Ruthenium Complex-catalyzed Novel and Facile Synthesis of Imidazopyridines from 2-Aminopyridines and vicinal-Diols

Article abstract of DOI:10.1246/cl.1993.1317

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 74percent yield.