Synthesis of novel isothiazolo[4,3-b]pyridine and isothiazolo[4,3-b]quinoline derivatives

Abstract The efficient synthesis of isothiazolo[4,3- b ]pyridines and isothiazolo[4,3- b ]quinolines via intramolecular vicarious nucleophilic substitution of hydrogen in N -oxides and quaternary salts of chloromethanesulfonamides derived from 3-aminopyridine and 3-aminoquinoline is described.