Dibutyl Ether Research Articles

Preparation of Novel Dideuterioallyl Mercaptan

Mass spectrometry is known to be the most accurate method for the quantitative analysis of flavor ingredients in food. For successful analysis with the method called ‘stable isotope dilution assay’, the isotopically labeled compound of each component is necessary. 1 A difference in mass units of two or more gives the best results in the quantitative determination of each ingredient. In order to analyze the allyl mercaptan present in the odor of bulgogi (a popular Korean dish) we needed to have allyl mercaptan-1,1-d2 or allyl mercaptan-2,3-d2. Neithr compound has been reported in the literature. One of the logical schemes for the synthesis is to preparing corresponding allyl alcohol (2) and converting it to the corresponding mercaptan. Allyl alcohol-d5 (CD2=CDCD2OH) is commercially available, but the -1,1- d2 or -2,3-d2 alcohol is not. Allyl alcohol-1,1-d2 has been reported to be prepared by reduction of acryloyl chloride with LiAlD 4. 2 There are numerous citations of the use of LiAlH 4 for the reduction of α ,β-unsaturated carboxylic acids to alkenols. For example, a reference book states that lithium aluminum hydride reduces exclusively the carbonyl group, even in an unsaturated acid with α ,β-conjugated double bonds. 3 The reference that was cited for the statement reported the reduction of acetylenedicarboxylic acid to 2-butene-1,4-diol (84% yield with 98% purity), fumaric acid to 2-butene-1,4diol (78% yield), acrylic acid ( 1) to allyl alcohol ( 2, 68% yield), and propiolic acid ( 5) to allyl alcohol ( 2, 85% yield). 4 Allyl alcohol (2) was not reduced to n-propyl alcohol (3) under the conditions, but such reduction was accomplished in 26% yield by heating the mixture in dibutyl ether at 100 o C for 3 h. 5 It should be pointed out that 0.75 mole of LiAlH 4 is required for reduction of 1 mole of RCOOH to RCH2OH and H2. But 0.283 mole of 1 and 0.35 mole of LiAlH4 in ether was reacted at room temperature for 16 h for the reduction of 1 to 2. 4

Production of Butyl Acetate by Catalytic Distillation: Process Design Studies

A simulation-based design method is employed to figure out the promising reactive distillation process configuration for the production of butyl acetate. The intrinsic kinetics developed for the esterification and the unwanted side reaction etherification over the Amberlyst-15 catalyst1 are utilized to evaluate the steady-state performance of different reactive distillation processes. A steady-state column model is developed and compared with experimental data from the literature.2,3 With this model, three different column configurations are investigated for the production of butyl acetate with the goal of eliminating the formation of byproduct dibutyl ether and achieving a high purity of the desired product butyl acetate. The following column configurations are explored: (a) a column with a nonreactive rectifying section and a reactive stripping section; (b) a column with a nonreactive rectifying section, a nonreactive stripping section, and a reactive middle section; and (c) a conventional distillation column with a cocurrent pump-around reactor. Configuration c is compared with the side reactor configuration, where the pump-around reactor is coupled to the column in a countercurrent fashion.

Catalytic Reactions of 1-Butanol over AlPO4Catalysts Induced by B2O3

A series of AlPO4–B2O3 samples containing 5–50 wt% B2O3 were prepared. Their textural properties were determined from studies of the adsorption of nitrogen at −196°C. The structural characteristics were investigated using DTA, TG, XRD and FT-IR methods. Surface acidity was determined from the adsorption of n-butylamine in non-aqueous media. The vapour-phase catalytic conversion of 1-butanol over the prepared catalysts was followed using a micro-catalytic pulse technique. The incorporation of B2O3 into AlPO4, as well as the calcination temperatures employed, led to significant changes in the textural parameters and crystallinity of the catalysts and in their surface acidity. The dehydration of 1-butanol to 1-butene and dibutyl ether (DBE) was strongly influenced by the surface acidity and the boron content of the samples.

Solubility of β-Carotene in Binary Solvents Formed by Some Hydrocarbons with Dibutyl Ether and 1,2-Dimethoxyethane

Experimental results are reported for the solubility of β-carotene in six binary mixed solvents formed by dibutyl ether with cyclohexane, hexane, and toluene and by 1,2-dimethoxyethane with cyclohexane, hexane, and toluene at 293.15 K. A spectral colorimeter was used for analysis of β-carotene concentration. The β-carotene solubility in the pure solvents increases in the order 1,2-dimethoxyethane < hexane < dibutyl ether < cyclohexane < toluene. The solubility data as a function of the binary solvent mass fractions were smoothed by the Myers Scott equation for asymmetric functions.

