Ethyl Hexyl Acetate Research Articles

Amberlyst-15 catalysed retro-Claisen condensation of β-diketones with alcohols: A practical approach to synthesize esters and ketoesters

Esters are fundamental class of organic compounds with tremendous industrial applications. They are generally synthesized via the condensation of alcohol with acid. Herein, we report synthesis of esters and keto esters via retro-Claisen condensation of alcohols with β-diketones in presence of Amberlyst-15, a commercially available heterogeneous catalyst. The methodology is applied to synthesize several industrially relevant acetates, such as n-butyl acetate, isobutyl acetate, 2-ethylhexyl acetate and isopropyl acetate in multi-gram scale. When 2-acetyl cyclohexanone or 2-acetyl cyclopentanone were used as β-diketones, long chain keto-esters formed as sole products in excellent yields. The reaction tolerates a wide range of functional groups, such as olefins, alkynes, halides, nitro and esters. Furthermore, the protocol allows late-stage acetylation of naturally occurring alcohols. The methodology provides a practical approach for large scale synthesis of esters using fixed-bed continuous process. The catalyst can be recovered from the reaction mixture and reused up to 5 cycles without significant change in catalytic activity. To the best of our knowledge, this is the first example of a reusable Brønsted acid catalyst used in the synthesis of esters via retro-Claisen type condensation of alcohols and β-diketones.

Electrophysiological and behavioral responses of the moth, Trabala vishnou gigantina Yang, 1978 (Lepidoptera: Lasiocampidae) to volatiles produced by the plant, Hippophae rhamnoides L. (Elaeagnaceae)

Plant volatiles are important to herbivorous insects for foraging and determining host location. Considering the damage caused by the moth species, Trabala vishnou gigantina Yang, 1978 (Lepidoptera: Lasiocampidae), to sea buckthorn, Hippophae rhamnoides L. (Elaeagnaceae), plantations, this study examined the antennal and behavioral responses of T. vishnou gigantina to the volatiles produced by H. rhamnoides. Electroantennographs revealed large differences between males and females concerning active odor profiles. Subtractive bioassays conducted in a flight tunnel showed that the 14-component mixture (BLE) and a subtracted five-component mixture of 2-ethylhexyl acetate, longifolene, 3-heptanone, α-ocimene, and 6-methyl-5-hepten-2-one (treatment T-13) elicited equivalent responses in females. The BLE and a four-component mixture of 1-butanol, 3-methyl-1-butanol, 2-ethylhexyl acetate, and longifolene (treatment T-n) elicited equivalent responses in males. These findings indicate the potential for developing specific synthetic host plant lures and traps for T. vishnou gigantina. The attractive volatiles will also be helpful in future studies to gain further insights into the olfactory information processing in these insects.

LCA of sustainable biodiesel production from fried Borassus flabellifer oil in energy-proficient reactors: Impact assessment of multi fuel-additives on pour point, NOx and engine performance

Sustainable reductions in energy and time requirements in fried palm oil (Borassus flabellifer) biodiesel (FPOB) production (97% yield) have been achieved in differently powered reactors viz., low-energy infrared radiation (LEIR) (0.131 kWh) and LEIR with ultrasonic-energy (LEIRUE) (0.12 kWh) in comparison with conventional heating energy (CHE: 0.664 kWh). Life cycle assessment (LCA) employing IMPACT 2002 + indicated adverse environmental impacts of energy-intensive CHE reactor generating 28.4% more respiratory organics, 67.6% augmented global warming and additional 38.3% energy utilization in comparison with the novel LEIRUE reactor. Feasibility of 2-ethylhexyl acetate (2EHA), triacetin (TA), and 5 other esters were assessed as fuel additives (FAs) for FPOB (B100) and diesel-FPOB (B10) in conventional diesel engine. The optimal 1:1 v/v mix of the two best FAs (2EHA + TA) i.e., ETA was blended in 5, 7, and 10 vol% with B10 and B100 for impact assessment. Remarkably, the best 7 vol% ETA blending could successfully diminish pour point and NOx emission by 36 ± 1% and 28 ± 1% respectively for B100. The LCA also confirmed that 7 vol% ETA (for B10 and B100) blending could manage all the impact categories ascertaining environmental sustainability. Thus, ETA can find applications as a potent FA for B100 and B10 blends.

