Béchamp reduction

The Béchamp reduction (or Béchamp process) is a chemical reaction that converts aromatic nitro compounds to their corresponding anilines using iron as the reductant:[1] This reaction was once a major route to aniline, but catalytic hydrogenation is the preferred method.

[2] The reaction was first used by Antoine Béchamp to reduce nitronaphthalene and nitrobenzene to naphthylamine and aniline, respectively.

Tertiary aliphatic nitro compounds, however, are converted in good yield to the amine using the Béchamp reduction.

The Laux process is based on the finding that the oxide coproduct is strongly affected by various additives, such as ferrous chloride, aluminium chloride, and even simply sulfuric acid, which are added before heating the iron-nitrobenzene mixture.

The innovations from Laux have shifted the emphasis of the Béchamp reduction for the manufacture of anilines to the production of valuable iron oxide pigments.