The synthesis of asymmetric ethylenediamine derivatives catalyzed by ion-exchange resins

Abstract

The ring-opening reaction of aziridine with alkylamines over a series of ion-exchange resins was investigated. Among these catalysts, D001-CC exhibited excellent catalytic performance. The catalysts were characterized by SEM and N₂ adsorption–desorption. The results indicated that the selectivity of N,N-diethylethylenediamine mainly depended on the acidity and S _BET of the resins. Strong Brönsted acid sites played an important role on the conversion of aziridine, and the distribution of acid sites on catalyst had a significant effect on the selectivity of N,N-diethylethylenediamine. The reaction parameters, such as reaction time, molar ratio, reaction temperature, and catalyst loading, were also optimized and N,N-diethylethylenediamine was obtained in an excellent yield of 97 %. Furthermore, D001-CC was efficiently recycled five times by simple treatment with large amounts of deionized water and mineral acid. Finally, a series of asymmetric ethylenediamine derivatives were successfully synthesized with this method. Therefore, a simple and versatile process for the synthesis of asymmetric ethylenediamine derivatives has been established over ion-exchange resins.