Alkyl Ethyl Research Articles

Cholinesterase Aging Phenomenon Following Acute Ethoprophos Poisoning: A Case Report

Background: Acute poisoning by Ethoprphos, an organophosphorus pesticide, leads to a veritable cholinergic syndrome whose diagnosis is based on the determination of cholinesterase activity. The treatment relies on the administration of atropine and pralidoxime to regenerate cholinesterases before their ageing. Case: We report a case of a two-year-old child, hospitalized for ethoprophos poisoning, with seizures associated with tight myosis, bronchial congestion, fever, and sialorrhea. The determination of butyrylcholinesterase and acetylcholinesterase showed low rates throughout the hospitalization. Knowing that pralidoxime was introduced from the 5th day of the poisoning, these rates could be explained by aging of cholinesterases. This phenomenon is well established for organophosphate pesticides (OPs) with methylated or ethyl alkyl groups in contrast to others that are much less documented such as dipropyled OPs such as ethoprophos. The recovery of the enzyme rates was very slow with good clinical improvement. Conclusion: Ethoprophos poisoning may cause a life-threatening prognosis with a possible phenomenon of cholinesterase aging in the absence of rapid management with administration of pralidoxime.

Ultrasound-assisted cloud point microextraction of certain preservatives in real samples and determination by HPLC.

Ultrasound-assisted cloud point microextraction (UA-CPME) was performed for certain preservatives (p-hydroxy benzoic acid and its alkyl esters, methyl, ethyl, propyl and butyl parabens). Then, an HPLC method was developed for their simultaneous determination in pharmaceutical and cosmetic samples. The chromatograms of these substances were recorded on a C18 column using a gradient elution technique with various solvent systems at different flow rates and at 254 nm wavelength using a diode-array detector (DAD). The analysis conditions found by the classical method were optimized using the Box-Behnken design (BBD). In the design, the effect of each factor was examined with 3 and 4 factors for UA-CPME and HPLC analyses, respectively. The brij 58 concentration (BC), Na2SO4 amount (SA) and extraction time (ET) for UA-CPME, and the mobile phase 1 (MP1) ratio, mobile phase 2 (MP2) ratio, flow rate (FR) and column temperature parameters for HPLC analysis were obtained for the investigated levels. The factors affecting the resolution were determined by applying regression analysis to the experimental results. The analysis of variance (ANOVA) test was applied to ensure result reliability. The ANOVA test was used to determine the reliability of the results. A model was created with the obtained data. The developed method was validated by examining linearity, reproducibility, accuracy, limit of quantification and limit of the detection. Methyl paraben (with 0.148% RSD value and 0.060% relative error), and propyl paraben (with 0.149% RSD value and 0.120% relative error) were determined in the syrup sample by the developed method. Methyl paraben with recovery values of (98.32-99.42)% and ethyl paraben with recovery values of (99.17-99.41)%, were determined in a hand cream.

Copolymers incorporated with \u03b2-substituted acrylate synthesized by organo-catalyzed group-transfer polymerization

Various copolymers incorporated with β-substituted acrylates, such as alkyl crotonates (e.g., methyl crotonate (MC), ethyl crotonate (EC), isopropyl crotonate (iPC), and n-butyl crotonate (nBC)) and methyl cinnamate (MCin), were synthesized by group-transfer polymerization (GTP) using a silicon-based Lewis acid catalyst. In addition to β-substituted acrylates, α-substituted acrylates (e.g., methyl methacrylate (MMA) and n-butyl methacrylate (nBMA)) were examined as comonomers. Proton nuclear magnetic resonance (1H NMR) spectroscopy and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) characterizations of the obtained copolymers revealed that each monomer component was incorporated sufficiently. The thermal stabilities of the resulting copolymers were investigated by dynamic mechanical analysis (DMA), indicating that the glass-transition temperature (Tg) of the copolymers can be widely varied over a relatively high-temperature range by selecting the optimal comonomer. More specifically, the Tg values of poly(MC-random-EC) (MC/EC molar ratio = 50/50), poly(MC-random-nBC) (MC/nBC molar ratio = 50/50), poly(MC-random-MCin) (MC/MCin molar ratio = 54/46), and poly(nBC-random-MCin) (nBC/MCin molar ratio = 56/44) were 173, 130, 216, and 167 °C, respectively.

