Organic Chemistry Lab Report: Synthesis of Aspirin

Abstract: This laboratory report documents the synthesis of acetylsalicylic acid (aspirin) through the esterification of salicylic acid with acetic anhydride. The experiment achieved a 78.4% yield with a melting point range of 135-137°C, indicating high purity. Spectroscopic analysis confirmed the successful synthesis of the target compound.

1. Introduction

Aspirin (acetylsalicylic acid) is one of the most widely used pharmaceutical compounds worldwide, serving as an analgesic, antipyretic, and anti-inflammatory agent. The synthesis of aspirin provides an excellent demonstration of esterification reactions and purification techniques fundamental to organic chemistry.

Reaction Equation:
C₇H₆O₃ + C₄H₆O₃ → C₉H₈O₄ + CH₃COOH
(Salicylic Acid + Acetic Anhydride → Aspirin + Acetic Acid)

2. Materials and Methods

Materials:
- Salicylic acid (2.0 g, 0.0145 mol)
- Acetic anhydride (5.0 mL, excess)
- Concentrated sulfuric acid (3 drops, catalyst)
- Distilled water, ice bath
- Filter paper, Buchner funnel

Procedure:
1. Salicylic acid (2.0 g) was placed in a 125 mL Erlenmeyer flask.
2. Acetic anhydride (5.0 mL) was added, followed by 3 drops of concentrated sulfuric acid as a catalyst.
3. The mixture was heated in a water bath at 50°C for 15 minutes with occasional swirling...

3. Results

Theoretical Yield: 2.61 g
Actual Yield: 2.05 g
Percent Yield: 78.4%
Melting Point: 135-137°C (Literature value: 138-140°C)