An efficient sulfuryl fluoride‐enabled synthesis of benzo e 1,2,3oxathiazine‐4(3 H )‐one‐2,2‐dioxides from salicylic amides is described. Salicylamides were prepared on a multigram scale, and the corresponding cyclic sulfamates were synthesized via operationally simple one‐pot Et 3 N‐promoted 5 + 1 cyclization. In some cases, intermediate products of O ‐sulfonylation (fluorosulfates) were isolated. The method was suitable for both primary and secondary salicylic amides, albeit the use of a stronger base was necessary for sterically hindered substrates. The synthetic utility of the obtained heterocycles was demonstrated by their further chemical transformations. In particular, 4‐chloro derivatives were obtained by deoxochlorination and converted into various cyclic aminosulfamates on a multigram scale. Derivatives bearing a bromine atom in the benzene ring were subjected to Pd‐catalyzed couplings without affecting the sulfamate ring. Physicochemical properties of a representative virtual library derived from the synthesized scaffolds met the criteria of lead‐likeness guidelines.
Sidorska et al. (Mon,) studied this question.