Synthesis of new 1,5-diaryl-3-(arylamino)-1H-pyrrol-2(5H)-ones under catalyst-free and solvent-free conditions

Several new 1,5-diaryl-3-(arylamino)-1H-pyrrol-2(5H)-ones were synthesized via the three-component condensation reaction of aldehydes, aromatic amines, and ethyl pyruvate under catalyst-free and solvent-free conditions. Also, 5-(4-hydroxyl-3-nitrophenyl)-1-(4-methoxy-phenyl)-3-(4-methoxyphenylamino)-1,5-dihydro-pyrrol-2-one was synthesized using oxime instead of aldehyde. The eco-friendly, simple procedure, green procedure, catalyst-free and solvent-free conditions, short reaction times, and high yields of the products are the advantages of this method.     

Ion‐flotation Separation of Cd(II), Co(II) and Pb(II) Traces Using a New Ligand before Their Flame Atomic Absorption Spectrometric Determinations in Colored Hair and Dryer Agents of Paint

A simple, rapid and inexpensive method for separation and preconcentration of some traces of hazardous elements is presented prior to their flame atomic absorption spectrometric determinations. At pH 6.5; cadmium(II), cobalt(II) and lead(II) were separated simultaneously with 1,2‐bis((1H‐benzo[d]imidazol2‐yl)methoxy)benzene (BBIMB) as a new complexing agent and floated after adding sodium dodecyl sulfate (SDS) as a foaming reagent. The floated layer was then eluted by concentrated nitric acid in methanol and introduced to the flame atomic absorption spectrometer (FAAS). The effects of pH, concentration of BBIMB, type and amount of surfactant as the floating agent, type and amount of eluting agent and influence of foreign ions on the recoveries of the analyte ions were investigated. Also, by using a non‐linear curve fitting method the formation constants of Cd(II), Co(II) and Pb(II) complexes were obtained 1.02 × 10⁶, 1.17 × 10⁶ and 1.46 × 10⁶, respectively. The detection limits of Cd(II), Co(II) and Pb(II) ions were 1.2, 0.7 and 0.5 μg/L, respectively. The enrichment factors were 45.0, 42.0 and 39.0 for Cd(II), Co(II) and Pb(II) ions, respectively. The proposed procedure was then successfully applied for determination of those heavy metals in colored human hair and dryer agents of paint samples.     

三溴异氰脲酸和DABCI-Br作为高效催化剂用于羟基硅烷化

The protection and deprotection of functionalgroups are indispensable in the synthesis of polyfunc-tional compounds.In addition,several chemical con-versions and multiple sequence syntheses are often re-quired for the protection of hydroxyl groups.Thesily…     

PEG‐N2O4 System as an Efficient Reagent both for the Rapid Oxidation of Urazoles and 1,4‐Dihydropyridines under Nonaqueous Conditions

N₂O₄ was easily impregnated on polyethyleneglycol to give a stable reagent. Polyethyleneglycol‐N₂O₄ ( PEG‐N₂O₄ ) system was used as an effective oxidizing agent for the oxidation of urazoles and bis‐urazoles to their corresponding triazolinediones and also for the aromatization of 1,4‐dihydropyridines into the corresponding pyridine derivatives under mild conditions at room temperature with good to excellent yields.     

Silica-bonded S-Sulfonic Acid: A Recyclable Catalyst for the Synthesis of Trisubstituted Imidazoles under Solvent-free Conditions

Trisubstituted imidazoles have been synthesized in high yields in the presence of silica‐bonded S‐sulfonic acid as a catalyst. The reaction was carried out at 130°C under solvent‐free conditions. The reaction work‐up is simple and the catalyst is easily separated from the products by filtration.