Synthesis of 2-substituted benzimidazoles by iodine-mediated condensation of orthoesters with 1,2-phenylenediamines
作者:Zhan-Hui Zhang、Jian-Jiong Li、Yuan-Zhe Gao、Yu-Heng Liu
DOI:10.1002/jhet.5570440642
日期:2007.11
Iodine was found to be an efficient catalyst for the synthesis of 2-substitutedbenzimidazoles by the condensation of orthoesters and 1,2-phenylenediamines in good to excellent yields under mild reaction conditions.
Expeditious and Efficient Synthesis of Benzoxazoles, Benzothiazoles, Benzimidazoles Catalyzed by Ga(OTf)3 under Solvent-Free Conditions
作者:Juyan Liu、Qian Liu、Wei Xu、Weilu Wang
DOI:10.1002/cjoc.201180310
日期:2011.8
new and efficient method for the synthesis of benzoxazoles, benzothiazoles, benzimidazoles from reactions of o‐substituted aminoaromatics with orthoesters in the presence of catalytic amounts of Ga(OTf)3under solvent‐free conditions is presented. The remarkable features of this new protocol are high conversion, very short reaction times, cleaner reaction profiles under solvent‐free conditions, straight