1-chloropropane Research Articles

Dechlorination of Concentrated Monochloroalkanes under Various Hydrothermal Conditions

Fundamental reaction behavior in dechlorination of concentrated monochloroalkanes (methyl, ethyl, n-propyl, and iso-propyl chloride), whose concentrations were set at as high as 15–20 times the solubility at room temperature, was investigated at various hydrothermal conditions under a saturated vapor pressure up to 380°C. The optimum conditions for the dechlorination treatment and solvent effects on the reactions have been discussed based on the results obtained under specific conditions of temperature, reaction time, stirring rate, solvent states (e.g., volume ratio of chloride to solvent, concentration of additive alkali or alcohol, filling ratio of solution in a vessel) on the dechlorination ratio. All the chlorides studied in the present work were easily dechlorinated by hydrolysis, and the alkyl groups were preserved under hydrothermal conditions in the “subcritical” region. These results indicate the optimum conditions for hydrothermal dechlorination and that the products can be controlled in the yield and ether formation by the concentration of the additives in the solvent.

Nucleophilic Substitution in Radicals Derived from Isopropyl Chloride

Nucleophilic Substitution in Radicals Derived from Isopropyl Chloride

Putting Isomers in Their Place

CHEMISTRY Normally the isomers of chemical compounds are defined by different sets of covalent bonds or by different stereochemical arrangements at chiral centers. Shivanyuk and Rebek demonstrate a further type of isomerization by trapping guest molecules in molecular capsules. Three molecules of chloroform (CHCl3; 74 cubic angstroms) or isopropyl chloride [ClCH(CH3)2; 73 cubic angstroms] fit snugly in a 420 cubic angstrom cavity formed by two cavitand molecules. Nuclear magnetic resonance studies show that all six possible arrangements of three guest molecules can be identified. These structures are dynamic, so they can start with the complex containing three isopropyl chloride molecules and titrate in chloroform to create the other isomers. — PDS Angew. Chem. Int. Ed . 42 , 684 (2003).

Direct synthesis of organodichlorosilanes by the reaction of metallic silicon, hydrogen chloride and alkene/alkyne and by the reaction of metallic silicon and alkyl chloride

Dichloroethylsilane was synthesized by the reaction of metallic silicon, hydrogen chloride and ethylene using copper(I) chloride as the catalyst, the silicon conversion and the selectivity for dichloroethylsilane being 36 and 47%, respectively. At a lower reaction temperature or at a higher ratio of ethylene∶hydrogen chloride a higher selectivity was obtained, however the silicon conversion was lower. The silicon–carbon bond formation is caused by the reaction of a surface silylene intermediate with ethylene. The reaction with propylene in place of ethylene gave dichloroisopropylsilane (22% selectivity) and dichloro-n-propyl-silane (8% selectivity) together with chlorosilanes. A part of the dichloroisopropylsilane is formed by the reaction of silicon, hydrogen chloride and isopropyl chloride formed by hydrochlorination of propylene. Use of acetylene instead of alkenes resulted in dichlorovinylsilane formation with a 34% selectivity. Alkyldichlorosilanes were also produced directly from silicon with alkyl chlorides, propyl and butyl chlorides. During the reaction the alkyl chloride is dehydrochlorinated over the surface of copper originating from the catalyst to afford hydrogen chloride and alkene. The hydrogen chloride formed participates in the formation of the silicon–hydrogen bond in alkyldichlorosilane, and the reaction of silicon, hydrogen chloride and alkene also causes alkyldichlorosilane formation. The reaction with isopropyl chloride gave a very high selectivity (85%) for dichloroisopropylsilane, the silicon conversion being 86%. p

Synthesis and resolution of benzylisopropylphenylphosphine, a monodentate P-chiral ligand

The synthesis of benzylisopropylphenylphosphine by reaction between the benzylphenylphosphide anion and isopropyl chloride and its subsequent resolution by means of an optically active palladium metallacycle is reported. The synthesis of the organometallic complex [Pd(η 3-2-MeC 3H 4)Cl(PBn i PrPh)] is also described, as well as the assignment of the absolute configuration of the coordinated phosphine by mono- and bidimensional proton NMR spectra, using the homochiral palladacycle as a reference point. In order to estimate the height of the energy barrier corresponding to the rotation of the phosphine ligand around the PdP bond, several calculations were performed at the semiempirical PM3(tm) level.

