|Chapter 20: Carboxylic Acid Derivatives. Nucleophilic Acyl Substitution|
Hydrolysis of Amides
An acid/base reaction. Since we only have a weak nucleophile and apoor electrophile we need to activate the amide. Protonation of the amidecarbonyl makes it more electrophilic.
The water O functions as the nucleophile attacking the electrophilicCin the C=O, with the electrons moving towards the oxonium ion, creatingthe tetrahedral intermediate.
An acid/base reaction. Deprotonate the oxygen that came from the watermolecule to neutralise the charge.
An acid/base reaction. Need to make the -NH2leave, but need to convert it into a good leaving group first byprotonation.
Use the electrons of an adjacent oxygen to help "push out" the leavinggroup, a neutral ammonia molecule.
An acid/base reaction. Deprotonation of the oxonium ion reveals thecarbonyl in the carboxylic acid product and regenerates the acid catalyst.
|© Dr. Ian Hunt, Department of Chemistry|