Synthesis of functionalized benzimidazoles and quinoxalines catalyzed by sodium hexafluorophosphate bound Amberlite resin in aqueous medium
作者:Pranab Ghosh、Amitava Mandal
DOI:10.1016/j.tetlet.2012.09.045
日期:2012.11
for the selective synthesis of 1,2-disubstitutedbenzimidazoles and quinoxalines in water–methanol (1:1) mixture with the aid of resin bound hexafluorophosphate ion as catalyst is reported. The method is also effective for the incorporation of quinoxaline nucleus at the A ring of pentacyclic triterpenoid, friedelin. A plausible mechanism for the formation of disubstituted benzimidazole has also been suggested
Catalytic role of sodium dodecyl sulfate: Selective synthesis of 1, 2-disubstituted benzimidazoles in water
作者:Pranab Ghosh、Amitava Mandal
DOI:10.1016/j.catcom.2011.01.005
日期:2011.3
A simple and efficient procedure for the synthesis of 1, 2-disubstituted benzimidazoles has been developed by a one-pot reaction of o-phenylenediamine with both aromatic and aliphatic aldehydes in the presence of sodiumdodecylsulfate in aqueousmedium at roomtemperature in open air without any organic solvent. The surfactant is recycled. A plausible mechanistic approach has also been suggested.
Highly selective synthesis of libraries of 1,2-disubstituted benzimidazoles using silica gel soaked with ferric sulfate
作者:Susmita Paul、Basudeb Basu
DOI:10.1016/j.tetlet.2012.05.129
日期:2012.8
An efficient and highly selective synthesis of functionalized 1,2-benzimidazoles has been developed under solvent-free conditions at ambient temperature using eco-friendly ferric sulfate soaked with silica [iron(III)sulfate–silica]. Recycling of the solid support up to six runs was investigated with appreciable yield and selectivity of the product.
γ-Maghemite-silica nanocomposite: A green catalyst for diverse aromatic N-heterocycles
作者:Pranab Ghosh、Amitava Mandal、Raju Subba
DOI:10.1016/j.catcom.2013.06.026
日期:2013.11
gamma-Maghemite-silica nanocomposite has been applied as a green catalyst to synthesize variety of aromatic N-heterocycles under solvent free conditions. Characterization was done by modern analytical tools (UV, IR, AAS, DSC, EDXRF, powdered XRD, EPR, Mossbauer and TEM). Mild reaction conditions and recyclability have made the present protocol both environmentally and economically viable. (c) 2013 Elsevier B.V. All rights reserved.