Electrochemical Intramolecular Dehydrogenative Coupling of <i>N</i>‐Benzyl(thio)amides: A Direct and Facile Synthesis of 4<i>H</i>‐1,3‐Benzoxazines and 4<i>H</i>‐1,3‐Benzothiazines

Abstract

The electrochemical dehydrogenative cyclization of N ‐benzylamides was investigated with a Pt plate anode and graphite rod cathode in an undivided cell at room temperature. The oxidative degradation of the products was suppressed successfully and 4 H ‐1,3‐benzoxazines were obtained regardless of the substituents at the benzylic position. This method also allowed for the preparation of 4 H ‐1,3‐benzothiazines.