BASE-CATALYZED REARRANGEMENT OF 2-NITROBENZENESULFENANILIDES . AN INTRAMOLECULAR OXYGEN TRANSFER PROCESS

The rearrangement of 2-nitrobenzenesulfenanilide (1a) and its 4′-methoxy derivative (1b) to the azo-benzenesulfinates (2) in aqueous alcoholic sodium hydroxide has been examined. The reactions are first order in sulfenanilide and in hydroxide ion, and 1b rearranges at a slightly faster rate than 1a. 18O-Labeling studies show that transfer of both oxygens from the nitro group to the sulfur atom takes place. These observations, and the failure of the 4 ′-nitro isomer (1c) to rearrange, are rationalized in terms of an intramolecular oxygen transfer mechanism. © 1969, American Chemical Society. All rights reserved.