Selective chemical oxidation or reduction of chlorophenols with potassium nitrosodisulfonate

Abstract

The selective chemical oxidation or reduction of several substituted chlorophenols (2-chloro, 4-chloro, and 2,4-dichloro) was carried out with potassium nitrosodisulfonate. The reaction was followed by NMR and HPLC. This reaction was strongly dependent on the amount of potassium nitrosodisulfonate, the position of the chloro-substituent on the aromatic ring, the pH and temperature of reaction. At short reaction times, 4-chorophenol was selectively oxidized to 1,4-benzoquinone and 2-chlorophenol to 2-chloro-1,4-benzoquinone. In contrast, 2,4-dichlorophenol was selectively reduced to 4-chlorophenol.