Acetaminophenol Synthesis Lab Report

Aims
The aim of this experiment was to synthesis acetaminophen from 4-aminophenol and acetic anhydride. The crude synthesised acetaminophen was then compared to USP grade acetaminophen by some tests. Both of these acetaminophen undergoes infrared spectroscopy, melting point, ultraviolet spectrum, thin layer chromatography and residual free 4-aminophenol testes. Physical properties of ten tablets of 500mg panadol were measured by using vernier callipers and analytical balance.
Introduction
Acetaminophen also known as paracetamol1. Its belong to pain killer and fever reducer category in drug classification2. It exists in several form, such as tablet, suspension and capsule. Acetaminophen acts as a pain killer by reducing the brain from producing

Acetaminophen can be synthesised from 4-aminophenol and acetic anhydride. Acetaminophen is an amide group. The 4-aminophenol is an amine group, it reacted with acid anhydride to form acetaminophen. Figure 2: Formation of acetaminophen from 4-aminophenol and acetic anhydride5.
Some tests were carried out on the synthesised acetaminophen and USP grade acetaminophen. Infrared spectroscopy, melting point, ultraviolet spectroscopy, thin layer chromatography and absorbance of residual free 4-aminophenol were observed.
Infrared spectroscopy allowed the chemist to detect the types of bond and functional group present in a molecule6. The infrared light will interact with the molecule, the atoms in the molecule will vibrate. The energy is absorbed by the bond between the atoms. Each bond has different vibration energy as the environment of the bonds affect the amount of intensity absorbed and vary the frequency5. The infrared spectrum wavelength range from 4000cm-1 to 400cm-1. Figure 2: Infrared spectrum of vanillin7.
The transmittance is the amount of light passes through the sample6. The lower the percentage of transmittance, higher amount of light absorbed by the

This gave an idea about the purity of the particular substance. A narrow range of melting point is favourable, as this indicated the compound is pure8. If a compound has lower temperature compared to its pure compound, this indicated this compound contain impurity8. An impurity compound will also has a wide range of melting point7.
In ultraviolet spectrum, the light energy is absorbed to promote the electrons from highest occupied molecular orbital (HOMO) to the lowest unoccupied molecular orbital (LUMO) 9. This makes the compounds coloured as it gave the compound complimentary coloured to the colour of light