Condensation of: Lppropriat. e ketoaldehydeu with 5-substituted L', I-disulfan~ ylanilirles under ac3id c% t: tlysia provided n group of B-substitut, ed 3, 4-dihydro-2H-l,~, 4-l, enzclthiadiazine-7-sulf1:~ namide 1, l-dioxides containing: I-ketoalkyl substituents. When 0- ketoaldehydes were used arid the 2-sulfamgl group was at least monosnilstituted, either the usual ring-closure products or isomeric enol-mils were isolated depending on reaction ...