Antagonistic fungal endophytes and their metabolite-mediated interactions against phytopathogens in rice

Endophytes regulate physiological activities of host plants by conferring resistance against abiotic stress, insect, nematode, and diseases. Besides, they produce novel natural bioactive compounds with potential applications in agriculture, medicine, and food industry. In the present study, seven antagonistic fungal endophytes showing anti-fungal and anti-bacterial activities were isolated from rice leaves and identified as Paecilomyces tenuis EF1, Talaromyces pinophilus EF2, Nigrospora sphaerica EF3, Nigrospora oryzae EF4, Trichoderma longibrachiatum EF5, and EF7 and Aspergillus terreus EF6. Of these, T. longibrachiatum EF5 had the highest growth inhibition activity against the tested fungal (23%–82%) and bacterial plant pathogens (13%–46%). Soluble metabolites such as aliphatic organic acids, (e.g., lactic, acetic, hydroxyl-methyl valeric acids, ethyl hexyl acetate, salbutamol sulfate, dodecanone, octadecanoic, octaheptanoic and butanenoic acids), aromatic nitroamino compounds (Benzyl glycinate), and volatile metabolites, (e.g., 2,3- butanediol dinitrate, pentadecane, tetramethyl hexahydro napthalenone, 1-iodo-2-methylundecane) were detected through FT-IR and GC-MS–TD, respectively. The metabolite induced antagonistic activity of EF5 was much pronounced against phytopathogens such as Magnaporthe grisea, Rhizoctonia solani, and Macrophomina phaseolina. Also, the volatile organic compounds (VOCs) of T. longibrachiatum EF5 enhanced the lateral root formation by modulating auxin biosynthesis.

Aroma volatile changes in non-climacteric melons with introgression in linkage group X at three stages of maturity

A near-isogenic line of melon (NIL) SC10-2 with differential textural traits was compared with a control 'Piel de Sapo' (PS) at three stages of commercial maturity (G1, G2, G3). Flesh samples were taken and the aroma volatiles were extracted by solid phase microextraction and further analyzed by gas chromatography coupled to mass spectrometry. Data were fully integrated and analyzed by univariate and multivariate statistical techniques. A significant pedigree effect was found for 6-methylheptan-2-one and 2-ethylhexyl-2-hydroxybenzoate, with higher levels in SC10-2 than in PS, while 2-methylpent-1-ene was absent from PS. By contrast, heptanal levels were higher in PS (at stages G1 and G3), while 2-ethylhexyl acetate, 2-methylpropan-1-ol, methyl propionate and one unidentified compound (retention time 24.07 min) were absent from the NIL. A marked interaction between pedigree and maturity was found for 1-heptanol (higher levels in PS than in SC10-2, but only in G2), while the opposite effect was observed for 6(E)-6-[(Z)-but-2-enylidene]-1,5,5-trimethylcyclohexene (in G1) and 3,5-dimethylcyclohexanone (in G1 and G2). Only a few aroma volatiles were associated with textural traits at harvest (flesh firmness, juiciness, stylar-end hardness). Eleven aroma volatile QTLs were mapped in linkage group X, but only one was seen to be maturity dependent. Introgression of SC10-2 had a greater influence on aroma volatiles than the stage of fruit maturity at harvest.

Surface tension of four oxygenated fuels: experiment and correlation

In this work, a pendant drop apparatus was developed and tested by the surface tension measurement of toluene. Then, the surface tensions of 2-Methoxyethanol, 2-Methoxyethyl ether, 2-Ethylhexyl acetate and Diethyl succinate were measured in the temperature range from (303.15–393.15) K. The surface tension correlations were developed as a function of temperature with the experimental data, and the average absolute deviations were 0.041 mN m−1, 0.064 mN m−1, 0.041 mN m−1 and 0.052 mN m−1 for 2-Methoxyethanol, 2-Methoxyethyl ether, 2-Ethylhexyl acetate and Diethyl succinate, respectively.

Decreased quality and off-flavour compound accumulation of 3–10 kDa fraction of pine nut (Pinus koraiensis) peptide during storage

