Iodine-mediated oxidative N-S bond formation: a facile one-pot synthetic approach to 1,2,4-benzothiadiazine 1,1-dioxides under transition metal-free conditions

Benzothiadiazine 1,1-dioxide derivatives are widely used because of their diverse biological activities and medicinal prospects. In this study, iodine-oxone mediated oxidative N-S bond formation reaction was described. This new and transition-metal-free approach allows for the convenient synthesis of a variety of 1,2,4-benzothiadiazine 1,1-dioxides from readily available urea derivatives under very mild conditions without using expensive reagents and catalysts. Further, this protocol allows for the development of a library of key building blocks with potential medical applications.