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 RuCl 2 (PPh 3) 3 under reflux in diglyme for 24 h afforded 2-methyl-6, 7, 8, 9- tetrahydropyrido [1, 2-a] benzimidazole in 74% yield.
![2,3-dimethylimidazo[1,2-a]pyridine Structure](https://image.chemsrc.com/caspic/475/875-80-9.png)
