text: It reacts with tertiary amines to trisubstituted hydrazinium salts and with pyridine to the 1-amino pyridinium salt.
  From 1-aminopyridinium salts the photochemically active 1-N-iminopyridinium ylides are accessible by acylation. The photochemical rearrangement of the obtained 1-N-iminipyridinium ylides leads in high yields to 1H-1,2-diazepines
  N-amination of 1H-benzotriazole with hydroxylamine-O-sulfonic acid yields a mixture of 1-aminobenzotriazole (major product) and 2-aminobenzotriazole (minor product).  From 1-aminotriazole, benzyne is formed in an almost quantitative yield by oxidation with lead(IV) acetate, which rapidly dimerizes to biphenylene in good yields.
  Electron deficient heterocycles, such as tetrazole, can be N-aminated with hydroxylamine-O-sulfonic acid, while even more electron-deficient compounds, such as 5-nitrotetrazole, react only with stronger aminating agents such as O-tosylhydroxylamine or O- mesitylene sulfonylhydroxylamine to amino compounds, which were investigated as explosives.
  In the N-amination of the unsubstituted tetrazole, a mixture of 1-amino- and 2-aminotetrazole is obtained.
  Also sulfur compounds (such as thioethers) can be aminated with hydroxylamine-O-sulfonic acid to sulfinimines (isosteric with sulfoxides but far more unstable) or phosphorus compounds (such as triphenylphosphine) can be aminated to phosphine imides via the intermediate aminotriphenylphosphonium hydrogen sulfate.
  The reaction of hydroxylamine-O-sulfonic acid with metal salts of sulfinic acids in sodium acetate solution produces primary sulfonamides in very good yields.
  Diimine can formed in situ from hydroxylamine-O-sulfonic acid respectively hydroxylamine-O-sulfonic acid hydroxylamine sulfate mixtures, which hydrogenates selectively conjugated multiple bonds.[20]