rates of ca. 10-13 mol/(kgcat h).
- Conte, Marco,Davies, Thomas,Carley, Albert F.,Herzing, Andrew A.,Kiely, Christopher J.,Hutchings, Graham J.
-
-
- Kinetics of the reactions of C2H5, n-C 3H7, and n-C4H9 radicals with Cl2 at the temperature range 190-360 K
-
The kinetics of the C2H5 + Cl2, n-C 3H7 + Cl2, and n-C4H9 + Cl2 reactions has been studied at temperatures between 190 and 360 K using laser photolysis/photoionization mass spectrometry. Decays of radical concentrations have been monitored in time-resolved measurements to obtain reaction rate coefficients under pseudo-first-order conditions. The bimolecular rate coefficients of all three reactions are independent of the helium bath gas pressure within the experimental range (0.5-5 Torr) and are found to depend on the temperature as follows (ranges are given in parenthesis): k(C 2H5+ Cl2) = (1.45 ± 0.04) × 10-11 (T/300K)-1-73±0.09 cm3 molecule-1 s-1 (190-359 K), k(n-C3H7 + Cl2) = (1.88 ± 0.06) × 10-11 (T/300 K)-1.57 ± 0.14cm3 molecule-1 s -1 (204-363 K), and k(n-C4H9 + Cl2) = (2.21 ± 0.07) × 10-11 (T/300 K) -238 ± 0.14 cm3 molecule-1 s -1 (202-359 K), with the uncertainties given as one-standard deviations. Estimated overall uncertainties in the measured bimolecular reaction rate coefficients are ±20%. Current results are generally in good agreement with previous experiments. However, one former measurement for the bimolecular rate coefficient of C2H5 + Cl2 reaction, derived at 298 K using the very low pressure reactor method, is significantly lower than obtained in this work and in previous determinations.
- Eskola, Arkke I.,Lozovsky, Vladimir A.,Timonen, Raimo S.
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p. 614 - 619
(2008/09/17)
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- METHOD AND APPARATUS FOR PREPARING VINYL CHLORIDE USING ETHANE AND 1,2-DICHLOROETHANE
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Provided are a method of preparing vinyl chloride including: 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; supplying 1,2-dichloroethane to a pyrolysis reaction region disposed in an upper portion of the pyrolysis reactor; performing a pyrolysis reaction in the pyrolysis reaction region by contacting a product of the ethane chlorination reaction and 1,2-dichloroethane with the solid particles such that the product of the ethane chlorination reaction , the 1,2-dichloroethane and the solid particles rise up at the same time, and depositing coke produced during the pyrolysis reaction on the solid particles; regenerating the solid particles by burning coke deposited on the solid particles in a regeneration reactor; and resupplying the solid particles that collect heat generated by burning coke to the pyrolysis reactor, and an apparatus for preparing the same. When vinyl chloride monomer is prepared using the above-described method, yield is improved, and coke production is inhibited.
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-
Page/Page column 9-12
(2010/11/27)
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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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- Efficient synthesis of 1,2,4-dithiazolidine-3,5-diones [dithiasuccinoyl- amines] from bis(chlorocarbonyl)disulfane plus bis(trimethylsilyl)amines
-
The 1,2,4-dithiazolidine-3,5-dione heterocycle, also referred to as a dithiasuccinoyl (Dts)-amine, serves as a readily removable amino protecting group for building blocks used in syntheses of peptides, glycopeptides, and PNA; it is also useful as a masked isocyanate and (inversely) as a sulfurization reagent for trivalent phosphorus. Bis(chlorocarbonyl)disulfane, the two-sulfur analogue of succinyl chloride, has been envisioned as a reagent for facile single-step elaboration of the heterocycle. However, reactions of bis(chlorocarbonyl)disulfane directly with primary amines fail to yield Dts-amines for reasons that are discussed. Inspired by several precedents from the organosilicon chemistry literature that a trimethylsilyl group may serve as a "large proton," a successful, high-yield preparation of Dts-amines through reactions of bis(chlorocarbonyl)disulfane with bis(trimethylsilyl)amines has been developed. Studies aimed at elucidating mechanistic reasons for these observations are also presented. Copyright
- Barany, Michael J.,Hammer, Robert P.,Merrifield,Barany, George
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p. 508 - 509
(2007/10/03)
-
- N-alkylated thiazolium salts and process for their preparation
-
The present invention relates to N-alkylated thiazolium salts, to a process for their preparation and also to their use as condensation and dehydrating agents.
