Electrochemical Cyclization–Desulfurization Approach for the Synthesis of 1,3-Benzoxazines Using Cascade C–O and C–N Bond Formation

A cost-effective, eco-friendly, and highly efficient one-pot electrochemical process has been described for the synthesis of 4H-1,3-benzoxazine and 4,5-dihydro-1,3-benzoxazepine derivatives by employing 2-aminobenzyl alcohols, 2-(2-aminophenyl)ethan-1-ol, isothiocyanate derivatives, and TBAPF6 as an electrolyte. The developed method is accomplished at 25 °C with a constant current of 20 mA. Utilizing a graphite anode and a platinum cathode in a dimethyl sulfoxide solvent, the devised metal-free electrochemical approach minimizes the production of waste and eliminates the need for external oxidizing agents. Furthermore, the synthesis of these valuable molecules by employing an electrochemical approach significantly enhances the ongoing trends in synthetic organic chemistry.