Complexes with 3-(pyridin-2-yl)imidazo[1,5-a]pyridine ligands by spontaneous dimerization of pyridine-2-carboxaldehyde within the coordination sphere of manganese(II) in a one-pot reaction.

Condensation of two molecules of pyridine-2-carboxaldehyde (pyca), in the presence of MnCl(2) and ammonium diethyldithiophosphate, produced, in a one-pot reaction, Mn(II) complexes containing 3-(pyridin-2-yl)imidazo[1,5-a]pyridines as κ(2)(N,N) chelate ligands which could be easily separated from the metal, this being a convenient way to pyridyl-aza-indolizine heterocycles.