- -
-
-
- Synthesis and antimicrobial activity of N-(substituted)-N′-[1,2,4, 8,10,11-hexachloro-6-oxido-12H-dibenzo(d,g)(1,3,2)-dioxaphosphocin-6-yl]ureas
-
Substituted dibenzo dioxaphosphocin-6-yl ureas were synthesized by reacting hexachlorophene (4) with different carbamidophosphoric acid dichlorides (3) in the presence of triethylamine in dry toluene at 45-50 °C. Their IR, 1H, 13C and 31P NMR spectral data is discussed. These compounds were found to possess good antimicrobial activity.
- Haranath,Anasuyamma,Vasu Govardhana Reddy,Suresh Reddy
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p. 1001 - 1004
(2007/10/03)
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- METHOD FOR THE COMBINED PRODUCTION OF DIETHYL PHOSPHITE AND ETHYL CHLORIDE
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The invention relates to an improved method for the technical production of diethyl phosphite and ethyl chloride during which the starting material ethanol is mixed with method-specific additives, and this mixture is reacted with phosphorus trichloride. The resulting coupled product ethyl chloride is isolated and is used on the basis of the obtained purity.
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-
Page/Page column 7-8
(2008/06/13)
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- Experimental and theoretical multiple kinetic isotope effects for an SN2 reaction. An attempt to determine transition-state structure and the ability of theoretical methods to predict experimental kinetic isotope effects
-
The secondary α-deuterium, the secondary β-deuterium, the chlorine leaving-group, the nucleophile secondary nitrogen, the nucleophile 12C/13C carbon, and the 11C/14C α-carbon kinetic isotope effects (KIEs) and activation parameters have been measured for the SN2 reaction between tetrabutylammonium cyanide and ethyl chloride in DMSO at 30°C. Then, thirty-nine readily available different theoretical methods, both including and excluding solvent, were used to calculate the structure of the transition state, the activation energy, and the kinetic isotope effects for the reaction. A comparison of the experimental and theoretical results by using semiempirical, ab initio, and density functional theory methods has shown that the density functional methods are most successful in calculating the experimental isotope effects. With two exceptions, including solvent in the calculation does not improve the fit with the experimental KIEs. Finally, none of the transition states and force constants obtained from the theoretical methods was able to predict all six of the KIEs found by experiment. Moreover, none of the calculated transition structures, which are all early and loose, agree with the late (product-like) transition-state structure suggested by interpreting the experimental KIEs.
- Fang, Yao-ren,Gao, Ying,Ryberg, Per,Eriksson, Jonas,Kolodziejska-Huben, Magdalena,Dybala-Defratyka, Agnieszka,Madhavan,Danielsson, Rolf,Paneth, Piotr,Matsson, Olle,Westaway, Kenneth Charles
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p. 2696 - 2709
(2007/10/03)
-
- Process for preparing ethanol
-
The specification discloses a process for the production of ethyl alcohol (ethanol), the process comprising first and second reaction steps operated in tandem. In the first reaction step, ethyl chloride, hydrogen chloride, perchloroethylene and oxygen are reacted in the presence of a catalyst, using ethane as a diluent, to yield reaction products comprising ethyl alcohol and hexachloroethane. Substantially all of the oxygen and hydrogen chloride reactants of this first reaction step are consumed. The ethyl alcohol is isolated from these reaction products. In the second reaction step, the hexachloroethane from the first reaction step is reacted with ethane to produce the ethyl chloride, hydrogen chloride, and perchloroethylene used as reactants in the first reaction step. These reaction products are supplied to the first reaction step, along with any unreacted ethane.
