Aspirin synthesis involves the addition of an acetyl group to salicylic acid in a condensation reaction with an alcohol. The acetyl group could be added with a carboxylic acid but the preferred procedure is to use the acid anhydride. Why is preferable to use an acid anhydride for ester formation with an alcohol rather than a carboxylic acid

See explanation

Explanation:

The synthesis of asprin involves the;

i) Hydrolysis of Methyl salicylate

ii) Reaction of salicylic acid with acid anhydride

The chemical name of asprin is acetylsalicylic acid.

It is preferable to use an acid anhydride for ester formation with an alcohol rather than a carboxylic acid because we will not produce water which can then cause the hydrolysis of the newly formed ester.