Aspirin Synthesis
Virtual Lab Bench
Observations
Reaction Scheme
Aspirin Synthesis Reaction:
Salicylic Acid + Acetic Anhydride → Aspirin + Acetic Acid
Catalyst: H₃PO₄ (phosphoric acid)
Conditions: Heat, followed by crystallization
About Aspirin Synthesis
Aspirin (acetylsalicylic acid) is one of the most widely used medications in the world. Its synthesis from salicylic acid is a classic example of pharmaceutical chemistry and demonstrates important organic synthesis principles.
Historical significance includes its discovery by Felix Hoffmann at Bayer in 1897, being the first synthetic drug to be mass-produced, deriving from willow bark extract (salicin), and being a Nobel Prize-worthy discovery for its mechanism of action. Synthesis considerations include using acetic anhydride (more reactive than acetic acid for acetylation), phosphoric acid catalyst (safer alternative to sulfuric acid), crystallization (purifies product by selective precipitation), and purity testing (FeCl₃ test confirms absence of salicylic acid impurities). The mechanism of action involves irreversibly inhibiting cyclooxygenase (COX) enzymes, reducing prostaglandin synthesis, and providing analgesic, antipyretic, and anti-inflammatory effects, plus low-dose cardioprotective effects through antiplatelet action. Industrial considerations include reaction yield optimization through excess reagents, temperature control to prevent decomposition, crystal size control for tablet formulation, and quality control testing for pharmaceutical standards.