4-Nitroaniline

Overview
4-Nitroaniline, p-nitroaniline or 1-amino-4-nitrobenzene is an organic compound with the formula C6H6N2O2. It is an organic chemical compound, consisting of a phenyl group attached to an amino group which is para to a nitro group. The chemical structure of p-nitroaniline is shown at the right. This chemical is commonly used as an intermediate in the synthesis of dyes, antioxidants, pharmaceuticals and gasoline, in gum inhibitors, poultry medicines, and as a corrosion inhibitor.

Synthesis
Below is an example synthesis of p-nitroaniline from aniline. The key step in this reaction sequence is an electrophilic aromatic substitution to install the nitro group para to the amino group. After this reaction, a separation must be performed to remove 2-nitroaniline, which is also formed in a small amount during the reaction.



Applications
4-Nitroaniline is a starting material for the synthesis of Para Red, the first azo dye:



Toxicity
The compound is toxic by way of inhalation, ingestion, and absorption, and should be handled with care. Its LD50 in rats is 750 mg/kg when administered orally. p-Nitroaniline is particularly harmful to all aquatic organisms, and can cause long-term damage to the environment if released as a pollutant.