Halogenation Reaction of S-Aryl-S-[(1, 2-benzisoxazol-3-yl) methyl] sulfoximide

The reactions of the title free sulfoximide with N-bromosuccinimide (NBS) and N-chlorosuccinimide (NCS) afforded the corresponding α-halogenated"free"sulfoximides in good yields. The α-bromination proceeded via a facile N-bromination followed by a bromine transfer reaction of the resulting N-bromosulfoximide. The NCS chlorination, in contrast, proceeded via direct α-chlorination, not via N-chlorination. However, in the presence of potassium carbonate or silica gel N-chlorination occurred predominantly in the NCS chlorination.