Ethylamine
Properties
| State | Gas (colorless with strong fishy/ammoniacal odor; liquid below 17°C) |
| Color | Colorless |
| Solubility | Miscible with water; miscible with ethanol and ether |
| Melting Point | -81°C |
| Boiling Point | 17°C |
About Ethylamine
Ethylamine is the simplest primary alkylamine that's still gaseous at room temperature, boiling at 17°C — barely above ambient on a warm day, which is why a poorly sealed cylinder will announce itself to anyone within fifty meters. The smell is the classic amine signature: fishy, ammoniacal, and detectable somewhere around 0.05 ppm, far below any toxicity threshold. Ethylamine is moderately basic, with a pKaH of about 10.7, slightly stronger than ammonia because the ethyl group donates electron density to nitrogen. In aqueous solution it protonates fully to give the ethylammonium cation, and that's where most of its synthetic utility starts — as a nucleophile or as a precursor to imines, amides, and ureas. Industrially it's made by the vapor-phase reaction of ethanol with ammonia over a fixed-bed alumina or silica-alumina catalyst around 350°C, which kicks out a mixture of mono-, di-, and triethylamine that has to be separated by distillation. The biggest single end use historically has been atrazine production: ethylamine and isopropylamine both attack cyanuric chloride in a controlled stepwise SNAr sequence to build the triazine ring. Ethylamine also turns up in pharmaceutical synthesis whenever a small basic side chain is needed, and as a building block for rubber accelerators of the dithiocarbamate family.
Where you'll encounter it
If you've ever opened an old bottle of fish sauce or walked past a tannery downwind, you've smelled the family of compounds ethylamine belongs to. In a process plant, the giveaway for an ethylamine leak isn't the gas detector — it's that the operator on the next unit complains about the smell ten minutes before the alarm trips. Lab-scale, ethylamine is usually delivered as a 70% aqueous solution or a 2 M solution in THF for synthetic work, because handling the neat gas requires a Schlenk line and a fume hood you trust.
Common Uses
- Precursor to atrazine and simazine herbicides via SNAr on cyanuric chloride
- Reductive amination substrate for N-ethyl pharmaceutical intermediates
- Building block for rubber-vulcanization accelerators (dithiocarbamates)
- Imine and Schiff-base formation with aldehydes for chiral-auxiliary work
- Quaternization substrate for cationic surfactants and ion-exchange resins
- Solvent and base in selected SN2 alkylation reactions
Safety Information
GHS: H220 extremely flammable gas, H314 causes severe skin burns and eye damage, H332 harmful if inhaled. ACGIH TLV-TWA 5 ppm, OSHA PEL 10 ppm TWA. Flammable range in air is 3.5–14%, with autoignition at 385°C. The 70% aqueous solution is corrosive and reacts vigorously with strong acids — exotherms that have caused glassware failures on lab scale. Always vent reactions with ethylamine gas through a scrubber containing dilute H2SO4. Respiratory protection (supplied air, not cartridge) for any work with the neat gas above bench scale.
This safety summary is for educational reference only and may not be complete. It is not a substitute for Safety Data Sheets (SDS), medical advice, or professional chemical safety guidance. Always consult appropriate SDS and qualified professionals before handling chemicals.