Measurements of densities, viscosities, speeds of sound and relative permittivities and excess molar volumes, excess isentropic compressibilities and deviations in relative permittivities and molar polarizations for dibutyl ether + benzene, + toluene and + p-xylene at different temperatures

The densities ρ, dynamic viscosities η, speeds of sound u, and relative permittivities ε r, for (dibutyl ether + benzene, or toluene, or p-xylene) have been measured at different temperatures over the whole composition range and at atmospheric pressure. The mixture viscosities have been correlated with semi empirical equations. Calculations of the speed of sound based on Nomoto’s equation have been found to be close to experimental values for the three mixtures and at two temperatures. Excess functions such as excess molar volumes V m E, excess isentropic compressibilities κ s E, deviations in relative permittivities δε r, and molar polarizations δP m were calculated and fitted to Redlich–Kister type equations.

Density, Surface Tension, and Refractive Index of Octane + 1-Alkanol Mixtures at T = 298.15 K

Surface tension and refractive index for binary mixtures of {octane + ethanol, + 1-propanol, + 1-butanol, + 1-pentanol, + 1-hexanol, + 1-heptanol, and + 1-octanol}, and density for {octane + ethanol} have been measured at T = 298.15 K for the whole composition range. From the experimental data we extract excess molar volumes, surface tension deviations, and changes of refractive index. All these experimental data are compared among them and with previous results of the binary mixtures hexane + 1-alkanol and dibutyl ether + 1-alkanol. Also we compare our present results with other published data when available.

Isothermal vapor–liquid equilibria for binary mixtures of carbon dioxide with diethylene glycol (diethyl, butyl, hexyl, or dibutyl) ether at elevated pressures

Isothermal vapor–liquid equilibrium (VLE) phase compositions were measured for four binary systems of carbon dioxide with diethylene glycol diethyl ether, diethylene glycol butyl ether, diethylene glycol hexyl ether, and diethylene glycol dibutyl ether at temperatures from 333.15 to 413.15 K and pressures up to 20 MPa. The saturated vapor composition of the ethers follows the order of diethylene glycol diethyl ether>diethylene glycol butyl ether>diethylene glycol dibutyl ether>diethylene glycol hexyl ether, while the solubility of carbon dioxide in the liquid obeys the sequence of diethylene glycol diethyl ether≈diethylene glycol dibutyl ether>diethylene glycol hexyl ether ≈ diethylene glycol butyl ether. Henry’s constants were calculated by fitting the Krichevsky–Ilinskaya (KI) equation to the isothermal equilibrium data. The constants increase with increasing temperature for each binary system. The new phase equilibrium data were correlated with several cubic equations of state with the van der Waals one-fluid mixing rules. Generally the Peng–Robinson (PR) equation of state with two binary interaction parameters yielded the best results.

Surface tensions, densities and refractive indexes of mixtures of dibutyl ether and 1-alkanol at T=298.15 K

The aim of our present work is to present measurements of the surface tension, density and refractive index for binary mixtures of dibutyl ether with eight 1-alcohols {C 4H 9OC 4H 9+C 3H 7OH,+C 4H 9OH,+C 5H 11OH,+C 6H 13OH,+C 7H 15OH,+C 8H 17OH,+C 9H 19OH and +C 10H 21OH} at the temperature of 298.15 K and atmospheric pressure. The experimental data are correlated by means of suitable empirical expressions, which relate the surface tension and refractive index of a mixture with its corresponding density. Also, calculated are the surface tension deviations and excess molar volumes from the measured data for all binary mixtures. The results of the study attending to the number of carbon atoms of the 1-alcohol are discussed.

