But-3-enoic acid
But-3-enoic acid is a short-chain unsaturated carboxylic acid, with the linear formula.
Synthesis
The acid is obtained via a reaction of allyl cyanide and concentrated hydrochloric acid. The mixture is gently heated with occasional shaking. The reaction produces a voluminous precipitate of ammonium chloride. Then water is introduced, and the upper acid layer is separated.Other methods are also known.
Properties
The acid forms a clear light yellow liquid. Causes skin burns.The compound is well-soluble in water, ethanol, and diethyl ether.