Preparing of Aspirin

I.SynopsisThe synthesis of aspirin is known in organic chemistry as an esterification reaction.

In this experiment, preparation of aspirin were conducted and followed by recrystallisation to have it purified. Aspirin was prepared from salicylic acid and acetic anhydride. Concentrated sulphuric acid was added to speed up the reaction. It was then heated in water bath, removed, let it cooled and product was collected by suction filtration. As product collected was impure, purification was carried out by recrystallization. Then melting point of the product was determined in order to check the purity of aspirin.

Theoretical yield of aspirin expected from 2.4g of salicylic acid was calculated to be 3.15g. With the actual yield that was measured to be 0.99g, percentage yield could be calculated, which was 31.43% yield. Temperature range for the melting point was 138.6oC - 149.3oC. The product obtained was in powdery form aspirin.

II.Introduction1. Objective1.1This experiment was conducted so that students could familiarize with the preparation of some simple organic compound1.2Students

diagram showing the chemical synthesis of aspirin

Diagram showing the Kolbe-Schmitt reaction used in...

Acetyl salicylic acid chemical structure

know how to purify the compound by recrystallisation2. History of aspirinThe effects of aspirin-like substances were found since the ancient Greeks which was the use of the willow bark as a fever fighter. The leaves and bark of the willow tree contain a substance called salicin, a naturally occurring compound similar to acetylsalicylic acid, the chemical name for aspirin.

During the 1800s, various scientists extracted salicylic acid from willow bark and produced the compound synthetically. Then, in 1853, French chemist Charles F. Gerhardt synthesized a primitive form of aspirin, a derivative of salicylic acid. In 1897 Felix Hoffmann, a German chemist working at theBayer division of I.G. Farber, discovered a better method for synthesizing the drug.

The manufacture of aspirin has paralleled advancements in pharmaceutical manufacturing as a whole, with significant mechanization occurring during the...