Trimethylamine is an organic compound with the formula N(CH3)3. This colorless, hygroscopic, and flammable tertiary amine has a strong "fishy" odor in low concentrations and an ammonia-like odor at higher concentrations. It is a gas at room temperature but is usually sold in pressurized gas cylinders or as a 40% solution in water.
Trimethylamine is a product of decomposition of plants and animals. It is the substance mainly responsible for the odor often associated with rotting fish, some infections, bad breath and can be a cause of vaginal odor due to bacterial vaginosis. It is also associated with taking large doses of choline and carnitine.
Trimethylamine is a nitrogenous base and can be readily protonated to give trimethylammonium cation. Trimethylammonium chloride is a hygroscopic colorless solid prepared from hydrochloric acid. Trimethylamine is a good nucleophile, and this reaction is the basis of most of its applications.
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§Production
Trimethylamine is prepared by the reaction of ammonia and methanol employing a catalyst:
- 3 CH3OH + NH3 â†' (CH3)3N + 3 H2O
This reaction coproduces the other methylamines, dimethylamine (CH3)2NH and methylamine CH3NH2.
Trimethylamine has also been prepared via a reaction of ammonium chloride and paraformaldehyde, according to the following equation:
- 9 (CH2=O)n + 2n NH4Cl â†' 2n (CH3)3N•HCl + 3n H2O + 3n CO2â†'
§Applications
Trimethylamine is used in the synthesis of choline, tetramethylammonium hydroxide, plant growth regulators or herbicides, strongly basic anion exchange resins, dye leveling agents and a number of basic dyes. Gas sensors to test for fish freshness detect trimethylamine.
§Trimethylaminuria
Trimethylaminuria is a genetic disorder in which the body is unable to metabolize trimethylamine from food sources. Patients develop a characteristic fish odour of their sweat, urine, and breath after the consumption of choline-rich foods. Trimethylaminuria is an autosomal recessive disorder involving a trimethylamine oxidase deficiency. A condition similar to trimethylaminuria has also been observed in a certain breed of Rhode Island Red chicken that produces eggs with a fishy smell, especially after eating food containing a high proportion of rapeseed.
§See also
- Ammonia, NH3
- Ammonium, NH4+
- Methylamine (CH3)NH2
- Triethylamine (TEA)
§References
§External links
- Molecule of the Month: Trimethylamine
- NIST Webbook data
- CDC - NIOSH Pocket Guide to Chemical Hazards