Rearrangement of differentially protected N-arylhydroxylamines

The rearrangement of a series of N,O-difunctionalized N-arylhydroxylamines to generate protected 2-aminophenols has been investigated. N-Boc-N-aryl-O-acylhydroxylamines are stable, isolable compds. which rearrange smoothly at temps. between 110 and 140°C. The corresponding N-Boc-N-aryl-O-sulfonylhydroxylamines were not isolated and rearrange to 1,2-difunctionalized aminophenols at room temp. in excellent yield. Deprotection of either the N- or O-substituents under std. conditions allows for further synthetic manipulation of either the aniline or phenol functionality.