Butyl Ethyl Ether Research Articles

RIFM fragrance ingredient safety assessment, sec-butyl ethyl ether, CAS Registry Number 2679-87-0

• sec -Butyl ethyl ether; a safety assessment based on RIFM's criteria. • A safety assessment based on 7 human health endpoints plus environmental. • All endpoints were cleared using target data, read-across, and/or TTC.

Saccharomonopyrones A-C, New α-Pyrones from a Marine Sediment-Derived Bacterium Saccharomonospora sp. CNQ-490.

Intensive study of the organic extract of the marine-derived bacterium Saccharomonospora sp. CNQ-490 has yielded three new α-pyrones, saccharomonopyrones A–C (1–3). The chemical structures of these compounds were assigned from the interpretation of 1D, 2D NMR and mass spectrometry data. Saccharomonopyrone A (1) is the first α-pyrone microbial natural product bearing the ethyl-butyl ether chain in the molecule, while saccharomonopyrones B and C possess unusual 3-methyl and a 6-alkyl side-chain within a 3,4,5,6-tetrasubstituted α-pyrone moiety. Saccharomonopyrone A exhibited weak antioxidant activity using a cation radical scavenging activity assay with an IC50 value of 140 μM.

Closed-system pyrolysis of butyl ethyl ether and sec-butyl ethyl ether at 20 MPa—Mechanistic insights

Natural macromolecular organic matter (kerogen) possesses a complex structure with a variety of subunits with a multitude of functional groups (e.g. numerous ether bonds). During thermal maturation, a preferential cleavage of labile bonds leads to fragmentation and the gradual liberation of CO2, H2O and organic compounds (e.g., hydrocarbons). Though, a detailed understanding of the kinetics and mechanisms of individual thermochemical reactions during maturation is difficult due to the complex structure, but would enable an improved prediction of the composition of released organic products or gas pressures. Pyrolysis studies of organic model compounds are one approach for a better understanding of individual bond cleavage pathways in kerogen and for the derivation of kinetic parameter.Here we present the results of closed-system pyrolysis experiments of the model compounds butyl ethyl ether (BEE) and sec-butyl ethyl ether (SBEE) at elevated pressure (20MPa) and temperatures (150–345°C).C1–C4 alkanes and carbonyl compounds (CO or butanone) account for the pyrolysis’ main products together with alkenes as byproducts. A detailed radical chain reaction mechanism is proposed to explain the formation pathways of the main products. The activation energy for H abstraction from CH bonds in the ether model compounds controls the formation of favored ether radicals whose decomposition gives rise to the main products. CO2 and several esters are byproducts whose formation can be attributed to the reaction of alkoxy radicals with CO or aldehydes – or to some extent ether decomposition processes induced by oxygen impurities.

Vapor–Liquid Equilibria Measurements for Di-n-Propyl Ether and Butyl Ethyl Ether with n-Heptane

Isobaric vapor–liquid equilibrium (VLE) data were measured for two binary systems comprising n-heptane with one of di-n-propyl ether (DNPE) or butyl ethyl ether (BEE) at 60 kPa. Slight positive deviations from ideality were apparent in both systems, but not so strong as to result in azeotropic behavior. The data for both systems were shown to be thermodynamically consistent using both the Wisniak L/W and McDermott-Ellis consistency tests. Data were further well correlated by the nonrandom two-liquid (NRTL) activity coefficient model and fairly predicted using the Dortmund-modified UNIFAC model. The data presented serve to fill the gap in the literature for data sets of structural isomers of C6 ethers with n-heptane, where data for the linear isomers are absent. This data, combined with that available for the branched isomers, serve to highlight the role of polar functional group location on associated mixture behavior in such systems.

Calorimetric and acoustic study of binary mixtures containing an isomeric chlorobutane and butyl ethyl ether or methyl tert-butyl ether

Densities and speeds of sound in the temperature range 283.15–313.15 K have been measured for the binary mixtures formed by an isomeric chlorobutane (1-chlorobutane, 2-chlorobutane, 1-chloro-2-methylpropane, or 2-chloro-2-methylpropane) and butyl ethyl ether or methyl tert-butyl ether. Excess isentropic compressibilities were calculated from the experimental data. Excess enthalpies at T = 298.15 K are also included for the same binary mixtures. All these properties provide an insight into the nature of interactions operating on the present systems. Finally, the Prigogine–Flory–Patterson theory has been used to analyze the H E results and to estimate the isentropic compressibility values of the mixtures at T = 298.15 K.

