Bondline / Reactions

Hydrolysis of an acyl chloride

Even water is nucleophilic enough to attack an acyl chloride. Addition, then elimination of chloride, gives the carboxylic acid and HCl (steamy fumes).

Acyl substitution · 3 steps

Conditions

Water, room temperature. Vigorous; acyl chlorides must be kept dry.

Mechanism in 3 steps

Red curly arrows show where each pair of electrons moves.

H2OOClO−ClOH2++
Step 1Water attacks the carbonyl carbon.
O−ClOH2+OH+HOH2O+
Step 2The C=O reforms and chloride leaves.
OH+HOH2OOOHH3O+H₂O++
Step 3Water removes the proton, giving the carboxylic acid.

About acyl substitution reactions

Carboxylic acid derivatives react by nucleophilic addition followed by elimination: the nucleophile adds to C=O, then the leaving group is expelled and the C=O reforms.

Practise this mechanismDraw the curly arrows yourself and Bondline checks each one. Or add it to your notes and watch it in 3D.

Open in Bondline