- -
-
-
- Kinetics and mechanism of reaction between N-polyfluorophenylcarbonimidoyl dichlorides and tertiary amines in acetonitrile
-
The reaction of N-polyfluorophenylcarbonimidoyl dichlorides with tertiary amines in acetonitrile afforded chloroamidines R2NC(Cl)=NAr F and alkyl chloride. The precursor of the products is the corresponding quaternary ammonium salt [R3N+C(Cl)=NAr F]-Cl-. The rate of the salt formation is described by a second order equation; however with some amines a saturation effect was observed for the reaction rate with the growing amine concentration. This fact and also the influence of the amine and the substrate structure on the reaction rate suggests that reaction proceeds by addition-elimination mechanism with formation of a tetrahedral intermediate. The latter in the rate-limiting stage undergoes a stereomutation into an intermediate of a configuration favorable for conversion into a quaternary salt.
- Mikhailov,Savelova,Popov,Petrova,Platonov
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p. 1116 - 1124
(2007/10/03)
-
- Hydrodechlorination of 1,2-Dichloroethane over Differently Reduced Pd/SiO2 Catalysts
-
Samples of 5 wt.% Pd/SiO2 catalyst reduced at moderate (400°C) and high temperature (600°C) were investigated in the reaction of 1,2-dichloroethane hydrodechlorination (HDC). The highly reduced catalyst exhibited a higher selectivity towards ethylene, approaching 70% at 300°C, whereas the catalyst reduced at 400°C gave mainly ethane (Sc2H6 ～90% at 300°C). Reduction of Pd/SiO2 at 600°C leads to the formation of palladium suicide. In consequence, incorporation of Si in Pd surface lowers the hydrogenating strength of palladium, contributing to a higher ethylene selectivity. Such a behaviour resembles an analogous situation with Pd modified by Ag. It was shown that the catalysts deactivated rapidly at temperatures between 200 and 300°C. After reaction, much larger amounts of carbon were found in the sample reduced at 400°C. X-ray diffraction studies showed that a considerable part of this carbon was located in the bulk of palladium phase, i.e. forming a PdCx solution.
- Srebowata,Juszczyk,Karpinski
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p. 1841 - 1848
(2007/10/03)
-
- Oxidative alkoxylation of zinc phosphide in alcoholic solutions of copper(II) chloride
-
Oxidative alkoxylation of Zn3P2 with the formation of valuable phosphoric and phosphorous acid esters occurred at a high rate and with a high selectivity in alcoholic solutions of CuCl2 under the action of oxygen at 30-60°C. Depending on the nature of the alcohol, two products were formed, namely, trialkyl phosphates (RO)3PO and dialkyl phosphites (RO)2HPO. Water favored the formation of dialkyl phosphates (RO)2(HO)PO. The kinetics and mechanism of the new catalytic reaction were studied, and the optimal conditions for conducting this reaction were found. The reaction proceeded in a topochemical mode by a separate redox mechanism.
