Why is sulfuric acid used in the synthesis of aspirin?

Question

Why is sulfuric acid used in the synthesis of aspirin?

Answer 1

It is used as a source of protons (H+) for use as a catalyst during the esterification of the alcohol group from salicylic acid, with acetic anhydride.

This method is used in undergraduate teaching labs, because it is a simple reaction to perform. In industry there are likely to be other methods that do not use sulphuric acid, due to the public not wanting to take drugs made with a strong acid like this, although it would be perfectly safe to do so.

Hope this helps.

Al.

Answer 2

Sulfuric acid is an acid catalyst and dehydrant.