Ruthenium Complex-catalyzed Novel and Facile Synthesis of Imidazo[1,2-<i>a</i>]pyridines from 2-Aminopyridines and<i>vicinal</i>-Diols
作者:Teruyuki Kondo、Shinji Kotachi、Shin-ichi Ogino、Yoshihisa Watanabe
DOI:10.1246/cl.1993.1317
日期:1993.8
Ruthenium complex-catalyzed N-heterocyclization of 2-aminopyridines with vicinal-diols offers a novel synthetic method for various imidazo[1,2-a]pyridines. For example, the reaction of 2-amino-4-methylpyridine with 1,2-cyclohexanediol in the presence of a catalytic amount of RuCl2(PPh3)3 under reflux in diglyme for 24 h afforded 2-methyl-6,7,8,9-tetrahydropyrido[1,2-a]benzimidazole in 74% yield.
钌配合物催化下,2-氨基吡啶与邻二醇的N-杂环化反应为多种咪唑并[1,2-a]吡啶提供了新颖的合成方法。例如,在回流的二甘醇溶剂中,以催化量的RuCl2(PPh3)3为催化剂,2-氨基-4-甲基吡啶与1,2-环己二醇反应24小时,可得到产率为74%的2-甲基-6,7,8,9-四氢吡啶并[1,2-a]苯并咪唑。