108361-83-7 Isothiazolo(5,4-b)pyridine-2(3H)-acetic acid, 4,6-dimethyl-3-oxo-, methyl ester, 1,1-dioxide Methyl 4,6-dimethyl-3-oxoisothiazolo(5,4-b)pyridine-2(3H)-acetate 1,1-dioxide