An efficient,rapid and facile procedure for conversion of aldoximes to nitriles using triphenylphosphine and N-halo sulfonamides

N,N,N＇,N＇-Tetrabromobenzene-1,3-disulfonamide （TBBDA）/triphenylphosphine and N,N,N＇,N＇-tetra- chlorobenzene-1,3-disulfonamide （TCBDA）/triphenylphosphine have been introduced as highly efficient systems for the versatile conversion of aldoxime derivatives into nitriles. The process reported here is operationally simple and reactions have been mildly performed in dichloromethane at room temperature.     

A novel one-pot synthesis of some new interesting pyrrole derivatives

[reaction: see text] 11-(1H-Pyrrol-1-yl)-11H-indeno[1,2-b]quinoxaline and 3-(1H-pyrrol-1-yl)indolin-2-one derivatives have been synthesized in good yields in a novel, one-pot, and efficient process by condensation of 11H-indeno[1,2-b]quinoxalin-11-one or isatin derivatives with 4-hydroxyproline on solid-support montmorillonite K10 under microwave irradiation.     

Synthesis of phosphonato esters involving heterocyclic biological bases in a highly diastereoselective and chemoselective route

Abstract  

Synthesis of five phosphonato esters has been accomplished via reaction between dimethyl acetylenedicarboxylate and triphenyl phosphite in the presence of biological compounds such as theophylline, 4-hydroxypyrimidine, 2H-3,1-benzoxazine-2,4(1H)-dione, 2-chloroaniline, or 3-nitroaniline at ambient temperature. The configuration of the compounds was determined on the basis of coupling constants emerging from the Karplus equation.     

Biotransformation of some monoterpenoid ketones by <Emphasis Type="Italic">Chlorella vulgaris</Emphasis> MCCS 012

Biotransformation of several monoterpene ketones, including carvone, pulegone, piperitone, menthone, and fenchone, was carried out by the locally isolated unicellular microalgae Chlorella vulgaris. The microalgal strain was isolated during a screening program from soil samples collected from paddy-fields of Fars Province, in the south of Iran. Chlorella vulgaris was cultured in 250 mL conical flasks, each containing 50 mL of BG-11 liquid medium and 20 μL levels of terpene substrates, incubated at a temperature of 28±2°C and illuminated continuously with fluorescent lamps with shaking at 80 rpm. The metabolites were identified by thin-layer chromatography and GC-MS. Chlorella vulgaris has the ability to reduce the C=C double bond of carvone to yield trans-dihydrocarvone and cis-dihydrocarvone. The cell line reduced menthone and pulegone to the same product and gave menthol. Study of Chlorella vulgaris with substrates of piperitone and fenchone showed no reaction in these substrates. Chlorella vulgaris MCCS 012 was assigned according to the 18S rRNA gene sequence. The DNA sequence of the 18S rRNA gene of Chlorella vulgaris MCCS 012 was recorded in the NCBI under the accession number EU374170.     

Simultaneous extraction and preconcentration of copper,silver and palladium with modified alumina and their determination by electrothermal atomic absorption spectrometry

In the present work,an easy solid phase extraction method using alumina modified with polyethylenimine as a new adsorbent was applied to the simultaneous extraction of copper,silver,and palladium ions prior to their determination with electrothermal atomic absorption spectrometry.The analytical procedure involved the complex formation of these cations with polyethylenimine as a chelating agent in buffer media of pH 7.0.Under the optimum conditions,a preconcentration factor of200,150,and 200,precision of ±5.4%,±4.7%,and ±5.2%and linear calibration ranges of 15.0-140,4.0-93,and 7.5-125 ng/L(in original solution) for Cu,Ag,and Pd were obtained,respectively.Also detection limits of3.9,1.1,and 2.0 ng/L were obtained for Cu,Ag,and Pd,respectively.The proposed method was applied to the determination of copper,silver,and palladium in some real samples with satisfactory results.     

