- REARRANGEMENT OF 1,3-BROMOCHLOROPROPANE ON ACTIVATED ALUMINA
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The rearrangement of 1,3-bromochloropropane (BCP) on activated alumina was carried out at 160-280 deg C.This reaction proceeded as follows.Br(CH2)3ClBr(CH2)3Br + Cl(CH2)3Cl It was suggested that the acidic sites of alumina played an important role in the rearrangement of halogen atom.
- Shinoda, Kiyonori,Yasuda, Kensei
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Read Online
- METHODS AND SYSTEMS TO FORM PROPYLENE CHLOROHYDRIN AND PROPYLENE OXIDE
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There are provided methods and systems to form propylene chlorohydrin by hydrolysis of 1,2-dichloropropane and to further form propylene oxide from propylene chlorohydrin.
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Paragraph 164
(2019/01/05)
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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 0293
(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 98
(2015/12/04)
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- Propane chlorination over ruthenium oxychloride catalysts
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The gas-phase chlorination of propane over different catalysts, including those containing ruthenium oxychlorides as the active component, has been investigated. The propylene and chlorine-containing product formation selectivities in propane chlorination at 150-450°C in a fixed-bed flow reactor have been determined.
- Testova,Shalygin,Maksimov,Paukshtis,Parmon
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p. 428 - 433
(2015/08/04)
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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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- 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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- MANUFACTURE OF DICHLOROPROPANOL
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Manufacture of dichloropropanol Process for manufacturing dichloropropa nol wherein a glycerol-based product comprising at least one diol containi ng at least 3 carbon atoms other than 1,2- propanediol, is reacted with a chlorinati ng agent, and of products derived from dichloropropanol such as ep ichlorohydrin and epoxy resins. No figure.
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Page/Page column 19-21
(2009/03/07)
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- Determination of the hydrogen-bond basicity of weak and multifunctional bases: The case of lindane (γ-hexachlorocyclohexane)
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We made use of four methods for determining the hydrogen-bond (HB) basicity of lindane (λ-hexachlorocyclohexane): (i) experimental Fourier transform IR measurement of a sum of individual 1:1 equilibrium constants for the formation of 1:1 4-fluorophenol-lindane hydrogen-bonded complexes in CCl4; (ii) calculation of the overall HB basicity from octanol-water partition coefficients; (iii) correlation of the HB basicity of chloroalkanes with the electrostatic potentials around chlorine atoms; and (iv) correlation of the HB basicity of chloroalkanes with the computed enthalpy of their complexes with hydrogen fluoride. It is consistently found that lindane remains a weak HB base because multifunctionality cannot fully compensate for the electron-withdrawing inductive effects that chlorine atoms exert over one another. Actually, only five chlorine atoms behave as HB acceptors, one axial chlorine being deactivated by inductive effects. Stereoelectronic effects lead to the formation of three-centered hydrogen bonds. Copyright
- Ouvrard, Carole,Lucon, Maryvonne,Graton, Jerome,Berthelot, Michel,Laurence, Christian
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- Flash vacuum pyrolysis over magnesium. Part 1 - Pyrolysis of benzylic, other aryl/alkyl and aliphatic halides
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Flash vacuum pyrolysis over a bed of freshly sublimed magnesium on glass wool results in efficient coupling of benzyl halides to give the corresponding bibenzyls. Where an ortho halogen substituent is present further dehalogenation gives some dihydroanthracene and anthracene. Efficient coupling is also observed for halomethylnaphthalenes and halodiphenylmethanes while chlorotriphenylmethane gives 4,4′-bis(diphenylmethyl)biphenyl. By using α,α′-dihalo-o-xylenes, benzocyclobutenes are obtained in good yield, while the isomeric α,α′-dihalo-p-xylenes give a range of high thermal stability polymers by polymerisation of the initially formed p-xylylenes. Other haloalkylbenzenes undergo largely dehydrohalogenation where this is possible, in some cases resulting in cyclisation. Deoxygenation is also observed with haloalkyl phenyl ketones to give phenylalkynes as well as other products. With simple alkyl halides there is efficient elimination of HCl or HBr to give alkenes. For aliphatic dihalides this also occurs to give dienes but there is also cyclisation to give cycloalkanes and dehalogenation with hydrogen atom transfer to give alkenes in some cases. For 5-bromopent-1-ene the products are those expected from a radical pathway but for 6-bromohex-1-ene they are clearly not. For 2,2-dichloropropane and 1,1-dichloropropane elimination of HCl occurs but for 1,1-dichlorobutane, -pentane and -hexane partial hydrolysis followed by elimination of HCl gives E, E-, E,Z- and Z,Z- isomers of the dialk-1-enyl ethers and fully assigned 13C NMR data are presented for these. With 6-chlorohex-1-yne and 7-chlorohept-1-yne there is cyclisation to give methylenecycloalkanes and -cycloalkynes. The behaviour of 1,2-dibromocyclohexane and 1,2-dichlorocyclooctane under these conditions is also examined. Various pieces of evidence are presented that suggest that these processes do not involve generation of free gas-phase radicals but rather surface-adsorbed organometallic species.
