Synthesis of 1H-1-alkyl-8-X-2,2-dioxoisothiazolo[5,4,3-d,e]-quinolines via tandem cyclization of N-alkyl-N-(2-X-5-nitrophenyl)prop-2-enyl sulfonamides

Tandem five- and six-membered ring closure reactions to afford tricyclic sultams from N-alkyl-N-(2-X-5-nitrophenyl) prop-2-enyl sulfonamides is described.