Alcohols – Reaction with Acyl Chlorides
Specification Reference Organic Chemistry, Hydroxy compounds 32.1
Quick Notes
- Alcohols react with acyl chlorides to form esters and hydrogen chloride gas.
- The reaction is fast and produces a sweet-smelling ester.
- Example: Ethanol + Ethanoyl chloride → Ethyl ethanoate + HCl
- No catalyst is required. The reaction is vigorous and exothermic.
Full Notes
Alcohols react with acyl chlorides in nucleophilic addition–elimination reactions.
The alcohol acts as a nucleophile and attacks the partially positive carbon in the acyl chloride.
General Equation
Alcohol + Acyl chloride → Ester + HCl
Example Reaction of ethanol with ethanoyl chloride
Ethanol + Ethanoyl chloride → Ethyl ethanoate + Hydrogen chloride
CH3CH2OH + CH3COCl → CH3COOCH2CH3 + HCl
The product, ethyl ethanoate, is a colourless liquid with a fruity smell.
Conditions
- Room temperature
- No catalyst required
- Carried out in dry conditions (acyl chlorides are very reactive with water)
Key Features of the Reaction
- Faster and more vigorous than esterification with carboxylic acids.
- Used in lab preparations for making esters quickly and with high yield.
- HCl gas is corrosive and fumes in moist air – proper ventilation is needed.
Summary
- Alcohols react with acyl chlorides to form esters and HCl gas.
- The reaction is nucleophilic addition–elimination.
- Reaction is fast, vigorous, and exothermic meaning no catalyst required.
- Commonly used in lab to make esters quickly with high yield.