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

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.