Physical properties of aromatic nitro compounds

• Reduction of aromatic nitro compounds with hydrogen gas over a catalyst gives anilines. A variation is formation of a dimethylaminoarene with palladium on carbon and formaldehyde:
• The Leimgruber-Batcho, Bartoli and Baeyer-Emmerling indole syntheses begin with aromatic nitro compounds.
• Indigo can be synthesized in a condensation reaction from ortho-nitrobenzaldehyde and acetone in strongly basic conditions in a reaction known as the Baeyer-Drewson indigo synthesis
• The presence of nitro groups facilitates nucleophilic aromatic substitution because they are very electron-withdrawing.