Solubility of 2-methylbenzimidazole in ethers and ketones

Solid–liquid equilibria (SLE), have been measured from 270 K to the boiling temperature of the solvent for nine binary mixtures of 2-methylbenzimidazole (2MBI), with ethers (dipropyl ether, dibutyl ether, dipentyl ether, methyl 1,1-dimethylethyl ether (MTBE), methyl 1,1-dimethylpropyl ether (MTAE)) and with ketones (pentan-2-one, hexan-2-one, heptan-4-one, 4-methylpentan-2-one) using a dynamic method. The solubility of 2-methylbenzimidazole in ethers and ketones is lower than in alcohols and water and generally decreases with increasing molecular weight of the ether, or ketone. The highest intermolecular solute–solvent interaction is observed for the dipropyl ether and pentan-2-one. Experimental solubility results are compared with values calculated by means of the Wilson, UNIQUAC and NRTL equations utilizing parameters derived from SLE results. The existence of a solid–solid first-order phase transition in solute has been taken into consideration in the solubility calculation. The correlation of the (2-methylbenzimidazole+ketone) solubility data has been obtained with the average root-mean-square deviation of temperature σ T =1.0 K with every equation used.

Solubility of Imidazoles in Ethers

Solid−liquid equilibrium (SLE) has been measured from 270 K to the melting temperature of the solid for 15 binary mixtures of an imidazole (1H-imidazole, 2-methyl-1H-imidazole, and 1,2-dimethylimidazole) with ethers [dipropyl ether, dibutyl ether, dipentyl ether, methyl 1,1-dimethylethyl ether (tert-butyl methyl ether), and methyl 1,1-dimethylpropyl ether (tert-amyl methyl ether)] using a dynamic method. The solubility of imidazoles in ethers is lower than that in alcohols and in water and generally decreases with increasing of the ether chain length. Additionally, two liquid phases were observed for mixtures of 1H-imidazole and 1,2-dimethylimidazole in dibutyl ether and dipentyl ether. The intermolecular solute−solvent interaction is higher for branch chain ethers, and the mutual solubility is much higher, which results in one liquid phase being observed. Experimental results of solubility are compared with values calculated by means of the Wilson, UNIQUAC, and NRTL equations utilizing parameters derived from SLE results. The existence of a solid−solid first-order phase transition in 2-methyl-1H-imidazole has been observed and has been taken into consideration in the solubility calculation. The best correlation of the solubility data was obtained with the Wilson equation.

Group 5 and Group 6 Metal Halides as Very Efficient Catalysts for Acylative Cleavage of Ethers.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Liquid Densities, Kinematic Viscosities, and Heat Capacities of Some Alkylene Glycol Dialkyl Ethers

Liquid densities and heat capacities at 1 MPa, and kinematic viscosities at atmospheric pressure of monoethylene glycol diethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, triethylene glycol dibutyl ether, and dipropylene glycol dimethyl ether were measured in the temperature range (283.15 to 423.15) K. For each substance, experimental data were correlated with temperature using empirical polynomial equations. The experimental data of kinematic viscosity and heat capacity were used to evaluate the predictive capability of some estimation methods of the literature.

Highly Efficient Synthesis of Methylenecyclopropane

AbstractFor Abstract see ChemInform Abstract in Full Text.

Group 5 and group 6 metal halides as very efficient catalysts for acylative cleavage of ethers

Group 5 and 6 metal chlorides such as MoCl 5, WCl 6, NbCl 5 and TaCl 5 were found as very efficient catalysts for acylative cleavage of the C–O bond of ethers. Compared with conventional Lewis acid catalysts such as ZnCl 2, AlCl 3, SnCl 4 and TiCl 4, group 5 and 6 metal chlorides showed better results in the catalytic C–O bond cleavage of dibutyl ether with benzoyl chloride.

Preferential solvation in mixed solvents.

The Kirkwood–Buff integrals and the volume-corrected preferential solvation parameters for the first solvation shell of binary mixtures of tetrahydrofuran with many organic solvents, calculated from reported thermodynamic data at the temperatures for which these data were available, are reported. The co-solvents include c-hexane, methyl-c-hexane, n-heptane, i-octane, benzene, toluene, ethylbenzene, 1-chlorobutane, dichloromethane, 1,2-dichloroethane, chloroform, 1,1,1-trichloroethane, tetrachlorom-ethane, tetrachloroethene, hexafluoro benzene, ethanol, 1-propanol, 2-propanol, dibutyl ether, acetic acid, acetone, dimethyl sulfoxide, tetramethylene sulfone (sulfolane), acetonitrile, pyrrolidine, and triethylamine. The preferential solvation parameters of these mixtures are discussed in terms of the interactions that occur.

