Triethylamine is the chemical compound with the formula N(CH₂CH₃)₃, commonly abbreviated Et₃N. It is also abbreviated TEA, yet this abbreviation must be used carefully to avoid confusion with triethanolamine or tetraethylammonium, for which TEA is also a common abbreviation.
Triethylamine is the chemical compound with the formula N(CH2CH3)3, commonly abbreviated Et3N. It is also abbreviated TEA, yet this abbreviation must be used carefully to avoid confusion with triethanolamine or tetraethylammonium, for which TEA is also a common abbreviation. It is a colourless volatile liquid with a strong fishy odor reminiscent of ammonia and is also the smell of the hawthorn plant.[7] Like diisopropylethylamine (Hünig’s base), triethylamine is commonly employed in organic synthesis.
Contents
1 Synthesis and properties
2 Applications
2.1 Niche uses
3 References
4 External links
Synthesis and properties
Triethylamine is prepared by the alkylation of ammonia with ethanol:[8]
NH3 + 3 C2H5OH → N(C2H5)3 + 3 H2O
The pKa of protonated triethylamine is 10.75,[3] and it can be used to prepare buffer solutions at that pH. The hydrochloride salt, triethylamine hydrochloride (triethylammonium chloride), is a colorless, odorless, and hygroscopic powder, which decomposes when heated to 261 °C.
Laboratory samples of triethylamine can be purified by distilling from calcium hydride.[9]
Applications
Triethylamine is commonly employed in organic synthesis as a base. For example, it is commonly used as a base during the preparation of esters and amides from acyl chlorides.[10] Such reactions lead to the production of hydrogen chloride which combines with triethylamine to form the salt triethylamine hydrochloride, commonly called triethylammonium chloride. This reaction removes the hydrogen chloride from the reaction mixture, which can be required for these reactions to proceed to completion (R, R' = alkyl, aryl):
R2NH + R'C(O)Cl + Et3N → R'C(O)NR2 + Et3NH+Cl−
Like other tertiary amines, it catalyzes the formation of urethane foams and epoxy resins. It is also useful in dehydrohalogenation reactions and Swern oxidations.
Triethylamine is readily alkylated to give the corresponding quaternary ammonium salt:
RI + Et3N → Et3NR+I−
Triethylamine is mainly used in the production of quaternary ammonium compounds for textile auxiliaries and quaternary ammonium salts of dyes. It is also a catalyst and acid neutralizer for condensation reactions and is useful as an intermediate for manufacturing medicines, pesticides and other chemicals.
Niche uses
Triethylamine is used to give salts of various carboxylic acid-containing pesticides, e.g. Triclopyr and 2,4-dichlorophenoxyacetic acid[citation needed]
Triethylamine is the active ingredient in FlyNap, a product for anesthetizing Drosophila melanogaster.[citation needed] Triethylamine is used in mosquito and vector control labs to anesthetize mosquitoes. This is done to preserve any viral material that might be present during species identification.