Methoxyamine is the organic compound with the formula CH3ONH2. Also called O-methylhydroxylamine, it is a colourless volatile liquid that is soluble in polar organic solvent and in water. It is a derivative of hydroxylamine with the hydroxyl hydrogen replaced by a methyl group. Alternatively, it can be viewed as a derivative of methanol with the hydroxyl hydrogen replaced by an amino group. It is an isomer of N-methylhydroxylamine and aminomethanol. It decomposes in an exothermic reaction (-56 kJ/mol) to methane and azanone unless stored as a hydrochloride salt.[2]
Synthesis
Methoxyamine is prepared via O-alkylation of hydroxylamine derivatives. For example, it is obtained by O-methylation of acetone oxime followed by hydrolysis of the O-methylated oxime:[4]
- (CH3)2CNOCH3 + H2O → (CH3)2CO + H2NOCH3
The other broad method involves methanolysis of hydroxylamine sulfonates:
- H2NOSO3− + CH3OH → H2NOCH3 + HSO4−
Reactions
Analogous to the behavior of hydroxylamine, methoxyamine condenses with ketones and aldehydes to give imines.
Methoxyamine is used as a synthon for NH2+. It undergoes deprotonation by methyl lithium to give CH3ONHLi. This N-lithio derivative is attacked by organolithium compounds to give, after hydrolysis, amines:[5]
- H2NOCH3 + CH3Li → LiHNOCH3 + CH4
- LiHNOCH3 + RLi → RNHLi + LiOCH3
- RNHLi + H2O → RNH2 + LiOH
Uses
Methoxyamine has potential medicinal uses. It covalently binds to apurinic/apyrimidinic (AP) DNA damage sites and inhibits base excision repair (BER), which may result in an increase in DNA strand breaks and apoptosis.This agent may potentiate the anti-tumor activity of alkylating agents.[6]
Examples of drugs incorporating the methoxyamine unit are brasofensine and gemifloxacin.
References
- ^ International Union of Pure and Applied Chemistry (2014). Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013. The Royal Society of Chemistry. p. 994. doi:10.1039/9781849733069. ISBN 978-0-85404-182-4.
- ^ a b c Kokko, Bruce J.; Edmondson, Scott D. (14 March 2008). "O -Methylhydroxylamine". Encyclopedia of Reagents for Organic Synthesis: rm192m.pub2. doi:10.1002/047084289X.rm192m.pub2. ISBN 978-0471936237.
- ^ "O-Methylhydroxylamine". pubchem.ncbi.nlm.nih.gov.
- ^ Review: Houben-Weyl, Methoden der organische Chemie, vol 10.1, p 1186. Patent: Klein, Ulrich; Buschmann, Ernst; Keil, Michael; Goetz, Norbert; Hartmann, Horst "Process for preparing O-substituted hydroxylammonium salts." Ger. Offen. to BASF, (1994), DE 4233333 A1 19940407.
- ^ Kokko, Bruce J.; Edmondson, Scott D. (2008). "O-Methylhydroxylamine". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rm192m.pub2. ISBN 978-0471936237.
- ^ NCI