The oxidation of hydroxamic acids

Abstract

The oxidation of alkyl or benzyl N-hydroxycarbamate produced mainly the corresponding O-alkoxycarbonyl or O-benzoxycarbonyl N-hydroxycarbamates and small amounts of the corresponding trisubstituted hydroxylamines. The oxidation of sodium benzhydroxamate with iodine gave O-benzoyl benzhydroxamate; hydroxyurea and N-hydroxy-N′-phenylurea were similarly converted into N-carbamoyloxyurea and N-hydroxy-N′-phenyl-N-phenylcarbamoylurea, respectively. Oxidation of ethyl, n-propyl, and benzyl N-hydroxycarbamates or hydroxyurea of N-hydroxy-N-phenylurea with iodine in aqueous ammonium carbonate gave the corresponding carbamates, urea, or phenylurea. With silver oxide in ether, alkyl N-hydroxycarbamates and their O-alkoxycarbonyl derivatives yielded N-silver-N-alkoxycarbonyloxycarbamates; simulataneous oxidation of ethyl and benzyl N-hydroxycarbamates gave NO-di- and NNO-tri-substituted hydroxylamines in which the substituents were ethoxycarbonyl, benzyloxycarbonyl, or, possibly, ethyl and benzyl groups.