Temperature effect on nonhydrolytic foaming process

This paper describes the effect of temperature on the formation of nonhydrolytic alumina foams. The foams are generated by heat treatment of crystals of the aluminum chloride isopropyl ether complex [AlCl3(Pri2O)], with the release of isopropyl chloride (PriCl). The chlorine content in the foams was determined by titration, and their weight loss during sintering was measured by thermogravimetric and differential thermal analysis. Based on these measurements, the condensation degree (CD) in the foams was modeled. The foaming time ranged from several minutes at 70 °C to several seconds at 160 °C. It was found that the chlorine-to-aluminum ratio of the foam (Cl/Al) decreased from 1.79 at 70 °C to 1.56 at 160 °C. Thermogravimetric analysis data confirm that the smaller Cl content gives rise to a smaller weight loss during thermal decomposition, consistent with a higher CD in the foams created at higher temperatures. Finally, about 80% of the PriCl produced during complex decomposition and subsequent –Al–O–Al– condensation reactions is lost during foaming.

Pulsed laser powered homogenous pyrolysis for reaction kinetics studies: Probe laser measurement of reaction time and temperature

Pulsed laser powered homogeneous pyrolysis (LPHP) is a technique which can be used to measure rate parameters for purely homogeneous unimolecular decomposition reactions at high temperatures (600–1500 K). The reaction temperature in pulsed LPHP may be obtained from the speed of sound in the reacting gas, which may be measured by observing the thermal lens effect of the gas on a probe laser beam. The reaction time may be obtained directly from the thermal lens measurements. In this work experiments were performed using ethyl acetate (EtAc) and isopropyl chloride (2-ClPr), two reactants whose unimolecular decomposition rate parameters are well established. This allowed us to assess the accuracy and precision attainable with this technique. Pulsed LPHP proved capable of providing rate parameters in good agreement with those in the literature. The results for which the measured activation energies were closest to the literature values gave the temperature dependence of the rate constants as log(kEtAc) = (12.0 ± 0.9) − 47.7 ± 4.4(kcal/mol)/2.303RT and log(k2-ClPr) = (13.3 ± 1.0) − 50.8 ± 4.8(kcal/mol)/2.303RT. These may be compared with the literature recommendations, log(kEtAc) = 12.6 − 48.0(kcal/mol)/2.303RT and log(k2-ClPr) = 13.6 − 51.1(kcal/mol)/2.303RT. In all cases the measured rate parameters agreed with the recommended values to within the error limits of the measured values. Potential sources of error in the temperature measurement and the kinetic parameters are explored. The expected accuracy of the experiments is assessed, and possible improvements in the experiment are suggested. © 1996 John Wiley & Sons, Inc.

Effect of Phospho-Halogenated Polyethcr Polyol on Fire Behaviour of Rigid Polyurethane Foams Blown with Various Agents

The substitution of CFC-11 with blowing agents with low environmental impact, for the production of PU thermal insulating materials, implies the variation of several properties of the material. The worsening of fire behaviour of material, based on Ixol B 251, with flammable blowing agents (HCFC-141b, 2-chloro propane and n-pentane) can be reduced by modifying the formulation, i.e. by increasing the amount of flame retardants. The results of the Oxygen Index test were compared with the data obtained from the ISO 3582, DIN 4102 - B2 and UNI 9177 test and gave a good correlation. The initial thermal conductivity of the various foams is strictly linked with the thermal conductivity of the gas phase and increases with the new blowing agents and particularly in the case of n-pentane reaches values which are about 20% higher than that of foams blown with CFC-11. Hydrocarbon type blowing agents do not change significantly the mechanical properties of the materials; small variations in mechanical properties with HCFC-141b should be attributed to the solvent action of the compound on the polymer matrix.

ChemInform Abstract: Unusual Course of the Alkylation of a Aluminum Chloride‐Diphenylchlorophosphine‐Hydrogen Chloride Complex on Reaction with Benzene and Isopropyl Chloride.

AbstractThe complex (I) reacts with benzene (II) and isopropyl chloride (III) to produce the phosphine oxides (IV) and (V).

