Ethyl isocyanate

Ethyl isocyanate
Names
	IUPAC name Isocyanatoethane
	Other names NSC 89687
Identifiers
CAS Number	109-90-0;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:85107;
ChemSpider	7731;
ECHA InfoCard	100.003.381
EC Number	203-717-9;
PubChem CID	8022;
UNII	B02YQ4MIR0;
UN number	2481 (ETHYL ISOCYANATE)
CompTox Dashboard (EPA)	DTXSID5059379;
	InChI InChI=1S/C3H5NO/c1-2-4-3-5/h2H2,1H3 Key: WUDNUHPRLBTKOJ-UHFFFAOYSA-N;
	SMILES O=C=NCC;
Properties
Chemical formula	C3H5NO
Molar mass	71.079 g·mol−1
Appearance	colourless liquid with a pungent odor
Density	0.91 g/cm3
Boiling point	59–61 °C (138–142 °F; 332–334 K)
Solubility in water	Decomposes in water
Solubility	Miscible in ethanol, ethersoluble in chlorinated and aromatic hydrocarbons
Vapor pressure	17.5 mmHg
Refractive index (nD)	1.3808 at 20 °C/D
Thermochemistry
Std enthalpy of; combustion (ΔcH⦵298)	424.5 kcal (liquid)
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H225, H301, H302, H312, H315, H319, H330, H332, H334, H335
Precautionary statements	P210, P233, P240, P241, P242, P243, P260, P264, P264+P265, P270, P271, P280, P284, P301+P316, P301+P317, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P316, P317, P319, P320, P321, P330, P332+P317, P337+P317, P342+P316, P362+P364, P370+P378, P403, P403+P233, P403+P235, P405, P501
Related compounds
Related compounds	Methyl isocyanate; Propyl isocyanate; Butyl isocyanate; Pentyl isocyanate;
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Ethyl isocyanate is an organic chemical compound of carbon, hydrogen, nitrogen and oxygen with the molecular formula C₃H₅NO.^[2] The compound belongs to the group of isocyanates. Its structural formula is CH₃—CH₂—NCO.^[3]

Synthesis

Ethyl isocyanate can be obtained by reacting triphosgene with ethylamine hydrochloride in xylene.

Ethyl isocyanate is a highly flammable, volatile, colorless liquid with a pungent odor that decomposes in water.^[4]

C₃H₅NO + H₂O → CO₂ + NH₂C₂H₅^[5]

The compound is used in the production of pharmaceuticals and pesticides.^[6]

^ ^a ^b ^c ^d ^e ^f PubChem. "Ethyl isocyanate". pubchem.ncbi.nlm.nih.gov. Retrieved 2026-01-20.
^ Roscoe, Henry Enfield (1890). A Treatise on Chemistry: The chemistry of the hydrocarbons and their derivatives, or Organic chemistry. D. Appleton and Company. p. 420. Retrieved 19 January 2026.
^ "Ethyl isocyanate". Sigma Aldrich. Retrieved 18 January 2026.
^ "ETHYL ISOCYANATE | CAMEO Chemicals | NOAA". cameochemicals.noaa.gov. Retrieved 19 January 2026.
^ Bernthsen, August (1894). A text-book of organic chemistry, tr. by G. M'Gowan. p. 279. Retrieved 19 January 2026.
^ "Ethyl isocyanate" (PDF). NJ.gov. Retrieved 19 January 2026.