Site‐Selective Oxidation of Monolayered Liquid‐Exfoliated WS2 by Shielding the Basal Plane through Adsorption of a Facial Amphiphile

In recent years, various functionalization strategies for transition‐metal dichalcogenides have been explored to tailor the properties of materials and to provide anchor points for the fabrication of hybrid structures. Herein, new insights into the role of the surfactant in functionalization reactions are described. Using the spontaneous reaction of WS₂ with chloroauric acid as a model reaction, the regioselective formation of gold nanoparticles on WS₂ is shown to be heavily dependent on the surfactant employed. A simple model is developed to explain the role of the chosen surfactant in this heterogeneous functionalization reaction. The surfactant coverage is identified as the crucial element that governs the dominant reaction pathway and therefore can severely alter the reaction outcome. This study shows the general importance of the surfactant choice and how detrimental or beneficial a certain surfactant can be to the desired functionalization.     

A Switch in the Hydrophobic/Hydrophilic Gas-Adsorption Character of Prussian Blue Analogues: An Affinity Control for Smart Gas Sorption

Porous coordination polymers are molecule-based materials presenting a high degree of tunability, which offer many advantages for targeted applications over conventional inorganic materials. This work demonstrates that the hydrophilic/hydrophobic character of Prussian blue analogues having a lipophilic feature may be tuned to optimize the gas adsorption properties. The role of the coordinatively unsaturated metal sites is emphasized through a combination of theoretical and experimental study of water, ethanol, and n-hexane adsorption.     

Sorptive thin film microextraction followed by direct solid state spectrofluorimetry: A simple,rapid and sensitive method for determination of carvedilol in human plasma

A poly acrylate-ethylene glycol (PA-EG) thin film is introduced for the first time as a novel polar sorbent for sorptive extraction method coupled directly to solid-state spectrofluorimetry without the necessity of a desorption step. The structure, polarity, fluorescence property and extraction performance of the developed thin film were investigated systematically. Carvedilol was used as the model analyte to evaluate the proposed method. The entire procedure involved one-step extraction of carvedilol from plasma using PA-EG thin film sorptive phase without protein precipitation. Extraction variables were studied in order to establish the best experimental conditions. Optimum extraction conditions were the followings: stirring speed of 1000 rpm, pH of 6.8, extraction temperature of 60 °C, and extraction time of 60 min. Under optimal conditions, extraction of carvedilol was carried out in spiked human plasma; and the linear range of calibration curve was 15–300 ng mL⁻¹ with regression coefficient of 0.998. Limit of detection (LOD) for the method was 4.5 ng mL⁻¹. The intra- and inter-day accuracy and precision of the proposed method were evaluated in plasma sample spiked with three concentration levels of carvedilol; yielding a recovery of 91–112% and relative standard deviation of less than 8%, respectively. The established procedure was successfully applied for quantification of carvedilol in plasma sample of a volunteer patient. The developed PA-EG thin film sorptive phase followed by solid-state spectrofluorimetric method provides a simple, rapid and sensitive approach for the analysis of carvedilol in human plasma.     

Synthesis of Hexahydrospiro[pyrazolo[3,4‐b]quinoline‐4,1′‐pyrrolo[3,2,1‐ij]quinoline‐2′,5(1H,4′H)‐diones] from 5,6‐dihydro‐4H‐pyrrolo[3,2,1‐ij]quinoline‐1,2‐dione Using Fe3O4@Cu(OH)x as a Nanocatalyst

The tricyclic isatin, 5,6‐dihydro‐4H‐pyrrolo[3,2,1‐ij]quinoline‐1,2‐dione, undergoes three‐component, one‐pot reactions with 1‐aryl‐3‐methylpyrazole‐5‐amines and cyclohexane‐1,3‐diones producing hexacyclic spiro products, hexahydrospiro[pyrazolo[3,4‐b]quinoline‐4,1‐pyrrolo[3,2,1‐ij]quinoline‐2′,5(1H,4′H)‐diones]. Comparable spiro condensation products are also obtained using 4‐hydroxy‐2H‐1‐benzopyran‐2‐one in place of cyclohexane‐1,3‐diones.     

Numerical analysis of the internal flow and the mixing chamber length effects on the liquid film thickness exiting from the effervescent atomizer

Journal of Thermal Analysis and Calorimetry - Two-phase flow was simulated within the effervescent atomizer by the volume of fluid interface tracing model. Different gas-to-liquid mass ratios...