Synthesis of Benzo[ e ][1,4,3]oxathiazin-3-one 1-Oxides from N H- S -(2-Hydroxyaryl)sulfoximines.

Cyclizations of N H- S -(2-hydroxyaryl)sulfoximines with 1,1'-carbonyldiimidazol (CDI) give unprecedented benzo[ e ][1,4,3]oxathiazin-3-one 1-oxides in good yields. The standard synthetic protocol involves the use of DCE at an increased temperature for 16 h. Under mechanochemical conditions, a representative product was obtained without a solvent at ambient temperature in only 60 min. X-ray single-crystal structure analysis confirmed the molecular scaffold representing a three-dimensional heterocycle.