Reactive scattering from double minimum potentials: Li+ catalyzed elimination reactions of alkyl halides

We present a study of the dehydrohalogenation reactions of Li+ with isopropyl chloride (IPC), n-propyl chloride (NPC), and isopropyl bromide (IPB) over the collision energy range from 0.6 to 1.7 eV. Full differential cross sections at collision energies up to 1.2 eV show increasing asymmetry in the angular distributions as a function of initial collision energy and suggest that the reactions take place on a time scale of 0.2 ps. The observation of Li+ nonreactively ejected from the initial encounter complex formed by approaching reactants is consistent with a double minimum reaction coordinate and a comparison of the nonreactive flux with the flux for elimination products allows an estimate of the heights of intermediate isomerization barriers separating the wells on the potential surface. The barrier heights are in the order IPC<IPB<NPC, consistent with a transition state at the isomerization barrier in which a significant charge has developed on the carbon attached to the halogen. The kinetic energy distributions for Li+(HX) and Li+(C3H6) products and nonreactively scattered Li+ are in reasonable agreement with phase space theory calculations which include all product vibrational modes. The energy dependence of the Li+(HX)/Li+(C3H6) branching ratio can be accounted for quantitatively by statistical calculations which include the increasing importance of dissociation of the products with increasing collision energy. The discrepancy between the statistical recoil energy distributions and apparent complex lifetimes several orders of magnitude shorter than the predictions of RRKM theory can be understood in terms of incomplete transfer of energy from the incident Li+ to the internal degrees of freedom of the initial encounter complex, resulting in a density of complex states much lower than statistical.

Reactive scattering from double-minimum potentials

We present a crossed-beam study of the elimination reactions of Li+ with t-butyl alcohol (TBA), isopropyl chloride (IPC), n-propyl chloride (NPC), and isopropyl bromide (IPB) over the collision energy range 0.6–2.5 eV. Full differential cross-sections at collision energies up to 1.2 eV show increasing asymmetry in the angular distributions as a function of initial collision energy and suggest that the reactions take place on a timescale of 0.2–0.5 ps. The observation of Li+ being non-reactively ejected from the initial encounter complex formed by approaching reactants is consistent with a double-minimum reaction coordinate and a comparison of the non-reactive flux with the flux for elimination products allows an estimate of the heights of intermediate isomerization barriers separating the wells on the potential surface. The kinetic energy distributions for Li+(HX) and Li+(olefin) products and non-reactively scattered Li+ are in reasonable agreement with phase-space theory calculations which include all product vibrational modes. The energy dependence of the Li+(HX)/Li+(olefin) branching ratio can be accounted for with statistical calculations which include product dissociation. The discrepancy between the statistical recoil energy distributions and apparent complex lifetimes several orders of magnitude shorter than the predictions of RRKM theory can be understood in terms of the specific dynamics of passage from the crest of the isomerization barrier to the second well of the potential surface and the apparent failure of the system to re-establish microcanonical equilibrium in that well.

Telechele des methylpropens durch kationische polymerisation

AbstractAromatic and aliphatic hydrocarbons containing isopropyl chloride end groups in combination with boron trichloride are effective initiator systems for the cationic polymerization of methyl propene. The mathematical modelling of the proposed reaction mechanism leads to rate constants for initiation, propagation and termination which allows a good fit with experimental results. Recycling experiments have clearly shown that it is possible to reuse the coinitiator boron trichloride and the solvent dichloromethane without effecting the quality of the products.

ChemInform Abstract: RAMAN STUDY OF VIBRATIONAL DEPHASING IN HALOALKANES

The Raman spectra of the carbon–halogen stretching mode was measured as a function of temperature in the five liquids: ethyl bromide, isopropyl chloride and bromide, and t‐butyl chloride and bromide. The derived isotropic (vibrational relaxation) correlation times showed a very clear trend. The magnitude of τiso was quite similar in both chloroalkanes (in the range from 1.2 to 1.5 ps), whereas, the values in all three bromoalkanes were virtually superposable and markedly longer (1.8–2.1 ps) than in the chloro compounds. These results, together with those from earlier studies on methyl iodide, provide evidence that vibrational dephasing efficiencies (τ−1iso) of the C–X mode in haloalkanes vary in the order Cl≳Br≳I. It was further observed that, in contrast to the rather unusual temperature dependence of vibrational relaxation in methyl iodide, τiso either remained approximately constant or decreased with temperature in the compounds studied here. Modulation times calculated from the Kubo expression were fo...

Synthèse de la diméthyl‐4,4‐dihydrofuranedione‐2,3

Abstract4,4‐Dimethyl‐dihydro‐2,3‐furanedione (4), an intermediate in the synthesis of (+)‐D‐pantothenic acid, is obtained in good yield from readily available substances such as isopropyl chloride, diethyl oxalate and formaldehyde, without oxidative conditions.