Refractive Properties of Binary Mixtures Formed by an Isomer of Chlorobutane and Butyl Ethyl Ether

Refractive indices of the binary mixtures containing an isomer of chlorobutane (1-chlorobutane, 2-chlorobutane, 2-methyl-1-chloropropane, or 2-methyl-2-chloropropane) and butyl ethyl ether have been measured at seven temperatures from T = 283.15 to 313.15 K From these data refractive index deviations were calculated and correlated with a Redlich-Kister polynomial expansion. The refractive index deviations were found positive. Finally, from these refractive indices both densities and surface tensions of the studied systems were predicted and compared with previously reported values.

Ion exchange resins as catalysts for the liquid-phase dehydration of 1-butanol to di-n-butyl ether

This work reports the production of di-n-butyl ether (DNBE) by means of 1-butanol dehydration in the liquid phase on acidic ion-exchange resins. Dehydration experiments were performed at 150°C and 40bar on 13 styrene-codivinylbenzene ion exchangers of different morphology. By comparing 1-butanol conversions to DNBE and initial reaction rates it is concluded that oversulfonated resins are the most active catalysts for 1-butanol dehydration reaction whereas gel-type resins that swell significantly in the reaction medium as well as the macroreticular thermostable resin Amberlyst 70 are the most selective to DNBE. The highest DNBE yield was achieved on Amberlyst 36. The influence of typical 1-butanol impurities on the dehydration reaction were also investigated showing that the presence of 2-methyl-1-propanol (isobutanol) enhances the formation of branched ethers such as 1-(1-methylpropoxy) butane and 1-(2-methylpropoxy) butane, whereas the presence of ethanol and acetone yields ethyl butyl ether and, to a much lesser extent, diethyl ether.

Surface study of binary mixtures containing chlorinated and oxygenated compounds

We report in this work, experimental surface tensions for binary mixtures of isomeric chlorobutanes with butyl ethyl ether or diisopropyl ether from T=283.15K to 303.15K measured with a drop volume tensiometer. The surface tension data have been correlated with a Redlich–Kister type equation. More information about the surface behaviour can be obtained combining these results with previously reported VLE measurements to calculate the excess surface composition of ether in the mixture. Finally, the results have been compared to the predictions obtained using a group contribution method.

Experimental and Predicted Viscosities of Binary Mixtures Containing Chlorinated and Oxygenated Compounds

This study presents the viscosities, both kinematic and dynamic, of binary mixtures of 1-chlorobutane, 2-chlorobutane, or 1-chloro-2-methylpropane with butyl ethyl ether or methyl tert-butyl ether from \(T = 283.15\) K to \(T = 313.15\) K at atmospheric pressure as a function of composition. Kinematics viscosities were measured using an Ubbelohde viscometer. The dynamic viscosities were obtained from experimental kinematic viscosities and previously reported density data. The viscosity results have been employed to check the reliability of the Wu-UNIFAC method.

Experimental and predicted properties of the binary mixtures containing an isomeric chlorobutane and butyl ethyl ether

Densities of the binary systems containing an isomer of chlorobutane (1-chlorobutane, 2-chlorobutane, 2-methyl-1-chloropropane, or 2-methyl-2-chloropropane) and butyl ethyl ether have been measured over the temperature range (283.15 to 313.15)K. Moreover, isothermal (vapour+liquid) equilibria have also been determined at three temperatures (T=(288.15, 298.15, and 308.15)K). Excess properties have been obtained from the experimental data and correlated. Finally, the VTPR model has been used to predict densities and (vapour+liquid) equilibria of the binary systems studied.

The pure rotational spectra of the two lowest energy conformers of the asymmetric ether C 4H 9OC 2H 5

An experimental study has been performed shedding light on the conformational energies of the asymmetric ether n-butyl ethyl ether. Rotational spectroscopy between 7.8 GHz and 16.2 GHz has identified two conformers of n-butyl ethyl ether, C 4H 9OC 2H 5. In these experiments spectra were observed as the target compound participated in an argon expansion from high to low pressure causing molecular rotational temperatures to be below 4 K. For one conformer, 95 pure rotational transitions have been recorded, for the second conformer, 20 pure rotational transitions were recorded. Rotational constants and centrifugal distortion constants are presented for both butyl ethyl ether conformers. The structures of both conformers have been identified by exploring the multi-dimensional molecular potential energy surface using ab initio calculations. From the numerous low energy conformers identified using ab initio methods, the three lowest conformers were pursued at increasingly higher levels of theory, i.e. complete basis set extrapolations, coupled cluster methods, and also taking into consideration zero point vibrational energies. The two conformers observed experimentally are only revealed to be the two lowest energy conformers when high levels of quantum chemical methodologies are employed.