Pine nut peptide possesses good antioxidant activity. But the research related to the decreased quality and the development of off-flavour during storage is limited. In the present study, a 3–10 kDa fraction of pine nut (Pinus koraiensis) peptide (PNP 3–10 kDa) was prepared by enzymolysis and ultrafiltration. Thereafter, PNP 3–10 kDa was stored for 30 days at 75% relative humidity and 25 °C. Changes in DPPH radical scavenging capacity, secondary structure (by FT-MIR), surface structure (by SEM) and volatile compounds (by SPME-GC-MS) were measured at various time intervals over thirty days. Results showed that the DPPH radical scavenging capacity decreased from 76.91% ± 0.49% to 40.50% ± 0.84% with the accumulation of volatile compounds. The secondary structure and surface structure was not changed. However, the form and size of PNP 3–10 kDa particle were changed dramatically during the storage. In total 15 volatile compounds were identified during the storage. The intensity of volatile compounds presented dynamic changes. 2-Ethylhexyl acetate and pyrazines were mainly formed through esterification and Maillard reaction. The reactions appeared to be strongest by the sixth day. Principal component analysis (PCA) indicated that 30 days' storage could cause remarkable changes to the volatile compounds.

Changes in the emission of volatile compounds from Hippophae rhamnoides ssp. sinensis induced by Holcocerus hippophaecolus (Lepidoptera:Cossidae)

The study explores changes in variety and content of volatile compounds in Hippophae rhamnoides ssp. sinensis damaged by Holcocerus hippophaecolus. Volatiles of healthy and artificially infested plants leaves were collected during 0–51 hours using continuous dynamic headspace-collection and analysed by using Automated Thermal Desorption-Gas Chromatography-Mass Spectrometry. Thirty-one compounds were identified, including seven alcohols, four esters, two terpenes, six aldehydes, five alkanes, two olefins, three ketones and two benzodiazepines. Compounds of (Z)-3-Hexenyl-3-methylbutanoateand 2-ethylhexyl acetate were herbivore-induced compounds. Olefins, ketones, benzodiazepines, terpenes and alkanes increased shortly after insect feeding. Aldehydes, alcohols and esters decreased in generally. Release regularity and function of compounds respectively discussed followed, especially including 2-ethylhexanol, alpha-terpineol, phytol, methyl salicylate, (Z)-3-Hexenyl-3-methylbutanoate, 2-ethylhexyl acetate, longifolene, 1,3,6-octatriene, 3,7-dimethyl-, hexanal, (Z)-3-hexen-1-ol acetate, with the purpose to approve basic date for disaster mechanisms of H. hippophaecolus.

Aluminum and brain transaminase activity

This paper presents three poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) composite-based sensors for detecting volatile organic compunds (VOCs) in the presence of water vapor applicable in breath based sensing. Three sensors with varying sensitivities to acetone, water, ethanol, isoprene, and 2-ethylhexyl acetate (2-EHA), representing VOCs found in breath, have been developed. A sensor fabricated by spray coating PVDF-HFP/C65 composite (Sensor-1) exhibited a 52.6% increase in resistance when exposed to acetone, while the change was less than 0.34% for water. The resistance changes for ethanol, isoprene, and 2-EHA, were 5.6%, 3%, and 0.11%, respectively. The second sensor (Sensor-2), with a two-layer design of PVDF-HFP and PVDF-HFP/C65, was fabricated by a spin coating method, which exhibited improved response times. The response times of Sensor-2 compared to Sensor-1 decreased by 52% for acetone, 92% for water, 30% for ethanol, and 61% for isoprene. In the third sensor (Sensor-3), the addition of carbon nanotube (CNT) in the composite (PVDF-HFP/C65/CNT) caused a decrease in resistance when exposed to water. This is in contrast to Sensors 1 & 2 where resistance increased for all VOCs, and provides a higher selectivity for the system. The results from the three sensors were analyzed using principal component analysis (PCA) and it was demonstrated that the combined responses of these sensors provide a high selectivity. The sensor fabrication, testing methods, and results are presented and discussed.

Liquid Density of 2-Methoxyethyl Acetate, 2-Ethylhexyl Acetate, and Diethyl Succinate at Temperatures from 283.15 K to 363.15 K and Pressures up to 100 MPa

The density data for 2-ethylhexyl acetate, 2-methoxyethyl acetate, and diethyl succinate were reported. The density measurements were conducted with a high-pressure vibrating-tube densimeter over 9 isotherms at (283.15 to 363.15) K and 16 isobars at (0.1 to 100) MPa. The uncertainty of each obtained datum was estimated, and the expanded uncertainties of density measurements with a confidence level of 0.95 (k = 2) of density measurement for 2-ethylhexyl acetate, 2-methoxyethyl acetate, and diethyl succinate are 0.1 %. The experimental densities were correlated with the Tait-type equation, and the absolute average percentage deviations were 0.010 %, 0.009 %, and 0.011 % for 2-ethylhexyl acetate, 2-methoxyethyl acetate, and diethyl succinate, respectively. In addition, the isothermal compressibility and the isobaric thermal expansivity were derived from the Tait-type equation.

