N-benzylidene benzylamine and its derivatives are common functional molecules in organic intermediates, fine chemicals and pharmaceuticals, and have been widely used in medicinal chemistry, materials science and natural product synthesis, such as the synthesis of anticancer and anti-inflammatory agents. Electrochemistry has become a powerful tool in organic synthesis to avoid the use of expensive and toxic oxidants or reductants to reduce the production of harmful and toxic by-products. Therefore, In this paper, we report a method for the synthesis of N-benzylidene benzylamine from dibenzylamine under electrochemical conditions, and its derivatization is studied by a one-pot tandem reaction. N-benzylidene benzylamines were electrolyzed at room temperature with graphite rod (Φ=6 mm) and Pt plate (10 mm×10 mm×0.2 mm) as electrode, ethyl acetate as solvent, and tetrabutylammonium perchlorate (n-Bu₄NClO₄) as electrolyte. Sixteen N-benzylidene benzylamines compounds were successfully prepared by this method, and the GC yield was as high as 96%. The “one-pot method” tandem reaction is a simple, fast and environment-friendly synthesis and preparation method, which uses simple, easy-to-obtain and inexpensive raw materials to prepare complex structures and high-value organic compounds through this “one-pot method” series reaction, without the separation and purification of intermediate products to obtain the required products, especially suitable for reaction systems with unstable intermediate products, which has the advantages of simple operation, simple post-treatment, less product loss, and less waste. In order to highlight the application value of N-benzylidene benzylamines, the derivatization reaction of N-benzylidene benzylamine by one-pot tandem method was further explored. And 15 derivatization products were prepared, isolated yield up to 86%. Finally, through control experiments, salt bridge experiments, cyclic voltammetry experiments and related literature reports, we speculated the possible reaction mechanism of this reaction. The reaction has the characteristics of mild conditions, wide range of substrates, good tolerance of functional groups, without redox agents and insensitivity to air and moisture. This study provides an efficient and economical synthesis strategy for the preparation of N-benzylidene benzylamines derivatives.

Key words: dibenzylamine, N-benzylidene benzylamine, one-pot tandem reaction, organic electrosynthesis