Potassium superoxide stoechiometrically reacts with arylamidoximes with the selective formation of the corresponding benzamide and nitrogen oxides (mainly NO2−) in high yield. A similar oxidative cleavage of the C NOH bond of N-hydroxy-arylguanidines also occurs upon reaction with KO2; the yield of the corresponding urea is lower and large amounts of the corresponding cyanamide are also formed. The significance of this reaction of O2•− ...