Poly(vinylidene fluoride-hexafluoropropylene) composite sensors for volatile organic compounds detection in breath

This paper presents three poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) composite-based sensors for detecting volatile organic compunds (VOCs) in the presence of water vapor applicable in breath based sensing. Three sensors with varying sensitivities to acetone, water, ethanol, isoprene, and 2-ethylhexyl acetate (2-EHA), representing VOCs found in breath, have been developed. A sensor fabricated by spray coating PVDF-HFP/C65 composite (Sensor-1) exhibited a 52.6% increase in resistance when exposed to acetone, while the change was less than 0.34% for water. The resistance changes for ethanol, isoprene, and 2-EHA, were 5.6%, 3%, and 0.11%, respectively. The second sensor (Sensor-2), with a two-layer design of PVDF-HFP and PVDF-HFP/C65, was fabricated by a spin coating method, which exhibited improved response times. The response times of Sensor-2 compared to Sensor-1 decreased by 52% for acetone, 92% for water, 30% for ethanol, and 61% for isoprene. In the third sensor (Sensor-3), the addition of carbon nanotube (CNT) in the composite (PVDF-HFP/C65/CNT) caused a decrease in resistance when exposed to water. This is in contrast to Sensors 1 & 2 where resistance increased for all VOCs, and provides a higher selectivity for the system. The results from the three sensors were analyzed using principal component analysis (PCA) and it was demonstrated that the combined responses of these sensors provide a high selectivity. The sensor fabrication, testing methods, and results are presented and discussed.

Effect of the Side Chains and Anode Material on Thermal Stability and Performance of Bulk-Heterojunction Solar Cells Using DPP(TBFu)2Derivatives as Donor Materials

An optimized fabrication of bulk-heterojunction solar cells (BHJ SCs) based on previously reported diketopyrrolopyrrole donor, ethyl-hexylated DPP(TBFu)2, as well as two new DPP(TBFu)2derivatives with ethyl-hexyl acetate and diethyl acetal solubilizing side-chains and PC60BM as an acceptor is demonstrated. Slow gradual annealing of the solar cell causing the effective donor-acceptor reorganization, and as a result higher power conversion efficiency (PCE), is described. By replacing a hole transporting layer PEDOT:PSS with MoO3we obtained higher PCE values as well as higher thermal stability of the anode contact interface. DPP(TBFu)2derivative containing ethyl-hexyl acetate solubilizing side-chains possessed the best as-cast self-assembly and high crystallinity. However, the presence of ethyl-hexyl acetate and diethyl acetal electrophilic side-chains stabilizes HOMO energy of isolated DPP(TBFu)2donors with respect to the ethyl-hexylated one, according to cyclic voltammetry.

Synthesis of 2-Ethylhexyl Acetate by Transesterification of Methyl Acetate with 2-Ethylhexanol

Synthesis of 2-Ethylhexyl Acetate by Transesterification of Methyl Acetate with 2-Ethylhexanol

Simulated Moving Bed Reactor for the Synthesis of 2-Ethylhexyl Acetate. Part I: Experiments and Simulations

Reactive chromatography (RC) is a promising technology, wherein equilibrium limitations are overcome by simultaneous reaction and adsorptive separation in a single unit. This operation, on a large scale, can be performed conveniently in a simulated moving bed reactor (SMBR) in continuous mode. In this work, we demonstrate the use of an SMBR for the synthesis of 2-ethylhexyl acetate through experiments and simulations. The kinetic model and Langmuir adsorption isotherm, which serve as inputs to the simulator, were taken from an earlier study (GyaniMahajani Sep. Sci. Technol. 2008, 43, 2245). A parametric study was performed using the experimentally validated simulator by varying one of the parameters at a time, to yield desired performance in terms of conversion, purity, productivity, and desorbent consumption. The trends in the results are explained with the help of variations in the solid and liquid concentrations. The simulation results indicate that an SMBR unit containing eight columns is able to offe...

