Carboxylic Acids and their Derivatives

Here is a look at a reaction directly from our proven organic chemistry flash card system:

Esterification of Acid Chloride

Overall Big Picture: In this reaction, an acid halide is reacted with an alcohol to give an ester.

Acid Chloride + Alcohol → Ester

Key Tip: A mild base is required to drive the reaction forward.

Key Comparison: This reaction is only possible due to the high reactivity of acid halides for nucleophiles, even weak ones like alcohols.

Mechanism Hint: Collapse of the addition intermediate is propagated by deprotonating by pyridine, which helps to drive the reaction forward.

Note: When this reaction is carried out using p-toluensufonyl chloride (tosyl group), this reaction is a good protecting group for alcohols.

First window: acetyl chloride

Middle window: alcohol, pyridine

Last window: methyl ester