The mechanism of oxidation of hydroxamic acids by alkaline ferricyanide

Abstract

The oxidation of hydroxamic acids, RCO·NH·OH (I)via their radical-anions RCO–N–O (II) gives NO-diacylhydroxylamines RCO·NH·O·COR (III) in high yields. These compounds are active acylating agents. It is suggested that an unstable dimer of (II) gives (III) by intramolecular rearrangement.

N-Alkylhydroxamic acids oxidise similarly to give N-alkyl-NO-diacylhydroxylamines together with oximes or their oxidation products.

Both kinetic and e.s.r. studies have been used to elucidate the reaction mechanism.