Thermodynamic study of perfluorohexane + ether mixtures : VLE, LLE, and HE

Vapour–liquid equilibria (VLE), liquid–liquid equilibria (LLE), and excess enthalpies ( H E) of binary mixtures of perfluoro- n-hexane plus an ether (diethyl, dipropyl, dibutyl, butyl methyl, and butyl ethyl ether), have been determined using a head-space gas-chromatographic technique, a turbidimetric apparatus, and a heat-flow calorimeter, respectively. A recently designed titration technique and calculation procedure have been used to obtain H E from heats of solution. The observed liquid–liquid coexistence curves have been compared with those predicted by the activity coefficients γ i and their temperature dependence. All mixtures are strongly endothermic ( H E > 0) and show large positive deviations from ideality ( G E > 0), which increase with the size of the ether. Molecular interactions have been examined by calculating and discussing solvation functions and Kirkwood–Buff (KB) integrals. Perfluorohexane proved to be an inert molecule that interacts with ethers more weakly than hexane.

Practical Syntheses of Neopentyl Alcohol and sec-Butyl Ethyl Ether Using Marukasol as a Solvent

By using Marukasol, neopentyl alcohol and sec-butyl ethyl ether have been obtained in good yields with easy operations. Thus, neopentyl alcohol was obtained from tert-butylmagnesium chloride and paraformaldehyde in 76% isolated yield with >99% purity using Marukasol as an effective extraction solvent. On the other hand, sec-butyl ethyl ether was obtained from sodium sec-butoxide with ethyl iodide in Marukasol in 67% yield with >99% purity.

Vapor−Liquid Equilibrium Data for the Binary Decafluoropentane (HFC-43-10meec) + Heptane, Decafluoropentane + Butyl Ethyl Ether, Octafluorobutane (HFC-338pcc) + Butyl Ethyl Ether, and Heptafluoro Propyl Methyl Ether (HFE-347mcc) + HFC-338pcc Systems at 101.3 kPa

Isobaric vapor−liquid equilibria were measured for the four binary systems of decafluoropentane (HFC-43-10meec) + heptane, decafluoropentane + butyl ethyl ether, octafluorobutane (HFC-338pcc) + butyl ethyl ether, and heptafluoro propyl methyl ether (HFE-347mcc) + HFC-338pcc systems at atmospheric pressure. The HFC-43-10meec + heptane system formed a minimum-boiling azeotrope. The experimental data were correlated by the Wilson and NRTL models. The Wilson and NRTL equations gave similar results.

Determination of fuel dialkyl ethers and BTEX in water using headspace solid-phase microextraction and gas chromatography–flame ionization detection

A simple procedure for the determination of methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), ethyl butyl ether (EBE), tert-amyl methyl ether (TAME), benzene, toluene, ethylbenzene, and xylenes (BTEX) in water using headspace (HS) solid-phase microextraction (HS-SPME) was developed. The analysis was carried out by gas chromatography (GC) equipped with flame ionization detector (FID) and 100% dimethylpolysiloxane fused capillary column. A 2 7–4 Plackett–Burman design for screening and a central composite design (CCD) for optimizing the significant variables were applied. Fiber type, extraction temperature, sodium chloride concentration, and headspace volume were the significant variables. A 65 μm poly(dimethylsiloxane)-divinylbenzene (PDMS-DVB) SPME fiber, 10 °C, 300 g/l, and 20 ml of headspace (in 40 ml vial) were respectively chosen for the best extraction response. An extraction time of 10 min was enough to extract the ethers and BTEX. The relative standard deviation (R.S.D.) for the procedure varied from 2.6 (benzene) to 8.5% (ethylbenzene). The method detection limits (MDLs) found were from 0.02 (toluene, ethylbenzene, and xylenes) to 1.1 μg/l (MTBE). The optimized method was applied to the analysis of the rivers, marinas and fishing harbors surface waters from Gipuzkoa (North Spain). Three sampling were done in 1 year from June 2002 to June 2003. Toluene was the most detected analyte (in 90% of the samples analyzed), with an average concentration of 0.56 μg/l. MTBE was the only dialkyl ether detected (in 15% of the samples) showing two high levels over 400 μg/l that were related to accidental fuel spill.

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.

Vapor−Liquid Equilibrium Data for the Four Binary Systems Containing Fluorocarbon, Hydrofluorocarbon, and Fluorinated Ethers at 101.3 kPa

Isobaric vapor−liquid equilibria were measured for the four binary systems of perfluoro-2-methylpentane (FC-5114mmyc2) + perfluorooctane (FC-7118mc6), 1,1,1,2,2,3,3,4,4-nonafluorohexane (HFC-569mccf) + octane, 2,2,2-trifluorodiethyl ether (HFE-356mf-f) + butyl ethyl ether, and methylperfluoroisopropyl ether (HFE-347 mmy) + heptane at atmospheric pressure. The HFE-356mf-f + butyl ethyl ether system formed a minimum boiling azeotrope. The experimental data except for those for the FC-5114mmyc2 + FC-7118mc6 system were correlated by the Wilson and NRTL activity coefficient models. The Wilson and NRTL equations gave similar results. The VLE for the FC-5114mmyc2 + FC-7118mc6 system was predicted to be an ideal solution.

