Hydroxylamine

[5] Hydroxylamine was first prepared as hydroxylammonium chloride in 1865 by the German chemist Wilhelm Clemens Lossen (1838-1906); he reacted tin and hydrochloric acid in the presence of ethyl nitrate.

[11] Another route to NH2OH is the Raschig process: aqueous ammonium nitrite is reduced by HSO−3 and SO2 at 0 °C to yield a hydroxylamido-N,N-disulfonate anion: This ammonium hydroxylamine disulfonate anion is then hydrolyzed to give hydroxylammonium sulfate: Julius Tafel discovered that hydroxylamine hydrochloride or sulfate salts can be produced by electrolytic reduction of nitric acid with HCl or H2SO4 respectively:[12][13] Hydroxylamine can also be produced by the reduction of nitrous acid or potassium nitrite with bisulfite: Hydrochloric acid disproportionates nitromethane to hydroxylamine hydrochloride and carbon monoxide via the hydroxamic acid.

[citation needed] A direct lab synthesis of hydroxylamine from molecular nitrogen in water plasma was demonstrated in 2024.

Similarly to amines, one can distinguish hydroxylamines by their degree of substitution: primary, secondary and tertiary.

The hydrolysis of N-substituted oximes, hydroxamic acids, and nitrones easily provides hydroxylamines.

High concentrations of hydroxylamine are used by biologists to introduce mutations by acting as a DNA nucleobase amine-hydroxylating agent.

[23] 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.

[24] 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.

[25] Practically, it has been largely surpassed by more potent mutagens such as EMS, ENU, or nitrosoguanidine, but being a very small mutagenic compound with high specificity, it found some specialized uses such as mutation of DNA packed within bacteriophage capsids,[26] and mutation of purified DNA in vitro.

[27] An alternative industrial synthesis of paracetamol developed by Hoechst–Celanese involves the conversion of ketone to a ketoxime with hydroxylamine.

[30] Cytochrome P460, an enzyme found in the ammonia-oxidizing bacteria Nitrosomonas europea, can convert hydroxylamine to nitrous oxide, a potent greenhouse gas.

It is used as an irreversible inhibitor of the oxygen-evolving complex of photosynthesis on account of its similar structure to water.

Stereo, skeletal formula of hydroxylamine with all explicit hydrogens added
Stereo, skeletal formula of hydroxylamine with all explicit hydrogens added
Stereo, skeletal formula of hydroxylamine with all explicit hydrogens added and assorted dimensions
Stereo, skeletal formula of hydroxylamine with all explicit hydrogens added and assorted dimensions
NFPA 704 four-colored diamond Health 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroform Flammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oil Instability 3: Capable of detonation or explosive decomposition but requires a strong initiating source, must be heated under confinement before initiation, reacts explosively with water, or will detonate if severely shocked. E.g. hydrogen peroxide Special hazards (white): no code
Secondary N , N -hydroxylamine schema
Conversion of cyclohexanone to caprolactam involving the Beckmann rearrangement .
This route also involves the Beckmann Rearrangement, like the conversion from cyclohexanone to caprolactam.