nitrophenols and benzotriazole

Weak magnetic field (WMF) and Fe(0) were proposed to activate PS synergistically (WMF-Fe(0)/PS) to degrade dyes and aromatic contaminants. The removal rates of orange G (OG) by WMF-Fe(0)/PS generally decreased with increasing initial pH (3.0-10.0) and increased with increasing Fe(0) (0.5-3.0 mM) or PS dosages (0.5-3.0 mM). Compared to its counterpart without WMF, the WMF-Fe(0)/PS process could induce a 5.4-28.2 fold enhancement in the removal rate of OG under different conditions. Moreover, the application of WMF significantly enhanced the decolorization rate and the mineralization of OG. The degradation rates of caffeine, 4-nitrophenol, benzotriazole and diuron by Fe(0)/PS were improved by 2.1-11.1 fold due to the superimposed WMF. Compared to many other sulfate radical-based advanced oxidation technologies under similar reaction conditions, WMF-Fe(0)/PS technology could degrade selected organic contaminants with much greater rates. Sulfate radical was identified to be the primary radical species responsible for the OG degradation at pH 7.0 in WMF-Fe(0)/PS process. This study unraveled that the presence of WMF accelerated the corrosion rate of Fe(0) and thus promoted the release of Fe(2+), which induced the increased production of sulfate radicals from PS and promoted the degradation of organic contaminants. Employing WMF to enhance oxidation capacity of Fe(0)/PS is a novel, efficient, promising and environmental-friendly method since it does not need extra energy and costly reagents.

Topics: Azo Compounds; Caffeine; Color; Diuron; Hydrogen-Ion Concentration; Iron; Kinetics; Magnetic Fields; Minerals; Nitrophenols; Sulfates; Triazoles; Water Pollutants, Chemical

When allylamine is used as the amino input in Ugi-Smiles couplings of o-nitrophenols, the resulting adducts can be deallylated by a palladium-catalyzed process leading to a formal Ugi-Smiles coupling with ammonia. This new sequence, combined with hydrogenolysis of the nitro group, offers an interesting multicomponent entry to benzotriazole and benzimidazole scaffolds.

Topics: Ammonia; Benzimidazoles; Catalysis; Cyanides; Molecular Structure; Nitrophenols; Oxidation-Reduction; Palladium; Triazoles