Why it is important to heat and reflux for 30-40minutes in aspirin?

Question

what are the benefits of heating and refluxing on the purity of the product?

Answer 1

I take it you are synthesizing aspirin.  You'll get more answers if you ask this in the chemistry forum, but:

You're acetylating with acetic anhydride, right?  The heat and reflux make the acetylation proceed faster.  Without heating, the reaction would not be as fast, nor as complete.  You get higher yield and higher purity.

DK