- Aitken, R. Alan,Hodgson, Philip K.G.,Morrison, John J.,Oyewale, Adebayo O.
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p. 402 - 415
(2007/10/03)
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- Pressure dependence of the reaction Cl + C3H6
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The rate constant for the reaction Cl + C3H6 (k1) has been measured relative to that of Cl + C2H6 over the range 0.3-700 Torr in N2 at 298 K. UV irradiation was used to generate Cl atoms in mixtures of C3H6, C2H6, Cl2, and N2 in two different reactors using FTIR or GC analysis. The yields of the two major products, allyl chloride (3-C3H5Cl) and 1,2-dichloropropane were measured. k1 decreases by a factor of 5 between 700 and 1 Torr. Below 1 Torr, the rate constant becomes independent of pressure. The results indicate that k1 is a composite of three reaction channels, each having a different pressure dependence. Measurement of the yield of 1,2-dichloropropane, the final product formed from the addition of Cl to C3H6, at each pressure allows a determination of the rate constant (k1a) for the addition of Cl to C3H6. Assuming a typical center broadening factor (Fc = 0.6), the high- and low-pressure limiting constants are calculated to be k1a(∞) = (2.7 ± 0.4) × 10-10 cm3 molecule-1 s-1 and k1a(0) = (4.0 ± 0.4) × 10-28 cm6 molecule-2 s-1. The pressure dependence of the yield of 3-C3H5Cl indicates that the allyl radical is likely formed by both abstraction and addition-elimination channels. The rate constant of the abstraction reaction from the methyl radical in C3H6 is (2.3 ± 0.3) × 10-11 cm3 molecule-1 s-1. At pressures below 10 Torr, the rate constant for formation of the allyl radical increases by 50%, and this is ascribed to an addition-elimination process. Relative rate constant ratios were also measured for Cl atom reactions with allyl chloride (k6) and 1,2-dichloropropane (k7) relative to C3H6, C2H5Cl, or CH3Cl to correct the product yield experiments for secondary consumption. The observed values of k6/k1 are 0.75 for total pressures of 10-700 Torr, 0.44 at 1 Torr, and 0.33 at 0.4 Torr. On the basis of the relative rate measurements k7 = (3.9 ± 0.6) × 10-12 cm3 molecule-1 s-1 over the range 1-700 Torr.
- Kaiser,Wallington
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p. 9788 - 9793
(2007/10/03)
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- Reaction of Organic Compounds with the System SF4-HF-Halogenating Agent. XII. Reactions of Aliphatic Alcohols with the System SF4-HF-Cl2
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Reactions of aliphatic alcohols with the system SF4-HF-Cl2 are investigated. Chlorofluoroalkanes are shown to be produced in high yields when the double bond formation occurs under mild conditions.
