Aspirin: A Comparative Analysis of Different Synthetic Routes of Active Pharmaceutical Ingredients

Aspirin, chemically known as acetylsalicylic acid, is a widely used non-steroidal anti-inflammatory drug (NSAID) known for its analgesic, antipyretic, anti-inflammatory, and antiplatelet effects. It is commonly synthesized by acetylating salicylic acid, and over time, many different synthetic methods have been developed. This review presents a detailed comparison of ten synthetic routes for preparing aspirin, including classical acetylation, acetyl chloride-based acetylation, microwave-assisted synthesis, transesterification, enzymatic acetylation, and other alternative methods. Each method was analyzed based on the type of acetylating agent, reaction conditions, yield, purity, advantages, and limitations. Among these, the microwave-assisted method showed the highest yield and fastest reaction time, while enzymatic and electrochemical methods were found to be more environmentally friendly. The study highlights how the choice of synthetic route affects not only the efficiency of aspirin production but also its scalability, cost, and environmental impact. This comparative analysis will help researchers and industries choose the most suitable method for aspirin synthesis based on their specific needs and resources.