This reaction is a simultaneous oxidation and nitration of aromatic compounds to form nitrophenols with nitric acid or higher nitrogen oxides in the presence of a mercury salt and is generally referred to as the Wolffenstein‐Böters reaction. In this reaction, usually more than one nitro group is introduced to the aromatic nucleus. The nitrobenzene and dinitrobenzene are formed as by‐products. This reaction is very useful for the preparation of nitrophenols.