The anticoagulant racemic warfarin is synthesized by the Michael addition of 4-hydroxycoumarin with benzalacetone in the present of equimolar amounts of imidazolium based ionic liquids [bmim] BF4 and [bmim] Br and other reaction solvents such as H2O, pyridine and ammonia in five different tests. Also synthesis of a derivative of warfarin (2-methyl-4-phenyl pyrano [3, 2-c] chromen-5(4H)-one) und...

A fast, simple and environmentally friendly ultrasound-assisted dispersive liquid-liquid microextraction (USA-DLLME) procedure has been developed to preconcentrate eight cyclic and linear siloxanes from wastewater samples prior to quantification by gas chromatography-mass spectrometry (GC-MS). A two-stage multivariate optimization approach has been developed employing a Plackett-Burman design f...

In this paper, a simple dispersive liquid-liquid microextraction for the extraction and pre-concentration of formaldehyde in seawater samples followed with spectrophotometric is proposed. Formaldehyde was derivatized in situ with acetyl acetone in the presence of ammonium acetate in a single step. Then it was collected into a mixture of ethanol (disperser solvent) and chloroform (extracting...

Solid-phase microextraction (SPME) coupled to high-performance liquid chromatography (HPLC) has been applied to the analysis of priority pollutant phenolic compounds in water samples. Two types of polar fibers [50 microm Carbowax-templated resin (CW-TPR) and 60 microm polydimethylsiloxane-divinylbenzene (PDMS-DVB)] were evaluated. The effects of equilibration time and ionic strength of samples ...

a simple and mild procedure for the conversion of anilines into aryl isocyanates is described using the 3-hydroxypropylammonium acetate (hpaa) ionic liquid as a novel and efficient media has been explored in the synthesis of aryl isocyanates from the reaction of substituted urea with sodium nitrite in a water immiscible solvent. this ionic liquid can be easily recovered and reused for many time...

The anticoagulant racemic warfarin is synthesized by the Michael addition of 4-hydroxycoumarin with benzalacetone in the present of equimolar amounts of imidazolium based ionic liquids [bmim] BF4 and [bmim] Br and other reaction solvents such as H2O, pyridine and ammonia in five different tests. Also synthesis of a derivative of warfarin (2-methyl-4-phenyl pyrano [3, 2-c] chromen-5(4H)-one) und...

a simple and rapid microextraction procedure based on dispersive liquid-liquid microextraction (dllme) was developed for determination and speciation of trace amounts of chromium (cr) by flame atomic absorption spectrometry (faas). in the proposed approach, chloroform and methanol were used as extraction and dispersive solvents. a new schiff's base ligand, bis(2-methoxy benzaldehyde) ethylene d...

An in-situ reactor was elaborately designed for O-alkylation of chitosan in an ionic liquid ([BMIM]Cl) solvent, using N, N'-carbonyldiimidazole as bonding agent. The original chitosan and the modified chitosan were characterized by FT-IR and XRD analysis. FT-IR spectra revealed that the alkylation of chitosan selectively occurred at hydroxyl groups, with unprotected amino groups untouched. It w...

A simple and homogeneous green liquid–liquid microextraction based on temperature-controlled ionic liquid (IL) process was developed for the selective extraction spectrophotometric analysis of zinc (II) ethylenebis (dithiocarbamate) (zineb) from different foodstuff samples including rice, wheat, corn, oat, cabbage, potato, tomato grain. The effect various parameters like pH, IL dose, temperatur...