Amide dehydration
Abstract
The amide dehydration reaction converts a primary amide into a nitrile using a dehydrating agent (commonly SOCl2, P2O5 or POCl3) and eliminating a molecule of water.
Keywords
Amide, Thionyl chloride, Nitrile
Category
Amide
Mechanism
First, the oxygen atom of the carbonyl attacks the dehydrating agent (here, thionyl chloride), displacing a chloride ion and forming a chlorosulfite intermediate, in which the oxygen atom is now a good leaving group. Then, the previously displaced chloride ion deprotonates the nitrogen atom. Finally, the nitrogen lone pair forms a 𝜋 bond with the carbon, generating the nitrile functional group while releasing SO2 and hydrochloric acid.
