Synthesis of Aspirin Laboratory Report

Organic synthesis involves the construction of desired organic compounds from commercially available materials. The primary goal is to design efficient synthetic routes to molecules. In this experiment, the focus is on the synthesis of acetylsalicylic acid, commonly known as aspirin. Aspirin is a widely used medication for reducing fever and alleviating pain. It is an acetyl derivative of salicylic acid, presenting as a white, crystalline substance with a melting point of 135°C.

The synthesis of aspirin involves the reaction between salicylic acid and acetyl anhydride, leading to the conversion of salicylic acid's hydroxyl group into an acetyl group (R—OH → R—OCOCH3).

The presence of an inorganic acid, such as phosphoric acid, serves as a catalyst for this reaction.

II. Objectives

1. Introduce the concept of organic synthesis.
2. Synthesize acetylsalicylic acid from salicylic acid through nucleophilic acyl substitution.
3. Differentiate acetylsalicylic acid from salicylic acid through simple chemical tests.

III. Materials and Methods

Materials:

1. Salicylic acid
2. Acetic anhydride
3. Phosphoric acid (catalyst)
4. Apparatus for reflux
5. Ice bath
6. Filtration setup
7. Ethanol
8. Distilled water

Methods:

1. Weighed and mixed salicylic acid, acetic anhydride, and phosphoric acid.
   Get quality help now

   

   WriterBelle

   Verified writer

   Proficient in: Chemistry

   4.7 (657)

   “ Really polite, and a great writer! Task done as described and better, responded to all my questions promptly too! ”

   

   +84 relevant experts are online

   Hire writer

2. Carried out the reaction under reflux conditions.
3. Cooled the reaction mixture in an ice bath.
4. Filtered the obtained precipitate.
5. Washed the solid with ethanol and dried it.
6. Performed chemical tests to differentiate salicylic acid from aspirin.

IV. Data

Yield and Characteristics of Aspirin

The synthesis of acetylsalicylic acid commenced with the combination of salicylic acid, acetic anhydride, and phosphoric acid as a catalyst.

Under reflux conditions, a white, milky mixture was observed. The reaction mechanism involves the nucleophilic acyl substitution, where the hydroxyl group of salicylic acid is replaced by the acetyl group from acetic anhydride.

The obtained product, acetylsalicylic acid, appeared as a white, crystalline substance with a melting point of 135°C. The yield was calculated to be B%, indicating the efficiency of the synthesis process.

The differentiation of acetylsalicylic acid from salicylic acid was achieved through various chemical tests. These tests provided conclusive evidence of the successful conversion of salicylic acid to aspirin.

In conclusion, the synthesis of aspirin involved the reaction between salicylic acid and acetic anhydride in the presence of phosphoric acid as a catalyst. The obtained product exhibited the characteristic features of acetylsalicylic acid. The chemical tests conducted confirmed the successful synthesis, highlighting the importance of organic synthesis in obtaining specific pharmaceutical compounds.

This laboratory experiment not only provided hands-on experience in organic synthesis but also emphasized the significance of precise measurements and careful experimental techniques. The obtained results contribute to a better understanding of the synthesis of aspirin and its applications in the pharmaceutical industry.