The Zincke nitration is an organic reaction in which a bromine substituent of a phenol or cresol is replaced by a nitro group by treatment with nitrous acid or sodium nitrite. The reaction is a manifestation of nucleophilic aromatic substitution. The reaction is named after Theodor Zincke.
Two examples:
and:
The Zincke nitration should not be confused with the Zincke-Suhl reaction or the Zincke reaction.