- Kunshenko,Ostanin,Yagupol'skii
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p. 1420 - 1423
(2007/10/03)
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- Oxychlorination and combustion of propene on fly-ash. Formation of chlorinated benzenes, dibenzodioxines and mono- and dibenzofurans
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Heterogenous gas phase reactions of propene on fly ash in the presence of hydrochloric acid and air between 300-580 deg C have been investigated. At mild conditions only the formation of polychlorinated C1, C2 and C3 species takes place. At the high tempe
- Jarmohamed, W.,Mulder, P.
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p. 1911 - 1918
(2007/10/03)
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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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p. 1288 - 1293
(2007/10/02)
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- REACTION OF ORGANIC COMPOUNDS WITH SF4-HF-HALOGENATING SYSTEM VII. REACTIONS OF OLEFINS WITH THE SF4-HF-Cl2(Br2) SYSTEM
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Under the influence of the SF4-HF-Cl2(Br2) system halogen-containing olefins undergo conjugate halogenofluorination.It was shown for the case of (Z)- and (E)- 1,2-dichloroethenes that these reactions take place anti-stereospecifically through the formation of the bromonium ions.The accumulation of chlorine atoms in the olefin molecule hinders electrophilic addition of stoichiometric equivalents of ClF and BrF at the double bond.The SF4-HF-Br2 system is an effective agent for substitutive fluorination of organic compounds containing bromine.Only the bromine atoms situated at the secondary carbon atom are substituted by fluorine.
- Kunshenko, B. V.,Mokhamed, Nagib Mukhtar,Omarov, V. O.,Muratov, N. N.,Yagupol'skii, L. M.
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p. 511 - 518
(2007/10/02)
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- COMPETITION BETWEEN n,?- AND n,?-ORBITAL INTERACTIONS IN CHLORINATED ETHERS R-O-CHClR1
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Using the AM-1 method, we have studied CH2=CH-O-CHClR1 molecules (R1 = H, Me).We have shown that the sc conformation with respect to the Csp3-O bond is preferred.We have systematized the 35Cl NOR data on the degree of manifestation of the generalized anomeric effect in R-OCHClR1 2C(=O)> molecules.We have established that enhancement of n,? conjugation in the R-O fragment leads to weakening of the n,? interaction in the O-C-Cl triad.
- Bredikhin, A. A.,Kirillovich, V. A.,Safin, I. A.,Vereshchagin, A. N.
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p. 2185 - 2189
(2007/10/02)
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- ROLE OF INTERMOLECULAR INTERACTIONS IN THE SELECTIVE EFECT OF THE MEDIUM ON FREE-RADICAL CHLORINATION
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The effect of noncomplexing solvents on the selectivity of the free-radical chlorination of 2-chloropropane was studied.It was shown that the relative reactivity of C-H bonds in 2-chloropropane correlates with the solubility parameter and with the Kirkwood function.The obtained data are treated as a result of solvation of the chlorine atoms in solution.It was concluded that it is necessary to include the contribution from the substrates to the overall effect of the medium during interpretation of the selective action of the complexing solvents.
- Aver'yanow, V. A.,Golubev, V. E.,Semenov, A. O.,Kostylev, I. M.
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p. 1759 - 1764
(2007/10/02)
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- Substituted imidazolones having herbicidal activity
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The invention relates to novel herbicidally active compounds of formula I STR1 in which B represents an imidazolone of formula STR2 or A and B together represent a fused imidazolone of formula STR3 and the radicals X, R1, R2 and A in addition have the meanings given in the text and R3 represents C1 -C4 -alkyl and R4 represents a methyl or ethyl group subtituted by from 1 to 5 fluorine atoms, processes for the preparation thereof, compositions containing compounds of formula I, methods of controlling weeds, and novel intermediates for the preparation of the compounds of formula I.
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- THERMAL TRANSFORMATIONS OF 1,2-CHLOROHYDRINS
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The composition of the products and the kinetic parameters were determined for the liquid-phase thermolysis of 2-chloro-1-propanol at 130-160 deg C and of 1,3-dichloro-2-propanol and 2,3-dichloro-1-propanol at 180-200 deg C.The intramolecular dehydrochlorination of the 1,2-chlorohydrins is based on a process of the E1 type with the formation of an enol, which rearranges to the carbonyl compound according to the El'tekov rule; the isomerization of 1,2-chlorohydrins catalyzed by hydrogen chloride and their reaction with hydrogen chloride take place through the formation of a chloronium cation, which is attacked in the first case by a water molecule and in the second by the chloride ion.
