Aspirin – Synthesis and Analysis
For Student Groups
Acetylsalicylic acid, the variant of the anti-inflammatory natural drug salicylic acid, was marketed in 1899 by Bayer under the name ASPIRIN®. In this course, the students synthesize the substance, and – as in industrial production – perform purity checks using various analytical methods.
- 16 to 20 years
- 1 to 2 days
- Maximum number of participants
- Synthesis of acetylsalicylic acid
- Identification by thin-layer chromatography
- Detection and photometric determination of salicylic acid contamination
- Possible Extension: Acid-base titration of acetylsalicylic acid and salicylic acid instead of photometry
- Possible Extension: HPLC (High-performance liquid chromatography, MS (mass spectrometry), H-NMR (proton magnetic resonance)
The synthesis of acetylsalicylic acid refers to the simple, but in chemistry lessons often discussed principle of ester synthesis. Small modifications of "standard esterification" in the experimental procedure allow students to apply and refine their basic understanding. In the production of medicines, however, the important work just starts off after synthesis: Purification by recrystallisation and identification with thin-layer chromatography will follow immediately. In the second part of the course, the purity of the product is quantified. Salicylic acid impurity can be detected photometrically in the self-produced ASPIRIN®.
By prior arrangement, the course can be extended by the demonstration of further modern analysis methods: HPLC (within the one-day course), MS and/or H-NMR (with course extension).