Excess molar volumes, and excess molar enthalpies of (N-methyl-2-pyrrolidinone + an ether ) at the temperature 298.15 K

Excess molar volumes VmE have been calculated from measured density values over the whole composition range at T= 298.15 K and atmospheric pressure for six { N -methyl-2-pyrrolidinone + 1,1-dimethylethyl methyl ether, or dipropyl ether, or 1,1-dimethylpropyl methyl ether, or diisopropyl ether, or dibutyl ether, or dipentyl ether}. Excess molar enthalpiesHmE were also measured for five { N -methyl-2-pyrrolidinone + 1,1-dimethylethyl methyl ether, or dipropyl ether, or 1,1-dimethylpropyl methyl ether, or diisopropyl ether, or dibutyl ether} at T= 298.15 K and atmospheric pressure. The results are discussed in terms of intermolecular associations. The experimental results have been correlated with the UNIQUAC and NRTL equations.

Liquid−Liquid Equilibria of the Ternary System Water + Phosphoric Acid + Tributyl Phosphate at 298.15 K and 323.15 K

Solubilities and liquid−liquid-phase equilibria for the ternary system water + phosphoric acid + tributyl phosphate are presented at (298.15 and 323.15) K. The binodal curves, tie lines, and distribution curves have been determined. The plait point compositions have been calculated by Hand's method. The extraction power of tributyl phosphate for phosphoric acid has been compared to those of methyl isobutyl ketone, dibutyl ether, isoamyl alcohol, and diethyl ketone. The extraction chemistry of H3PO4 by tributyl phosphate is also discussed.

Volume changes on mixing perfluoroalkanes with alkanes or ethers at 298.15 K

Excess molar volumes V E at 298.15 K have been determined by means of a vibrating-tube densimeter for binary mixtures of n-hexane with a perfluoroalkane, C 5–C 8, and of perfluorohexane with a n-alkane, C 5–C 8, or an ether (diethyl, dipropyl, dibutyl, butyl methyl, and butyl ethyl ether). The systems perfluoropentane+hexane, perfluorohexane+pentane or hexane or diethyl ether have been investigated in the entire mole fraction range, while the other mixtures only in the miscibility regions. The observed V E values are positive (up to 5.5 cm 3 mol −1) and among the largest known for non-electrolyte systems. Limiting partial molar volumes, V ̄ ° , have been evaluated for each component of the examined mixtures. The behaviour of V ̄ ° has been discussed in terms of the scaled particle theory (SPT) and of a simple group additivity scheme based on surface interactions. An estimate has been made of the average separation distance of solvent from solute molecules.

Radical addition of ethers to alkenes under dioxygen catalyzed by N-hydroxyphthalimide (NHPI)/Co(OAc) 2

The reaction of various ethers with alkenes bearing an electron-withdrawing substituent in the presence of N-hydroxyphthalimide combined with Co(OAc) 2 under dioxygen produced the corresponding adducts in which oxygen is incorporated to alkenes in good yields. Oxcetane, furan and pyrane smoothly added to ethyl fumarate even at room temperature to give coupling products in high yields. An acyclic ether like dibutyl ether also added to fumarate under mild conditions to give a hydroxylated adduct in satisfactory selectivity.

Displacement of H3CB(C6F5)3- Anions from Zirconocene Methyl Cations by Neutral Ligand Molecules: Equilibria, Kinetics, and Mechanisms

The displacement of the MeB(C6F5)3- anion from seven different zirconocene methyl cations by neutral Lewis bases, such as dimethylaniline, benzyldimethylamine, and dinbutyl ether, was investigated by 1D and 2D NMR spectroscopy. Equilibrium constants for reactions with dinbutyl ether change by factors of less than 5 between the zirconocene contact ion pairs studied, despite substantial steric differences. Rate constants of this displacement reaction, however, change by a factor of more than 105 between Me2Si(C5H4)2ZrMe+MeB(C6F5)3-, the most “open” complex, and rac-Me2Si(2-Me-BzInd)2ZrMe+MeB(C6F5)3-, the most highly substituted species studied. Kinetic and stereochemical data indicate that Lewis base−anion exchange proceeds by way of an associative mechanism, which occurs without side change of the zirconium-bound methyl group. DFT calculations support an associative substitution mechanism and propose five-coordinated reaction intermediates with the Lewis base coordinated to the central coordination site.