Showing posts with label Acid Catalysed. Show all posts
Showing posts with label Acid Catalysed. Show all posts

Thursday, May 19, 2011

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.