- Dorfman,Ibraimova,Polimbetova
-
-
- Detailed kinetic investigation of the C2H5 + Cl2 reaction and analysis of the reaction of CH3 + Cl2 initiated by H-atom contamination at 298 K and at millitorr pressures
-
The bimolecular reaction: C2H5+Cl2 →4 C2H5Cl+Cl is studied in the very low pressure reactor (VLPR) system at 298 K starting with Cl/C2H6/Cl2 mixtures. Mass conservation is found to be 97±3% for the overall chemical change in the system. From the C2H5Cl product formation kinetics, k4 = (1.05±0.05) · 10-12 cm3/(molecule-s) is derived. Two independent estimates of the A factor gives A4 = 1.3 · 10-12 cm3/(molecule-s). These parameters yield a positive activation energy of 0.13 kcal/mol in contrast with recently reported negative activation energy values. Some side reactions of small extent are initiated by H atom contamination in the system. The measurement of CH3Cl product formed from CH3+Cl2 →11 CH3Cl+Cl gives k11 = (3.4±0.3) · 10-12 cm3/(molecule-s) with an estimated A factor of A11 = 5.0 · 10-12 cm3/(molecules). The source of CH3 radicals is the side reaction H+C2H5 → 2CH3. by Oldenbourg Wissenschaftsverlag, Muenchen.
- Dobis, Otto,Benson, Sidney W.
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p. 283 - 304
(2007/10/03)
-
- Reaction of Trichloro(o-phenylenedioxy)phosphorane with 1,2-Alkadienylphosphonates
-
Trichloro(o-phenylenedioxy)phosphorane reacts with 1,2-alkadienylphosphonates with selective replacement of the alkoxy group in the phosphinoyl moiety, yielding the corresponding 1,2-alkadienylchlorophosphonates and o-phenylene chlorophosphate.
- Khusainova,Garipova,Zyablikova,Cherkasov,Pudovik
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p. 339 - 342
(2007/10/03)
-
- Control of the thermal regime in fast exothermic liquid-phase processes
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Several ways to exert efficient and high-precision control over the thermal regime of very fast chemical processes performed in tubular jet apparatus are discussed.
- Minsker,Malinskaya,Zakharov,Berlin
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p. 1583 - 1587
(2007/10/03)
-
- Mechanoactivated Halogen Substitution Reactions of Alkyl Halides: VI. Halogen Substitution in Ethyl Bromide on the Surface of Mechanically Activated Potassium Chloride
-
Reaction of ethyl bromide with preliminarily activated solid potassium chloride results in quantitative formation of ethyl chloride. Like analogous reactions with methyl and ethyl iodides, the process involves two kinds of active centers on the surface of KCl generated by mechanical treatment. These are vacant sites in the anionic sublattice and divacancies, i.e., anionic vacant sites coupled with cationic vacant sites via Coulomb and elastic interactions. The active centers exert electrophilic assistance to nucleophilic substitution and are regenerated in each act of EtBr conversion into EtCl. Decay of the mono- and divacancies occurs as a result of electron transfer from foreign bromide ion to give F-centers. The rate constants for nucleophilic substitution in ethyl bromide under assistance by mono- and divacancies were estimated. The reactivity of ethyl bromide turned out to be similar to that of ethyl iodide.
- Mitchenko, S. A.,Dadali, Yu. V.
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p. 349 - 353
(2007/10/03)
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- Hydrolytic Etherification of Phenyltrichlorosilane and Structure of Reaction Products
-
Hydrolytic etherification of phenyltrichlorosilane by C1-C4 primary alcohols was studied. The effect of the concentration and nature of alcohol on the structure and properties of oligomeric polyphenyl-alkoxysilanes were examined.
- Kuz'menko, N. Ya.
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p. 516 - 522
(2007/10/03)
-
- Phenyl chloro(thionoformate): A new dealkylating agent of tertiary amines
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Phenyl chloro(thionoformate) reacts rapidly with unhindered tertiary aliphatic amines at 20° to give a thiocarbamate and an alkyl chloride. Dialkylcyclohexylamines react surprisingly rapidly to form predominantly cyclohexene. The thiocarbamates are converted into the secondary amine salt by treatment with dimethyl sulfate, followed by hydrolysis with water. Rates of reaction and alkyl group cleavage selectivity in amines were found to be superior or comparable to those previously reported with chloroformates.
- Milan, David S.,Prager, Rolf H.
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p. 841 - 849
(2007/10/03)
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