useful reagent for the synthesis of caprolactam. The hydroxylamine-O-sulfonic acid, which should be stored at 0 °C to prevent decomposition, can be checked by iodometric titration. and N-organylhydroxylamines (R–NHOH), can be reduced to ammonia and amines , respectively, where R is an organyl group. Hydroxylamine explodes with heat: The high reactivity comes in part from the partial isomerisation of the to ammonia oxide (also known as azane oxide), with zwitterionic structure . Functional group Substituted derivatives of hydroxylamine are known. If the hydroxyl hydrogen is substituted, this is called an O-hydroxylamine, if one of the amine hydrogens is substituted, this is called an N-hydroxylamine. In general N-hydroxylamines are the more common. Similarly to ordinary amines, one can distinguish primary, secondary and tertiary hydroxylamines, the latter two referring to compounds where two or three hydrogens are substituted, respectively. Examples of compounds containing a hydroxylamine functional group are N-tert-butyl-hydroxylamine or the glycosidic bond in calicheamicin. N,O-Dimethylhydroxylamine is a coupling agent, used to synthesize Weinreb amides. Synthesis The most common method for the synthesis of substituted hydroxylamines is the oxidation of an amine with benzoyl peroxide. Some care must be taken to prevent over-oxidation to a nitrone. Other methods include: Hydrogenation of an oxime Alkylation of hydroxylamine The thermal degradation of amine oxides via the Cope reaction Uses Approximately 95% of hydroxylamine is used in the synthesis of cyclohexanone oxime, a precursor to Nylon 6. The treatment of this oxime with acid induces the Beckmann rearrangement to give caprolactam (3). The latter can then undergo a ring-opening polymerization to yield Nylon 6. Laboratory uses Hydroxylamine and its salts are commonly used as reducing agents in myriad organic and inorganic reactions. They can also act as antioxidants for fatty acids. High concentrations of hydroxylamine are used by biologists to introduce mutations by acting as a DNA nucleobase amine-hydroxylating agent. In is thought to mainly act via hydroxylation of cytidine to hydroxyaminocytidine, which is misread as thymidine, thereby inducing C:G to T:A transition mutations. But high concentrations or over-reaction of hydroxylamine in vitro are seemingly able to modify other regions of the DNA & lead to other types of mutations. This may be due to the ability of hydroxylamine to undergo uncontrolled free radical chemistry in the presence of trace metals and oxygen, in fact in the absence of its free radical affects Ernst Freese noted hydroxylamine was unable to induce reversion mutations of its