N-Sulfonylamidines. Part IV. Intramolecular Cyclization of N-Sulfonylamidines of 2-Oxoacids: a new Synthesis of 3-Aminoisothiazole S,S-dioxides

Article abstract of DOI:10.1016/S0040-4020(01)92260-4

N-alkylsulfonylamides of α-ketoacids 3 bearing both a carbonyl group and at least one H-atom near to the SO2 group give easily an intramolecular ring-closure reaction by action of potassium t-butoxide producing the 3-amino-4,5-dihydro-4-hydroxy-isothiazol