Butyl isocyanate is an organic chemical compound of carbon, hydrogen, nitrogen, and oxygen with the linear formula . This is the butyl ester of isocyanic acid.
Butyl isocyanate is usually produced by the reaction between n-butylamine and phosgene.
Butyl isocyanate is a highly reactive chemical compound. Like isocyanic acid and other isocyanates, it is highly toxic. Butyl isocyanate polymerizes upon heating.
The compound forms colourless, tear-inducing liquid with a pungent odor.
Propyl isocyanate decomposes in water, alcohols, and acids. Also decomposes on burning. Butyl isocyanate can be anionically polymerized into poly(butyl isocyanate) when lanthanum isopropoxide is used as the initiator.
The compound is used in production of other chemicals.