SYNTHESIS OF NITROMETHYL-, N -METHYLINDOLYL-, OR N -METHYLINDOLYLNITROMETHYL- SUBSTITUTED 1,4-BENZOTHIAZIN(DIAZIN)ONES AND 3-METHYL-1,4-BENZOXAZINONES FROM ALKYL 3-NITROACRYLATES

На основе реакций алкил-3-нитроакрилатов и этил-2-(1-метил-1H-индол-3-ил)-3-нитроакрилата с о-аминотиофенолом, о-аминофенолом, о-фенилендиамином и их аналогами осуществлен синтез и изучено строение 2-(нитрометил)-2H-1,4-бензотиазин-3(4H)-она, 2-(1-метил-1H-индол-3-ил)-2-(нитрометил)-2H-1,4-бензотиазин-3(4H)-она, 3-метил-2H-1,4-бензоксазин-2-онов и 3-(1-метил-1H-индол-3-ил)хиноксалин-2(1H)-онов.

Application of Ultrasonic Cavitation in the Etherification Reaction of a Coker Naphtha Narrow-Cut Fraction with Ethanol

The effect of ultrasonic cavitation on the process of etherification of a coker-naphtha light fraction (IBP–85°C) with ethanol using an HCl-treated zeolite catalyst has been studied. Optimal process conditions have been determined to be T = 80°C, P = 0.2 MPa, and Vspace = 0.5 h-1, under which the olefin conversion and the yield of alkyl ethyl ethers increase by 12.1 and 5.6%, respectively, and the motor octane number of the etherification product is enhanced by 6 points, with catalyst coking being reduced by 50–55%.

Effects of alkyl ethyl sulfonate dosage on cotton defoliation efficacy sprayed by UAV

Abstract: As a new low volume sprayer, unmanned aerial vehicle (UAV) application is developing quickly worldwide. Alkyl ethyl sulfonate soluble concentrate is a kind of spray adjuvants for defoliants, which is widely used in cotton defoliant application. The aim of this study was to compare the droplet deposition, defoliation and boll opening of a UAV added with six dosages of alkyl ethyl sulfonate on the cotton. Addition with 4.2 g a.i./hm 2 (one-sixtieth of the recommended dosage in the field) alkyl ethyl sulfonate could significantly increase the droplets coverage rate, and improve defoliation and boll opening effects. Added with lower dosage alkyl ethyl sulfonate (4.2 g a.i./hm 2 and 8.4 g a.i./hm 2 ), the droplet distribution uniformity was much better than that of moderate (84 g a.i./hm 2 ) and high dosage (252 a.i./hm 2 ) of alkyl ethyl sulfonate. It could not only ensure the effects of defoliation and boll opening, but also reduce the environmental pollution by alkyl ethyl sulfonate. Keywords: defoliant, alkyl ethyl sulfonate dosage, droplet deposition, unmanned aerial vehicle DOI:  10.33440/j.ijpaa.20190202.33.  Citation: Xiao Q G, Du R, Zhou T T, Han X Q, Wang G B, Fu W. Effects of alkyl ethyl sulfonate dosage on cotton defoliation efficacy sprayed by UAV.  Int J Precis Agric Aviat, 2019; 2(2): 67–75.

Effect of Non-reactive Powder Particle Properties on Dry Agglomeration in a High Shear Mixer

The effect of non-reactive powder particle properties on the detergent dry agglomeration process in a high shear mixer was investigated. Three types of micron-scale silica were chosen as the non-reactive fine powders and a semi-solid alkyl ethyl ethoxy sulfate (AES) paste with ultra-high viscosity was chosen as the binder. The granules were characterized using mass-based granule size distribution, scanning electron microcopy, and bulk density tests. The results revealed that powder particle size plays a leading role in agglomeration behavior. A decrease in the median particle size results in enhanced dispersion of silica particles in the AES paste binder droplets, which leads to the formation of uniform granules that are slightly affected by compacting forces. Agglomerate quality, using silica with high oil absorption as well as optimum particle size, was satisfactory, and the product exhibited a smaller median particle size, narrower size distribution, and superior anti-caking capacity under the same liquid-to-solid ratio (L/S).