Raman study of vibrational dephasing in haloalkanes

The Raman spectra of the carbon–halogen stretching mode was measured as a function of temperature in the five liquids: ethyl bromide, isopropyl chloride and bromide, and t-butyl chloride and bromide. The derived isotropic (vibrational relaxation) correlation times showed a very clear trend. The magnitude of τiso was quite similar in both chloroalkanes (in the range from 1.2 to 1.5 ps), whereas, the values in all three bromoalkanes were virtually superposable and markedly longer (1.8–2.1 ps) than in the chloro compounds. These results, together with those from earlier studies on methyl iodide, provide evidence that vibrational dephasing efficiencies (τ−1iso) of the C–X mode in haloalkanes vary in the order Cl≳Br≳I. It was further observed that, in contrast to the rather unusual temperature dependence of vibrational relaxation in methyl iodide, τiso either remained approximately constant or decreased with temperature in the compounds studied here. Modulation times calculated from the Kubo expression were found to be significantly longer (approximately 1 ps) in the isopropyl halides than in the t-butyl compounds, where τm’s were of the same magnitude as Enskog collision times. Vibrational dephasing times calculated from the Fischer–Laubereau isolated binary collision model were of the same order of magnitude but longer than the experimental correlation times.

Étude de l'extraction des acides organiques urinaires : Étape préalable à leur séparation en chromatographie en phase gazeuse

Study of the extraction of organic acids from urine. Preliminary step to their gas chromatographic separation Ten organic acids are extracted from urine. Two extraction methods are used: anion exchange on DEAE-Sephadex columns, and orgnanic solvent extraction with five different solvents: diethyl ether, ethyl acetate, isopropyl chloride, light petroleum, and tetrahydrofuran. In order to quantify the extractions, the corresponding 14C-labeled acids are added to standard acid solutions and extraction rates are measured by a liqiud scintillation counting system. The results show that: (1) The efficiency of anion exchange is generally good for all tested acids. (2) The extraction efficiency is not identical for the different solvents, one solvent being more efficient for a certain acid than another: tetrahydrofuran, which is generally a good solvent, is too hygroscopic to be usable. Isopropyl chloride and light petroleum are too specific with the most apolar molecules. Ethyl acetate and diethyl ether are similar and usable because of their acceptable solubilisation power as to the most polar molecules, their good solubilisation reproducibility and their readiness of use. (3) The solvent extraction method is not as time-consuming as the anion-exchange method which generally requires lengthy elution and extraction.

正誤訂正

正誤訂正

ポリエチレングリコールジアルキルエーテルを溶媒とした，カリウム３‐アミノフェノキシドと塩化イソプロピルとの反応

The effects of polyethyleneglycol dialkyl ethers as solvents in the reaction of potassium 3-aminophenoxide with isopropyl chloride were studied. The reactions using the polyethyleneglycol dialkyl ethers as solvents gave O- isopropylated 3-aminophenol in higher yields than using small amounts of dibenzo-18- crown-6 or the polyethyleneglycol dialkyl ethers as solvents.

Sur une transformation inattendue du β-methyl β-nitrostyrene en aldehyde salicylique

An unexpected route to o-hydroxybenzaldehyde is described. Thus, β-methyl β-nitrostyrene mixed with acetyl chloride and aluminium chloride at 0° yields upto 45% salicylaldehyde besides 2-acetoximino 1-chloro 1-phenyl propane and dichloromethyl benzene as minor products.

Olefin Hydrogenation by carbon monoxide and water using a platinum chloride-tin chloride catalyst system

The water gas shift catalyst system composed of K 2PtCl 4 and SnCl 45H 2O in HCl/HOAc/H 2O Torr of CO and 180 Torr of ethylene or propylene hydrogenates the olefin when heated at 88°C. The reaction with ethylene proceeds cleanly according to the equation C 2H 4 + CO + H 2O → C 2H 6 + CO 2 yielding 31 turnovers per Pt for a 24 h reaction time; the reaction with propylene is less clean, showing concurrent H 2 production from the shift reaction and isopropyl chloride formation from direct reaction of C 3H 6 with the HCL-containing medium. No evidence for significant hydroformylation is obtained. For the case of ethylene, no water gas shift catalysis is observed as long as olefin is present, and if H 2 is added to the reactant gases, it is not consumed in the course of ethane formation. Hydrogenation is thus thought to proceed via a metal hydride formed from CO oxidation, its reaction with olefin and protonation.