Rearrangements during nitrosodecarboxylation of isomeric dibromohydroxybenzoic acids

The reaction of 3,5-dibromo-4-hydroxybenzoic acid, its sodium salt, and also sodium 3,5-dibromo-2-hydroxybenzoate with NaNO₂ in a glacial acetic acid at room temperature led to the formation of a mixture of dibromonitrophenol resulting from nitrosodecarboxylation accompanied by a rearrangement processes and followed by oxidation of the arising nitrosophenols.