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-disubstituted benzimidazoles 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
报道了一种非常简单,环保和通用的方法,该方法可通过树脂结合的六氟磷酸根离子作为催化剂,在水-甲醇(1:1)混合物中选择性合成1,2-二取代的苯并咪唑和喹喔啉。该方法对于在五环三萜类化合物Friedelin的A环上引入喹喔啉核也是有效的。还已经提出了形成二取代的苯并咪唑的合理机理。