A synthesis of functionalized 2,5-diimino-thiazolidines from Nef-isocyanide adduct and 1-alkyl-3-arylthioureas

GRAPHICAL ABSTRACT

ChemInform Abstract: One‐Pot Synthesis of β,β‐Disubstituted α,β‐Unsaturated Carbonyl Compounds.

AbstractMethyl alkyl and aryl ketones undergo TiCl4‐mediated aldol reaction in good yields and with high E selectivity.

Towards new 5-HT7 antagonists among arylsulfonamide derivatives of (aryloxy)ethyl-alkyl amines: Multiobjective based design, synthesis, and antidepressant and anxiolytic properties

A series of 39 arylsulfonamide/amide derivatives of (aryloxy)ethyl alkyl amines, was designed with the support of the Virtual Combinatorial Library-Virtual Screening protocol, and synthesized using solid-phase methodologies. Representative compounds were biologically evaluated for their affinity for 5-HT7Rs and for their selectivity over related 5-HTRs (5-HT1ARs, 5-HT2ARs, 5-HT6Rs), dopamine D2Rs and adrenergic α1Rs. The study identified the derivatives 27 (3-fluoro-N-{1-[2-(2-cyclopentylphenoxy)ethyl]piperidin-4-yl}-benzenesulfonamide; PZ-1417) and 35 (4-fluoro-N-(1-{2-[(propan-2-yl)phenoxy]ethyl}-8-azabicyclo[3.2.1]octan-3-yl)-benzenesulfonamide; PZ-1150) as being potent 5-HT7R antagonists with antidepressant and anxiolytic properties in the forced swim test (0.625–5 mg/kg and 0.625 mg/kg, respectively), the tail suspension test (0.625 mg/kg and 0.625 mg/kg, respectively), and in four plate test (0.625 mg/kg and 1.25–2.5 mg/kg, respectively) in mice. It has to be stressed that new compounds displayed higher activity than that of SB-269970, a reference 5-HT7R antagonist. Finally, the study provided valuable insight into the development of potential therapeutic agents for the treatment of CNS disorders.

Structural identification of petroleum acids by conversion to hydrocarbons and multidimensional gas chromatography-mass spectrometry.

Identification of individual petroleum acids ("naphthenic" acids, NA) has proved challenging for decades, due to the extreme complexity of many petroleum acid mixtures. This has hindered detailed understanding of the role of NA in petroleum generation and oil production processes, refinery corrosion, as wood preservatives, and as environmental toxicants. Some recent advances have been made due to improved chromatographic separation of esters of the acids by multidimensional gas chromatography-mass spectrometry (GC × GC-MS), but relatively few reference spectra of esters are available for comparison. Here we report a complementary method based on a combination of a modified historical approach of converting NA to the corresponding hydrocarbons, followed by analysis by GC × GC-MS. Many published spectra exist for reference hydrocarbons making comparisons of reference spectra with those of the unknowns, much more feasible. As an example, we report identification of over 30 individual bicyclic naphthenic acids as the bicyclane hydrocarbons. These include both fused and bridged acids possessing methyl, dimethyl, and ethyl alkyl substituents as well as some terpenoid-derived acids. The study provides the most comprehensive analysis of one of the major classes of NA (the bicyclic acids) to date. There is now clear potential for this method to be used for the structural elucidation of other unknown acids (e.g., oil sands acids) and functionalized biomarkers in complex mixtures.

Synthesis of Bicyclic Isoxazoles and Isoxazolines via Intramolecular Nitrile Oxide Cycloaddition.

An efficient and straight forward procedure for the syntheses of bicyclic isoxazole/isoxazoline derivatives from the corresponding dimethyl-2-(2-nitro-1-aryl/alkyl)-2-(prop-2-yn-1yl)malonates or dimethyl 2-allyl-2-(2-nitro-1-aryl/alkyl ethyl)malonate is described. High yields and simple operations are important features of this methodology.

