N-Methylmorpholine N-oxide: Difference between revisions

{{chembox

| verifiedrevid = 444021270

| Name=''N''-Methylmorpholine ''N''-oxide

| ImageFileL1 = NMO.png

| ImageSizeL1 = 100px

| ImageFileR1 = N-methylmorpholine-N-oxide-3D-balls.png

| ImageSizeR1 = 120px

| IUPACName =

| OtherNames =

| Section1 = {{Chembox Identifiers

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| ChemSpiderID = 74032

| InChI = 1/C5H11NO2/c1-6(7)2-4-8-5-3-6/h2-5H2,1H3

| InChIKey = LFTLOKWAGJYHHR-UHFFFAOYAV

| StdInChI_Ref = {{stdinchicite|correct|chemspider}}

| StdInChI = 1S/C5H11NO2/c1-6(7)2-4-8-5-3-6/h2-5H2,1H3

| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}

| StdInChIKey = LFTLOKWAGJYHHR-UHFFFAOYSA-N

| CASNo_Ref = {{cascite|correct|CAS}}

| CASNo = 7529-22-8

| PubChem = 82029

| ChEBI_Ref = {{ebicite|correct|EBI}}

| ChEBI = 52093

| SMILES = C[N+]1(CCOCC1)[O-]

| Section2 = {{Chembox Properties

| Formula = C₅H₁₁NO₂

| MolarMass = 117.15 g/mol

| Appearance =

| Density =

| MeltingPt = 180 - 184 °C

| BoilingPt =

| Solubility =

}}

| Section3 = {{Chembox Hazards

| MainHazards =

| FlashPt =

| Autoignition =

}}

'''''N''-Methylmorpholine-''N''-oxide''', '''NMO''' or '''NMMO''' is an [[organic compound]]. This [[heterocycle|heterocyclic]] [[amine oxide]] and [[morpholine]] derivative is used in [[organic chemistry]] as a co-oxidant and [[sacrificial catalyst]] in [[organic oxidation|oxidation]] reactions for instance in [[osmium tetroxide]] oxidations and the [[Sharpless asymmetric dihydroxylation]] or oxidations with [[Tetrapropylammonium perruthenate|TPAP]]. NMO is commercially supplied both as a [[monohydrate]] C₅H₁₁NO₂.H₂O and as

the anhydrous compound. The monohydrate is used as a [[solvent]] for [[cellulose]] in the [[Lyocell]] process to produce [[cellulose fiber]]s.

NMMO monohydrate is used as a [[solvent]] in the [[Lyocell]] process to produce Tencel fiber. It dissolves cellulose to form a solution called dope, and the cellulose is reprecipitated in a water bath to produce a fiber. The process is similar but not analogous to the [[viscose]] process. In the viscose process, cellulose is converted to cellulose [[xanthate]] to dissolve it. With NMMO monohydrate, cellulose is not derivatized, but directly solvated to form a homogeneous polymer solution. The resulting fiber is similar to [[viscose]]; this was observed, for example, for [[Valonia oak|Valonia]] cellulose microfibrils. As water is used to cause the precipitation, the solvation of cellulose with NMMO is a water sensitive process.<ref>Noé, Pierre, and Henri Chanzy "Swelling of Valonia cellulose microfibrils in amine oxide systems." Canadian Journal of Chemistry Volume 86 issue 6 pages 520-524(2008). retrieved [http://search.ebscohost.com/ EBSCO], Advanced Placement Source. 11 Nov. 2009.</ref>

Cellulose remains insoluble to most solvents since it has a strong and highly structured intermolecular hydrogen bonding network, which resists common solvents. NMMO is able to break the hydrogen bonding network that keeps cellulose insoluble to water and other solvents. Similar solubility has been obtained in a few solvents, particularly a mix of [[lithium chloride]] in [[dimethyl acetamide]] and some hydrophilic [[ionic liquid]]s.

[[Image:hexapeptide-NMO attack.png|thumb|right|400px|Hydrogen bonding between hexapeptide and NMO<ref name="Sashina 2008"/>]]

Another use of NMO is in the dissolution of [[scleroprotein]] (found in animal tissue). This dissolution occurs in the crystal areas which are more homogeneous and contain [[glycine]] and [[alanine]] residues with a small number of other residues. How NMO dissolves these proteins is scarcely studied. Other studies, however, have been done in similar [[amide]] systems (i.e. [[hexapeptide]]). The [[hydrogen bonds]] of the amides can be broken by NMO.<ref name="Sashina 2008">E. S. Sashina, N. P. Novoselov, S. V.Toroshekova, V. E. Petrenko, “Quantum-chemical study of the mechanism of dissolution of scleroproteins in N-methylmorpholine N-oxide.” Russian Journal of General Chemistry volume78 issue 1 pages 139-145 (2008). retrieved [http://search.ebscohost.com/ EBSCO], Advanced Placement Source. 11 Nov. 2009.</ref>

== Oxidant ==

[[Image:NMO example.gif|left|frame|Oxidation of an [[alkene]] with [[osmium tetroxide]] (0.06 eq.) and NMO (1.2 eq.)in [[acetone]]/water 5:1 [[room temperature|RT]] 12 hrs.<ref>''Preparation of 3H-Pyrrolo[2,3-c]isoquinolines and 3H-Pyrrolo[2,3-c][2,6]- and 3H-Pyrrolo[2,3-c][1,7]-naphthyridines'' U. Narasimha Rao, Xuemei Han and Edward R. Biehl [[Arkivoc]] '''2002''' (x) 61-66 [http://www.arkat-usa.org/ark/journal/2002/I10_General/2-562J/2-562J.pdf Online Article]</ref>]]

NMO, as a [[N-oxide]], is an oxidant. It is used as a stoichiometric oxidant to regenerate the main catalyst after the main catalyst has been reduced by the substrate. For example, the toxic and volatile [[osmium tetroxide]] needs to be added in stoichiometric amounts to effect dihydroxylation, but if continuously regenerated with NMO, the amount can be reduced to [[catalytic]] quantities.

<references/>

[[Category:Morpholines]]

[[de:N-Methylmorpholin-N-oxid]]

[[ja:N-メチルモルホリン N-オキシド]]

[[pt:N-óxido de N-metilmorfolina]]

[[sv:N-Metylmorfolin-N-oxid]]