The Bucherer reaction in organic chemistry is the reversible conversion of a naphthol to a naphthylamine in the presence of ammonia and sodium bisulfite.
[1][2][3][4][5] The reaction is widely used in the synthesis of dye precursors aminonaphthalenesulfonic acids.
The German chemist Hans Theodor Bucherer (1869–1949) discovered (independent from Lepetit) its reversibility and its potential especially in industrial chemistry.
[6] In the first step of the reaction mechanism a proton adds to a carbon atom with high electron density therefore by preference to C2 or C4 of naphthol (1).
A nucleophilic addition follows of the amine with formation of 4a and its tautomer 4b loses water to form the resonance stabilized cation 5a.