Return to Contents  Chapter 20: Carboxylic Acid Derivatives. Nucleophilic Acyl Substitution  Ch 20 contents

Hydrolysis of Amides

hydrolysis of amides
Reaction type:  Nucleophilic Acyl Substitution

Summary

Related Reactions Reaction under ACIDIC conditions:
MECHANISM OF THE ACID CATALYSED HYDROLYSIS OF AMIDES
Step 1:
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.
hydrolysis of an ester with acid catalysis
Step 2:
The water O functions as the nucleophile attacking the electrophilicCin the C=O, with the electrons moving towards the oxonium ion, creatingthe tetrahedral intermediate.
Step 3:
An acid/base reaction. Deprotonate the oxygen that came from the watermolecule to neutralise the charge.
Step 4:
An acid/base reaction. Need to make the -NH2leave, but need to convert it into a good leaving group first byprotonation.
Step 5:
Use the electrons of an adjacent oxygen to help "push out" the leavinggroup, a neutral ammonia molecule.
Step 6:
An acid/base reaction. Deprotonation of the oxonium ion reveals thecarbonyl in the carboxylic acid product and regenerates the acid catalyst.
 

previous page
next page
© Dr. Ian Hunt, Department of Chemistry, University of Calgary