Nitro compounds are organic compounds that contain one or more nitro functional groups (-₂). They are often highly explosive; various impurities or improper handling can easily trigger a violent exothermic decomposition.

Aromatic nitro compounds are typically synthesized by the action of a mixture of nitric and sulfuric acids on a suitable organic molecule. Some examples of such compounds are trinitrophenol (picric acid), trinitrotoluene (TNT), and trinitroresorcinol (styphnic acid).

Preparation

In organic synthesis various methods exists to prepare nitro compounds.

Aliphatic nitro compounds

• Nitromethane adds to aldehydes in 1,2-addition in the nitroaldol reaction
• Nitromethane adds to alpha-Beta unsaturated carbonyl compounds as a 1,4-addition in the Michael reaction as a Michael donor
• Nitroethylene is a Michael acceptor in a Michael reaction with enolate compounds
• In nucleophilic aliphatic substitution sodium nitrite (NaNO₂) replaces an alkyl halide

Aromatic nitro compounds

• In electrophilic substitution nitric acid reacts with aromatic compounds in nitration

Reactions

Nitro compounds participate in several organic reactions.

Aliphatic nitro compounds

• Aliphatic nitro compounds are reduced to amines with hydrochloric acid and an iron catalyst
• Hydrolysis of nitro compounds yield aldehydes or ketones in the Nef reaction

Aromatic nitro compounds

• Reduction of aromatic nitro compounds with hydrogen gas over a platinum catalyst gives anilines.
• The presence of nitro groups facilitates nucleophilic aromatic substitution.

See also

• Functional group

Nitrogen compounds | Nitro compounds | functional groups

Organische Nitroverbindung | Nitrosavienojumi | Nitrozwiązki | ニトロ化合物 | 硝基化合物 | Nitrosavienojumi