- Zil'berman, I. E.,Kolesnikov, V. A.,Danov, S. M.,Efremov, R. V.
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p. 542 - 547
(2007/10/02)
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- MECHANISMS OF FREE-RADICAL REACTIONS. XXIV. QUANTITATIVE DESCRIPTION OF THE POLAR EFFECTS OF SUBSTITUENTS ON THE KINETICS OF THE FREE-RADICAL CHLORINATION OF ALIPHATIC COMPOUNDS BY N-CHLOROPIPERIDINE
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The free-radical chlorination of 1-substituted alkanes with electron-withdrawing substituents by N-chloropiperidine in trifluoroacetic acid was studied by the method of competing reactions, and the relative rate constants were obtained for all positions of the substrates.The data on the position selectivity can be described satisfactorily by means of an electrostatic model of the polar effect of the substituent, calculated according to the Kirkwood-Westheimer equation.The obtained characteristics of the electrostatic effect can be successfully applied to calculation of the substrate selectivity and the intermolecular relative rate constants for all the positions, beginning with the third.The Taft equation is unsuitable for description of the effect of substituents on the reaction rate.
- Dneprovskii, A. S.,Mil'tsov, S. A.,Arbuzov, P. V.
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p. 1826 - 1835
(2007/10/02)
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- Process for cleaving aliphatic ether compounds
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Aliphatic ether compounds are cleaved by reacting them with acid halides in the presence of a Lewis acid catalyst. The aliphatic ethers have at least one halogen atom in a beta-position to the oxygen atom. The corresponding esters and halides having the unreacted beta-halogen atom(s) are produced.
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- Adsorption of Reagent on the Surface of Copper Chloride Catalysts for the Oxidative Chlorination of Propene
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We have studied the adsorption of propene, HCl, and oxygen on the surface of the oxidative chlorination catalysts CuCl2-α-Al2O3, CuCl-α-Al2O3, and CuCl2.The effect of the previous sorption of some sorbates on the sorption of others has been established.It has been shown experimentally that Cu(I) chloride, detected by X-ray diffraction, can catalyse the main reactions of Cu(II) chloride.
- Potapov, A. M.,Kolesnikov, I. M.,Rysaev, U. Sh.,Sergeev, V. N.
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p. 1732 - 1735
(2007/10/02)
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- Three Component Reactions. XVII. Terminal Reactive Oligooxyethylene Structures from Alkenes, Chlorine and O-Nucleophiles and Their Transformation into Oxathiaalkanes
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The reaction of alkenes, chlorine and oxirane, dioxane, ethyleneglycole, oligoethyleneglycoles, the monoethers of oligoethyleneglycoles, ethylene chlorohydrine or α-hydro-ω-chloro-oligooxyethylenes leads to compounds 6-9, which contain mono or oligoether functions and one or two reactive terminal chlorine atoms.Oxathiaalkanes (10 and 12) were obtained in the reaction of such compounds with sodium mercaptides.
- Beger, J.,Poeschmann, C.,Shabanov, A. L.,Gurbanov, P. A.
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p. 996 - 1007
(2007/10/02)
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- THE LONG-RANGE ACTION OF THE POLAR EFFECT OF SUBSTITUENTS ON THE ABSTRACTION OF HYDROGEN IN FREE-RADICAL CHLORINATION PROCESSES
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The free-radical chlorination of 1-chloroalkanes between C3 and C6 at 263 deg K was studied under conditions with wide variation in the concentrations of the substrates in benzene.By analysis of the products from chlorination of the pure substrates it was shown that the deactivating effect of the polar substituent does not extend beyond the third carbon atom and is mainly determined by the inductive effect.In the transition to an aromatic solvent the deactivating effect on the substituent extends to the fourth carbon atom.The results are substantiated in terms of a contribution from dipole-dipole interaction between the substituent and the polar form of the transition state to the polar effect of the substituents.
