Low‐valent titanium induced reductive cyclization of nitro compounds and aliphatic ketones: facile synthesis of 3, 4‐dihydro(2H)‐1, 2, 4‐benzothiadiazine‐1, 1‐dioxides

Abstract

The intermolecular reductive cyclization of o‐nitrobenzene‐sulfonamides with aliphatic ketones induced by TiCl4/Sm system was studied and a series of 3, 3‐disubstituted‐3,4‐dihydro(2H)‐1,2, 4‐benzothiadiazine‐1,1‐dioxides were synthesized in moderate to high yields under mild and neutral conditions.