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A14916 Trimethylamine N-oxide dihydrate, 98+%

CAS Number

Stock No. Size Price ($) Quantity Availability
A14916-06 5g 31.50
A14916-14 25g 47.70
A14916-22 100g 118.00
A14916-36 500g 464.00
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Trimethylamine N-oxide dihydrate, 98+%


Chemical Properties

Formula Weight
111.14 (75.11anhy)
Melting point
Storage & Sensitivity
Hygroscopic. Ambient temperatures.
Soluble in water, ethanol, dimethyl sulfoxide and methanol. Sparingly soluble in hot chloroform. Insoluble in diethyl ether, benzene and hydrocarbon solvents.


Trimethylamine N-oxide dihydrate is used as an oxidizing agent in organic synthesis. It is also used to make quaternary ammonium compounds and a warning agent for flammable gas. Further, it acts as a flavoring agent or adjuvant. It serves as an oxidant for the catalytic osmium tetraoxide cis-hydroxylation of hindered olefins. In addition to this, it is used as a reactant for C-H bond cleavage and decarbonylating agent for solvent-free reactions.


Hygroscopic. Incompatible with acids, acid chlorides, acid anhydrides and oxidizing agents.

Literature References

Reagent for the liberation of organics from their complexes with iron carbonyls. Partial oxidation of CO to CO2 takes place: J. Chem. Soc., Chem. Commun., 336 (1974).

Also oxidizes alkylboranes to alcohols, giving less interference with other functionality than the more usual H2O2: J. Org. Chem., 40, 1776 (1975).

Has been used in the oxidation of alkyl halides to aldehydes. For a procedure, including dehydration of the N-oxide by distillation of water with DMF, see: Org. Synth. Coll., 5, 872 (1973):

For an improved procedure using DMSO, see: Tetrahedron Lett., 31, 4825 (1990).

For use as a reoxidant in the catalytic cis-hydroxylation of alkenes with Osmium(VIII)­ oxide, 12103 , see: Tetrahedron Lett., 21, 449 (1980).

Deprotonation by LDA at low temperature gives the unstable azomethine ylide, which undergoes 1,3-dipolar addition, even with unactivated alkenes, to give pyrrolidines: J. Chem. Soc., Chem. Commun., 31 (1983):

Reviews: Trimethylamine as a useful oxidizing agent: J. Prakt. Chem./ Chem. Ztg., 338, 190 (1996); The utility of N-oxides in synthesis: Synthesis, 263 (1993).

Compare also 4-Methyl­morpholine N-oxide monohydrate, A15996 .

Hunger, J.; Ottosson, N.; Mazur, K.; Bonn, M.; Bakker, H. J. Water-mediated interactions between trimethylamine-N-oxide and urea. Phys. Chem. Chem. Phys. 2015, 17 (1), 298-306.

Makarov, D. M.; Egorov, G. I.; Kolker, A. M. Density and Volumetric Properties of Aqueous Solutions of Trimethylamine N-Oxide in the Temperature Range from (278.15 to 323.15) K and at Pressures up to 100 MPa. J. Chem. Eng. Data 2015, 60 (5), 1291-1299.

GHS Hazard and Precautionary Statements

Hazard Statements: H315-H319

Causes skin irritation. Causes serious eye irritation.

Precautionary Statements: P264b-P280-P302+P352-P305+P351+P338-P332+P313-P337+P313-P362

Wash face, hands and any exposed skin thoroughly after handling Wear protective gloves/protective clothing/eye protection/face protection. IF ON SKIN: Wash with plenty of soap and water. IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing. If skin irritation occurs: Get medical advice/attention. If eye irritation persists: Take off contaminated clothing and wash before reuse.

Other References

Harmonized Tariff Code


  • A14547

    p-Toluenesulfonyl chloride, 98%
  • A15806

    Nitrosonium tetrafluoroborate, 98%
  • A19802

    4-Methylmorpholine N-oxide, 50% w/w aq. soln.
  • L09658

    Tetramethylammonium hydroxide pentahydrate, 98%
  • L13174

    Dibenzoyl peroxide, 97% (dry wt.), wet with 25% water

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