- Aver'yanov, V. A.,Ruban, S. G.,Klykova, M. B.,Golubev, V. E.
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p. 435 - 439
(2007/10/02)
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- EFFECT OF THE COMPLEX-FORMING CHARACTERISTICS OF AROMATIC SOLVENTS ON THE SELECTIVITY OF FREE-RADICAL CHLORINATION. CHLORINATION OF 2-CHLOROPROPANE
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During investigation of the effect of six solvents of aromatic nature on the selectivity of the free-radical chlorination of 2-chloropropane it was found that the / ratio insceases with increase in the content of the solvent in the reaction mixture and with decrease in the temperature.The obtained data were interpreted by a mechanism involving the formation of ? complexes between the chlorine atoms and the aromatic molecules ArHCl. as particles responsible for the selective effect of the solvents.On the basis of the adopted mechanism an equation was obtained for the selectivity of the process with parameters reflecting the relative reactivities of the various C-H bonds in the 2-chloropropane during their reaction with the chlorine atoms and the ArHCl. complexes.The differences in the activation energies of the competing reactions of the C-H bonds with ArHCl. correlate with the electron-donating characteristics of the solvent molecules.
- Aver'yanov, V. A.,Ruban, S. G.
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p. 1119 - 1125
(2007/10/02)
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- THERMAL CONVERSIONS OF alpha -PROPYLENE CHLOROHYDRIN.
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The purpose of the authors' work was to determine the principal relationships of thermal decomposition of anhydrous PCH in the liquid phase. Preliminary experiments showed that appreciable decomposition of PCH begins only at 130 degree . Therefore thermal conversions of PCH were studied at higher temperatures than in the case of ethylene chlorohydrin in the range 140-170 degree . It is shown that acetone, 1-(1-chloroisopropoxy)-2-propanol, 2-chloro-1-propanol, hydrogen chloride, and 1,2-dichloropropane are formed during liquid-phase thermal decomposition of 1-chloro-2-propanol in the temperature range 140-170 degree . Isomerization of 1-chloro-2-propanol to 2-chloro-1-propanol is accelerated by the hydrogen chloride formed during its thermal decomposition.
- Kolesnikov,Zil'berman,Danov,Efremov
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p. 2384 - 2386
(2007/10/02)
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- NONAQUEOUS SOLUTION OF HYPOCHLOROUS ACID AND CHLOROHYDRINATION REACTIONS OF CERTAIN LOWER ALKENES.
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A study was made of the problems of preparing stable, highly concentrated nonaqueous solutions of hypochlorous acid and carrying out chlorohydrination reactions in them. The results on the chlorohydrination of alpha -alkenes showed that, in principle, it is possible and advisable to use solutions of hypochlorous acid in organic solvents, in particular, aliphatic and alicyclic ketones, ethyl acetate and tributyl phosphate. The use of organic solvents noticeably improves the stability of HOCl, so that the working concentrations of the acid can be increased, and the chlorohydrination reaction products can be more easily isolated.
- Bikbulatov,Valitov,Gromova,Stepanova,Martynova
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p. 2314 - 2317
(2007/10/02)
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- EFFECT OF ACETIC ACID ON THE SELECTIVITY OF FREE-RADICAL CHLORINATION PROCESSES
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The effect of acetic acid on the selectivity of the chlorination of 1,1-dichloroethane and 2-chloropropane in the range of temperatures between -10 and 60 deg C was investigated.It was shown that increase in the acetic concentration leads to a decrease in the amount of products from chlorination at the chlorine-substituted position, and in the region of high solvent concentrations the selectivity of chlorination becomes insensitive to temperature.The results are discussed from the standpoint of the increase in the steric and energy hindrances during attack at the more substituted positions due to the solvatation of the chlorine atoms and the substrate molecules.
- Aver'yanov, V. A.,Ruban, S. G.