Analysis of water samples for trace levels of oxygenate and aromatic compounds using headspace solid-phase microextraction and comprehensive two-dimensional gas chromatography

Headspace solid-phase microextraction (SPME) and comprehensive two-dimensional gas chromatography (C2DGC) have been applied to the quantitative analysis of trace levels of oxygenate and aromatic compounds. The oxygenates studied were methyl-tert-butyl ether (MTBE) and ethyl butyl ether (EBE). The aromatics studied were the BTEX compounds, benzene, toluene, ethylbenzene, and xylenes. Both the oxygenates and aromatics are components of gasoline commonly found in groundwater near leaking underground storage tanks. The method involves extraction and preconcentration using a fused-silica fiber coated with a combination of polydimethylsiloxane and porous carbon followed by a volatility-by-polarity comprehensive two-dimensional gas chromatographic analysis with flame ionization detection. Experimental results yielded method detection limits of 360–630 parts per trillion (v/v), with calibration plots exhibiting a linear range over approximately three orders of magnitude. Reproducibility, as indicated by typical relative standard deviation (RSD) values for replicate runs, was 10%. C2DGC resolved all oxygenate and BTEX components from all traditional one-dimensional GC coeluters present in standard gasoline samples. The method is fast, is experimentally simple, and uses no solvent. © 1998 John Wiley & Sons, Inc. J Micro Sep 10: 597–604, 1998

Analysis of water samples for trace levels of oxygenate and aromatic compounds using headspace solid‐phase microextraction and comprehensive two‐dimensional gas chromatography

Headspace solid-phase microextraction (SPME) and comprehensive two-dimensional gas chromatography (C2DGC) have been applied to the quantitative analysis of trace levels of oxygenate and aromatic compounds. The oxygenates studied were methyl-tert-butyl ether (MTBE) and ethyl butyl ether (EBE). The aromatics studied were the BTEX compounds, benzene, toluene, ethylbenzene, and xylenes. Both the oxygenates and aromatics are components of gasoline commonly found in groundwater near leaking underground storage tanks. The method involves extraction and preconcentration using a fused-silica fiber coated with a combination of polydimethylsiloxane and porous carbon followed by a volatility-by-polarity comprehensive two-dimensional gas chromatographic analysis with flame ionization detection. Experimental results yielded method detection limits of 360–630 parts per trillion (v/v), with calibration plots exhibiting a linear range over approximately three orders of magnitude. Reproducibility, as indicated by typical relative standard deviation (RSD) values for replicate runs, was 10%. C2DGC resolved all oxygenate and BTEX components from all traditional one-dimensional GC coeluters present in standard gasoline samples. The method is fast, is experimentally simple, and uses no solvent. © 1998 John Wiley & Sons, Inc. J Micro Sep 10: 597–604, 1998

Rate constants for reactions of OH radicals with a series of asymmetrical ethers andtert-Butyl alcohol

Absolute rate constants for the reactions of OH radicals with butyl ethyl ether (k1), methyl tert-butyl ether (k2), ethyl tert-butyl ether (k3) tert-amyl methyl ether (k4) and tert-butyl alcohol (k5) have been measured over the temperature range 230–372 K using a pulsed laser photolysis-laser induced fluorescence (PLP-LIF) technique. The temperature dependence of k1 − k5 when expressed in Arrhenius form gave: k1 = (6.59 ± 0.66) × 10 −12 exp|(362 ± 60)/T|, k2 = (5.03 ± 0.27) × 10−12 exp|&minus(133 ± 30)/T|, k3 = (4.40 ± 0.24) × 10−12 exp|(210 ± 37)/T|,k4 = (4.7 ± 0.7) × 10−12 exp|(82 ± 85)/T|, and k5 = (2.66 ± 0.48) × 10−12 exp| −(270 ± 130)/T|. However, the Arrhenius plots for k1–k5, were slightly curved and are best fitted by the three parameter fits which are given in the article. The room temperature values of k1, k2, k3, k4, and k5 are (2.08 ± 0.23) × 10−11, (3.13 ± 0.36) × 10−12, (8.80 ± 0.50) × 10−12, (6.28 ± 0.45) × 10−12, and (1.08 ± 0.10) × 10−12, respectively, in cm3 molecule−1 s−1. © 1996 John Wiley & Sons, Inc.