Treatment of amines with 1-(4-nitrophenol)-N-(O-benzylhydroxy) carbamate yields the O- benzyl protected N-hydroxyureas. Hydrogenation of the O-benzyl protected N-hydroxyureas over 5% Pd/BaSO4 cleanly gives the N-hydroxyureas in good yield. In addition to primary and secondary aliphatic and aromatic amines, this method converts amino sugars to the corresponding N-hydroxyureas without extensive protecting group chemistry.
