Introduction of Green Chemistry Concepts into Undergraduate Chemistry Lab: A Greener Approach to Aspirin Synthesis

The synthesis of aspirin is a common undergraduate experiment conducted in general and organic chemistry labs. We hope to adapt this synthesis as part of our mini-research based experiment in second semester general chemistry lab. This synthesis requires a heating tool and uses a strong acid (sulfuric acid or phosphoric acid) as a catalyst. With the goal of introducing green chemistry concepts into the undergraduate chemistry laboratory curriculum, a MARS 6 microwave oven was introduced as a sustainable heating tool. A less hazardous synthesis is proposed converting salicylic acid into acetylsalicylic acid using the acids present in common beverages as catalysts instead of strong acid available in the chemical industry. Aspirin yields obtained were higher using the microwave compared to the ones obtained using the conventional heating method, making this method more user friendly for undergraduate labs. Aspirin products were isolated and analyzed for chemical and physical properties using Thin Layer Chromatography (TLC), melting point, Infrared Spectroscopy (IR), Nuclear Magnetic Resonance (NMR), and colorimetric analysis