Fragmentation mechanisms in mass spectrometry of organophosphorus compounds: implications for analysis in chemical weapons convention framework

Detection and identification of chemical warfare agents and their precursors/reaction products in various environmental matrices are important tasks which are considered in chemical weapons convention (CWC). 2-[(2-chloroethyl)(alkyl)amino]ethyl alkyl methylphosphonates I and N-alkyl bis(2-(alkoxy-methylphosphoryloxy)amines II are covered under schedule 2.B.4 of CWC and have structures closely related to the nerve and blister agents. In fact, they are products of the reactions between these two different CWC scheduled compounds: nerve agents and nitrogen mustards. Ion fragmentations during mass spectrometry studies of these chemicals were investigated using electron ionization mass spectrometry. Structures of fragments were confirmed using EI-MS analysis of the deuterated analogs. Density functional theory was also used to show preferred fragmentation pathways. Mass spectrometric studies revealed some fragmentation pathways, such as, McLafferty-type and hydrogen rearrangements and elimination of chlorine, chloromethylene radical, alkene and HCl.

Synthesis of the Mixed Alkyl Esters of Phenylphosphonic Acid by Two Variations of the Atherton–Todd Protocol

ABSTRACTPhenylphosphonates with mixed alkyl groups were synthesized from ethyl phenyl‐H‐phosphinate by two modified Atherton–Todd methods. Using aqueous sodium hydroxide under phase transfer catalytic conditions, the alkyl ethyl phosphonates were obtained in only moderate yields. However, applying 1‐methylimidazole as the base, the diesters could be prepared in yields of 76–85%. The imidazole hydrochloride formed as a by‐product acts as an ionic liquid phase in the reaction, from which the base can be regenerated.

Chiral phosphoric-acid-catalyzed transfer hydrogenation of ethyl ketimine derivatives by using benzothiazoline.

Chiral phosphoric acid catalyzed transfer hydrogenation of ketimines derived from propiophenone derivatives and reductive amination of alkyl ethyl ketone derivatives were extensively examined in the presence of two representative hydrogen donors. The excellent enantioselective transfer hydrogenation was achieved by use of benzothiazoline as a hydrogen donor. The theoretical studies elucidated that the unsymmetrical structure of benzothiazoline plays an important role in high enantioselective hydrogenation.

Study of extraction systems based on the mixtures of phosphorylated calix[4,6]arenes with dioctyl sulfide for recovery of triaquatrinitrorhodium species from acid nitrate-nitrite solutions

A comparison was made for extraction systems based on the mixtures of calix[n]arenes phosphorylated at the upper and lower rims (PCA, n = 4 and 6) with dioctyl sulfide (DOS) for recovery of rhodium in the form of [Rh(H2O)3(NO2)3]0 from acid nitrate-nitrite media. Because of inertness of rhodium compounds, the main attention was devoted to extraction kinetics. The kinetic efficiency of DOS + PCA systems was found to be much higher than that for DOS alone, whereas the components of the mixtures do not extract rhodium. Alkyl(ethyl)calixphosphine oxides are the most promising, they behave as accelerating additives in extractant mixtures. Extraction kinetics of [Rh(H2O)3(NO2)3]0 species was studied and extraction systems were selected to develop method for the recovery of fission rhodium.

Colloidal ZnO nanocrystals in dimethylsulfoxide: a new synthesis, optical, photo- and electroluminescent properties

Stable colloidal solutions of zinc oxide in dimethylsulfoxide were synthesized via interaction between zinc(II) acetate and tetraalkylammonium hydroxides (alkyl–ethyl, propyl, butyl, and pentyl). Colloids of ZnO emit photoluminescence in a broad band with a maximum at 2.3–2.4 eV with quantum yields of up to 9–10% at room temperature and 15–16% at 80 K. The photoluminescence is supposed to originate from the radiative recombination of conduction band electrons with holes captured by deep traps having corresponding states in the band gap 1.0–1.2 eV above the valence band edge. The size of colloidal ZnO nanocrystals depends on the duration and temperature of the post-synthesis treatment and varies in the range of 3–6 nm. Growth of the ZnO nanocrystals can be terminated at any moment of the thermal treatment by freezing the colloidal solution or by addition of tetraethyl orthosilicate which hydrolyses forming core–shell ZnO@SiO2 particles. ZnO nanocrystals introduced into polyethyleneimine films can be used as an active component of an LED emitting at an applied voltage higher than 13 V.

