Mechanochemical Synthesis of Aspirin
Disciplines
Analytical Chemistry | Medicinal-Pharmaceutical Chemistry | Organic Chemistry
Abstract (300 words maximum)
Aspirin is one of the most popular pain reliever and anti-inflammatory drug used around the globe. In 1899, acetylsalicylic acid was patented as aspirin by Bayer pharmaceutical company. It is estimated that 40,000 metric tons aspirin being consumed each year in the world. Currently, aspirin is synthesized by thermochemical method at an elevated temperature of 85 °C where salicylic acid reacts with acetic anhydride in the presence of a catalyst, H3PO4. In this project, we report the first mechanochemical synthesis of aspirin. Mechanochemistry has emerged as a new field in which mechanical energy is exploited for chemical reaction. Mechanochemical synthesis is a greener approach as it is cost-effective and saves energy, however, it is less explored than other means of synthesis. Milling or grinding are the most common techniques used in mechanochemical synthesis. For mechanochemical synthesis of aspirin, 1.8 g of salicylic acid was mixed with 5 mL of acetic anhydride and five drops of 85% H3PO4 was added in the specialized reaction vessel. Twenty (20) stainless steel bearing balls of 6 mm was added to the reaction vessel. Rock tumbler which usually used for gems polishing was employed for this experiment. The reaction vessel containing reactants and catalyst was placed in the tumbler and run for an hour with the highest speed of 3. The IR spectrum of mechanochemically synthesized aspirin was compared with commercial aspirin and salicylic acid. Mechanochemical aspirin IR spectrum shows no characteristic -OH stretching peak as it appears in salicylic acid. In addition, two C=O stretching peaks are detected in 1748 and 1678 cm-1 for mechanochemical aspirin similar to the peaks detected in commercial aspirin. Liquid chromatography results shows that mechanochemical aspirin has nearly same retention time, peak area, and height similar to the commercial aspirin.
Academic department under which the project should be listed
CSM - Chemistry and Biochemistry
Primary Investigator (PI) Name
Mohammad A. Halim
Mechanochemical Synthesis of Aspirin
Aspirin is one of the most popular pain reliever and anti-inflammatory drug used around the globe. In 1899, acetylsalicylic acid was patented as aspirin by Bayer pharmaceutical company. It is estimated that 40,000 metric tons aspirin being consumed each year in the world. Currently, aspirin is synthesized by thermochemical method at an elevated temperature of 85 °C where salicylic acid reacts with acetic anhydride in the presence of a catalyst, H3PO4. In this project, we report the first mechanochemical synthesis of aspirin. Mechanochemistry has emerged as a new field in which mechanical energy is exploited for chemical reaction. Mechanochemical synthesis is a greener approach as it is cost-effective and saves energy, however, it is less explored than other means of synthesis. Milling or grinding are the most common techniques used in mechanochemical synthesis. For mechanochemical synthesis of aspirin, 1.8 g of salicylic acid was mixed with 5 mL of acetic anhydride and five drops of 85% H3PO4 was added in the specialized reaction vessel. Twenty (20) stainless steel bearing balls of 6 mm was added to the reaction vessel. Rock tumbler which usually used for gems polishing was employed for this experiment. The reaction vessel containing reactants and catalyst was placed in the tumbler and run for an hour with the highest speed of 3. The IR spectrum of mechanochemically synthesized aspirin was compared with commercial aspirin and salicylic acid. Mechanochemical aspirin IR spectrum shows no characteristic -OH stretching peak as it appears in salicylic acid. In addition, two C=O stretching peaks are detected in 1748 and 1678 cm-1 for mechanochemical aspirin similar to the peaks detected in commercial aspirin. Liquid chromatography results shows that mechanochemical aspirin has nearly same retention time, peak area, and height similar to the commercial aspirin.