Mechanochemical Bromination of Naphthalene Catalyzed by Zeolites: From Small Scale to Continuous Synthesis

Abstract

Abstract Catalyzed reactions of organic substrates that operate continuously by extrusion techniques are rare. In this study, we developed a mechanochemical bromination of unactivated naphthalene ( 1 ) with 1,3‐dibromo‐5,5‐dimethylhydantoin ( DBDMH ), catalyzed by zeolites in a ball mill. The use of DBDMH enabled the atom economy of the reaction to be superior compared to the other brominating agents evaluated. Among the zeolites tested, a FAU‐type zeolite demonstrated high catalytic activity and recyclability. The success of the bromination route on a small scale enabled the development of a continuous catalyzed bromination of 1 by twin‐screw extrusion.