Simulated Moving Bed Reactor for the Synthesis of 2-Ethylhexyl Acetate. Part II: Simulation Based Design

A simulated moving bed reactor (SMBR) is a multifunctional reactor wherein the reaction and chromatographic separation take place simultaneously. The positions of the inlet and outlet ports are switched at periodic intervals to simulate a true moving bed system. The design exercise for these units is a challenging task due to the large number of degrees of freedom such as the column volume, SMBR configuration (i.e., number of beds in each section), sectional flow rates, switch time, desorbent concentration and feed concentration. In this work, we propose a simulation based design methodology for the SMBR process that is employed for heterogeneously catalyzed reversible reactions, in which one of the reactants works as a solvent and the catalyst also plays the role of adsorbent. The objectives are productivity (PR) maximization and desorbent consumption (DC) minimization which have a direct impact on the total annualized cost of the process. The performance parameters such as conversion, raffinate purity, ...

Liquid–liquid equilibria of water + acetic acid + 2-ethyl hexyl acetate ternary system

Liquid–liquid equilibrium (LLE) data of water+acetic acid+2-ethyl hexyl acetate have been determined experimentally at 298.2, 308.2 and 318.2K. All the phase diagrams were obtained by determining binodal curves and tie-lines. The reliability of the experimental tie-lines was confirmed by using the Othmer–Tobias correlation. UNIFAC and modified UNIFAC models were used to predict the phase equilibrium in the system determined from experimental data, using the interaction parameters between CH3, CH2, CH, CH3COO, COOH, and H2O functional groups. Distribution coefficients and separation factors were evaluated for the immiscibility region.

Chemical composition and antioxidant activity of essential oils of three endemic medicinal plants of Iran

Hydro-distillated essential oils (EO) antioxidant activity of three endemic medicinal plants of Iran namely, Heracleum lasiopetalum Boiss., Kelussia odoratissima Mozaff., and Ferulago angulata (Schlecht.) Boiss were studied. The results indicated that the major components of the EOs were 2-ethylhexyl acetate (34.5%), n-octanol (6.5%), and hexanol (5.1%) for H. lasiopetalum fruits; Z-?-ocimene (20.5), ?-pinene (11.6%), and ?-phellandrene (9.3) for F. angulata aerial parts; ?-pinene (20.1%), 1,8-cineole (18.2%), and Zligustilide (15.5%) for K. odoratissima aerial parts. The three EOs having high antioxidant activity could be used as an alternative preservative instead of synthetic ones in food industry. DOI: http://dx.doi.org/10.3329/bjb.v42i2.18038 Bangladesh J. Bot. 42(2): 327-332, 2013 (December)

Thermal Conductivity of Liquid 2-Methoxyethyl Acetate, 2-Ethylhexyl Acetate, and Diethyl Succinate

The thermal conductivity of 2-methoxyethyl acetate, 2-ethylhexyl acetate, and diethyl succinate in liquid phase was reported. The measurements of 2-methoxyethyl acetate and 2-ethylhexyl acetate, covering a temperature range from (233 to 373) K and pressure up to 20 MPa, have been performed by a transient hot-wire technique with two anodized tantalum hot wires. The measurements of diethyl succinate ranged from (263 to 383) K and atmospheric pressure to 20 MPa. The experimental data were represented by polynomial functions of pressure and temperature for the purpose of interpolation. The relative uncertainty of the present thermal conductivity data was estimated to be ± 2.0 % with a coverage factor of k = 2.

Entrainer-Based Reactive Distillation for the Synthesis of 2-Ethylhexyl Acetate

The production of 2-ethylhexyl acetate by esterification of 2-ethylhexanol with acetic acid in the presence of ion-exchange resin (Amberlyst-15) as catalyst is investigated in a reactive distillation (RD) column using toluene as an entrainer. Toluene helps in removing water efficiently from the reactive zone and maintains the reactive zone temperature below the thermal stability limit of the catalyst. Experiments as well as simulations show that quantitative conversion is achievable using the proposed entrainer-based reactive distillation process. The effect of different parameters on the conversion is studied through simulations. The proposed RD process is compared with the conventional process that uses homogeneous p-toluenesulfonic acid (pTSA) as a catalyst and it is shown that the proposed process is more energy efficient and less capital intensive.

Efficient hydrolytic reaction of an acetate ester with fungal lipase in a liquid–liquid interface bioreactor (L–L IBR) using CaCO3-coated ballooned microsphere

In a liquid-liquid interface bioreactor using a CaCO₃-coated ballooned microsphere, 2-ethylhexyl acetate was efficiently hydrolyzed to 2-ethyl-1-hexanol with Absidia coerulea NBRC 4423 compared with using talc-coated or non-coated ballooned microsphere. It was assumed that CaCO₃ brought about stabilization of lipase by Ca²⁺ and maintenance of medium pH.