A library of spectral patterns as a tool for the rapid and reliable identification of highly toxic O-alkyl-S-2-(N,N-dialkylamino)ethyl alkyl thiophosphonates based on electron-ionization mass spectra

A rapid and reliable method for group identification based on the fragmentation of highly toxic O-alkyl-S-2-(N,N-dialkylamino)ethyl alkyl thiophosphonates using electron-ionization mass spectra was proposed. This method makes it possible to relate a test substance to one of the four groups of compounds containing two identical alkyl substituents at the nitrogen atom (methyl, ethyl, propyl, or isopropyl). The essence of this method is that the mass spectrum of the test substance is compared with the generalized mass-spectrometric patterns of each of the four groups of this class with the aid of a standard procedure utilized in the NIST information retrieval program.

ChemInform Abstract: Chemistry of 9,10‐Phenanthrenequinone Revisited: Iron(III) Chloride Catalyzed Reactions of 9,10‐Phenanthrenequinone with Acyclic and Cyclic Ketones Provide Furan Annulated Products.

9,10-Phenanthrenequinone (PQ) reacts with ketones under FeCl3 catalysis to furnish a variety of structurally diverse furan annulated products. While the reaction of PQ with acetone and cyclopentanone furnishes furan annulated ketals, its reaction with ethyl alkyl ketones provides 3-furaldehyde annulated products. In contrast to the reaction of PQ with cyclopentanone, its reaction with cyclohexanone furnishes a tetrahydrobenzofuran annulated secondary alcohol. The reactions of PQ with cycloheptanone and cyclooctanone take a different course to provide 7,8-dihydro-6H-cyclohepta[b]furan and 6,7,8,9-tetrahydrocycloocta[b]furan annulated products, respectively. Mechanistically, the above reactions go through aldol condensation, dehydration and cyclization to form furan-phenanthrene annulated products where in each step FeCl3 catalysis is involved.

Ion chromatographic separation and quantitation of alkyl methylamines and ethylamines in atmospheric gas and particulate matter using preconcentration and suppressed conductivity detection

Two methods based on ion chromatography (IC) were developed for the detection of methyl and ethyl alkyl amines (methylamine (MA), ethylamine (EA), dimethylamine (DMA), diethylamine (DEA), trimethylamine (TMA) and triethylamine (TEA)) and NH3/NH4+ in online atmospheric gas-particle and size-resolved particulate samples. The two IC methods were developed to analyze samples collected with an ambient ion monitor (AIM), an online gas-particle collection system, or with a Micro Orifice Uniform Deposit Impactor (MOUDI) for size-resolved particle samples. These methods enable selective and (semi-) quantitative detection of alkyl amines at ambient atmospheric concentrations (pptv and pgm−3) in samples where significant interferences can be expected from Na+ and NH4+, for example marine and rural air masses. Sample pre-concentration using a trace cation column enabled instrumental detection limits on the order of pmol (sub-ng) levels per sample, an improvement of up to 102 over current IC methods. Separation was achieved using a methanesulfonic acid gradient elution on Dionex CS12A and CS17 columns. The relative standard deviations in retention times during 3weeks continuous (hourly) sampling campaigns ranged from 0.1 to 0.5% and 0.2 to 5% for the CS12A and CS17 across a wide dynamic range of atmospheric concentrations. Resolution of inorganic and organic cations is limited to 25min for online samples. Mass-dependent coelution of NH4+/MA/EA occurred on the CS12A column and DEA/TMA coeluted on both columns. Calibrations of ammonium show a non-linear response across the entire calibration range while all other analytes exhibit high linearity (R2=0.984–0.999), except for EA and TEA on the CS12A (R2=0.960 and 0.941, respectively). Both methods have high analytical accuracy for the nitrogenous bases ranging from 9.5 to 20% for NH3 and <5–15% for the amines. Hourly observations of amines at Egbert, ON in October 2010 showed gaseous DMA and TMA+DEA at 1–10pptv in air, while particulate DMA and TMA+DEA were present at 0.5–4ngm−3. A size-resolved particulate sample collected over 23h was found to contain DMA, TMA+DEA and MEA at 1.78, 8.15 and 0.03ngm−3 mass loadings, with the amine mass enhanced in particle sizes between 100 and 1000nm. These results highlight a need for very sensitive and selective detection of methyl and ethyl amines in addition to NH3 in continuous online monitoring strategies.