A facile electrochemical method for synthesis of new amino-substituted 1,4-benzoquinone derivatives

Abstract

Electroorganic synthesis has become recognized as a powerful tool to develop environmentally compatible processes.1 It is characterized by high selectivity, readily available starting materials, good atom economy, low energy consumption and temperature, low costs for reagents, and material failure. In addition, electrons are considered to be clean reagents,2 and electrodes may be regarded as heterogeneous catalysts that are easily separated from the products. So, it can be concluded that electrosynthesis is a green tool for organic synthesis. During an organic electrochemical reaction, organic molecules are activated by the addition or removal of electrons at the surface of an electrode through a heterogeneous process. A large variety of C-C, C-N, C-O and C-S bond forming reactions and functional group interconversions can be achieved by electron transfer.3 Hydroquinone is an important organic compound that is widely used in many fields such as pharmaceutical, antioxidant, dye, photography and cosmetic industries.4 Electrochemical oxidation of hydroquinones in the presence of 2-amino-4-methyl pyridin as a nucleophile have been studied in aqueous phosphate buffer solution using cyclic voltammetry and control potential coulometry. The cyclic voltammetric results showed that an electro oxidative/ Michael type sequential reaction occurs between the 2-amino-4-methyl pyridin and electrochemically generated p-bezoquinones leading to the desire products (Scheme 1).