Various imidazo- and triazolo-pyridines were synthesised by the intramolecular cyclization of pyridine 2-methylamine and dithioesters under mild conditions.
A vital approach of Fe(OTf)3 and MS3Å (molecular sieves 3Å) mediated one pot synthesis of 1,3-disubstituted imidazo[1,5-a]pyridines from dithioester, 2-methylaminopyridine and alcohol. This methodology involves the intramolecular cyclization and C–C bond formation under mild condition and operates in a single step yielding the products in good to excellent yields. This protocol was compatible to construct various 1,3-disubstituted imidazo[1,5-a] pyridines derivatives.