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p. 2267 - 2269
(2007/10/02)
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- Three Component Reactions. XVI. Halogenation of Alk-1-enes in the Presence of Ethylene Oxide and Propylene Oxide
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The products of the chlorination of alk-1-enes in the presence of ethylene oxide and propylene oxide were investigated in relation to products of the chlorination in the presence of corresponding chloroalcohols 4 and 5.Isomers dominating in the Markovnikov orientation were found in all cases.Two of the three pairs of diastereomeric bischloropropylethers expected for the chlorination of propene in the presence of propylene oxide were identified by capillar GLC and 13C n.m.r. spectroscopy.
- Beger, J.,Schiefer, H.,Scheller, D.
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p. 719 - 728
(2007/10/02)
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- Thermocatalytic Reactions of Bromochloropropanes
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The thermodynamic characteristics of the disproportionation and dehydrohalogenation reactions of halogenopropanes (1,2- and 2,2-isomers) have been calculated and tested experimentally.The legitimacy of using the incremental method for the calculation of the thermodynamic functions of bromochloropropanes has been demonstrated.An increase of the length of the hydrocarbon group and the geminal positions of the halogen atoms in the molecule greatly reduce the probability of disproportionation reactions.
- Levanova, S. V.,Rodova, R. M.,Tereshkina, T. P.,Zabrodina, T. I.
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p. 1142 - 1146
(2007/10/02)
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- Process for making vicinal epoxides
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Vicinal epoxides are prepared by decomposition of β-haloalkyl carbonates or bis(β-haloalkyl) carbonates in the presence of a complex of an alkali metal halide and a monomeric or polymeric chelating agent comprising an element of group V of the Periodic Table at a temperature from about 25° C. to about 250° C.
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- EFFECT OF o-DICHLOROBENZENE ON SELECTIVITY IN THE CHLORINATION OF CHLOROPROPANES
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The competing chlorination of chloropropanes in o-dichlorobenzene was investigated over a wide range of temperatures and o-dichlorobenzene concentrations.The selective action of o-dichlorobenzene is interpreted by a mechanism involving attack on the C - H bond in the chloropropanes by free chlorine atoms and by aromatic ? complexes ArH -> Cl.Mathematical models of the selectivity of the processes based on the proposed mechanism were obtained.The parameters of the models reflect the relative reactivity of the C - H bonds during chlorination by chlorine atoms and ArH-> Cl complexes and also the capacity of the solvent for complex formation with chlorine atoms.
- Aver'yanov, V. A.,Zarytovskii, V. M.,Shvets, V. F.
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p. 1487 - 1491
(2007/10/02)
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- The Dehydrochlorination of gem-Dichloroalkane and the Formation of Dienes from the Reactions of Butenes and Cyclohexene with Chlorine through Molten Salt
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The dehydrochlorination of 1,1-dichloropropane and 1,1-dichloro-3-methylbutane was carried out over molten salt catalysts (mainly ZnCl2-containing melts) using a conventional flow system.The cis/trans ratio (1.8) of the resulting olefins from 1,1-dichlorobutane was found to stand between the ratio (1.4) with 1,1-dichloro-3-methylbutane and the ratio (2.2) with 1,1-dichloropropane; this can be explained by considering the stereochemistry of the adsorbed carbonium ions.The detailed results of the reactions of three butene isomers with chlorine through molten salts were presented.The selective formation of butadiene was explained in terms of the thermally assisted attack of chlorine in the allylic positions of butene, followed by the 1,2- or 1,4-elimination of HCl from chlorobutenes, a process which is strongly assisted by the ZnCl2-containing melts.The reaction of 2-methyl-2-butene and cyclohexene with chlorine through molten salts was also undertaken.The addition of Zn powder to ZnCl2 melts in advance was found to improve the selectivity for the formation of isoprene and cyclohexadiene.Because the HCl evolved reacts instantly with Zn powder to afford ZnCl2 and hydrogen, Zn powder substantially prohibits the addition of HCl to dienes yielding chlorobutenes and chlorocyclohexenes.
- Kikkawa, Shoichi,Nomura, Masakatsu,Shimizu, Michimasa
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p. 2586 - 2591
(2007/10/02)
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