<i>N</i>-Substituted pyrrole synthesis by Paal-Knorr condensation using recyclable cationic exchange resin in water
作者:Yan-Hong He、Gang-Qiang Wang、Zhi Guan
DOI:10.1002/jhet.317
日期:——
Cationicexchangeresin has been utilized for the first time as a novel and recyclable heterogeneous catalyst for the synthesis of N‐substituted pyrroles from variety of 1,4‐diketones and aniline. This simple synthesis has been accomplished with excellent yields. The recovered catalyst can be reused for subsequent runs with only a gradual decrease in activity. J. Heterocyclic Chem., (2010).
1-butyl-3-methyl-imidazolium hydrogen sulfate, [bmim]HSO4, was used as a catalyst and reaction medium for the pyrrolesynthesis, and a wide range of aliphatic, aromatic, heteroaromatic and carboxylic 1,4-diketones easily underwent condensations with aniline and ethylenediamine to form polysubstituted pyrroles. Sequential decarboxylation/Paal-Knorrpyrrolecondensation was observed, which provides a new