Effect of Temperature on the Purity and Yield of Aspirin

Abstract

Acetylsalicylic acid (aspirin) is a popular over-the-counter medication possessing anti-inflammatory and antipyretic properties. Given the large amount of aspirin manufactured annually worldwide, any modification of the manufacturing process that could increase its yield or purity would have industrial implications. In this study, we prepared aspirin through the esterification of salicylic acid with acetyl anhydride in the presence of phosphoric acid over a duration of 20 min while varying the temperature from 50 to 80 °C at 10 °C intervals. We observed increases in the percentage purity and yield of 1.25-and 1.28-fold, respectively, upon increasing the temperature from 50 to 80 °C at intervals. Linear relationships existed in the yield and purity of the synthetic aspirin, with both increasing upon increasing reaction temperature.