A convenient synthesis of n-substituted 2,3-dihydro-3-oxoisothiazolo[5,4-b]pyridines in acidic conditions
A novel and convenient synthesis of N-substituted 2,3-dihydro-3-oxoisothiazolo[5,4-b]pyridines which possess potent in vitro inhibitory activity against gastric (H+/K+)-ATPase is reported. Compared with the methods reported previously, the compounds were synthesized more readily in relatively high yields by conversion of N-substituted 2-(benzyl-, 1-phenylethyl-, and benzhydrylsulfinyl)nicotinamides (17d-l) in a diluted hydrochloric acid-methanol solution at room temperature.