The Research On The Synthetic Methods Of Ethylenediamine Derivatives

Ethylenediamine derivatives are important intermediates in varieties of fieldssuch as fabric softener, surfactant, preservatives and germicide. Ethylenediaminederivatives have been synthesized by many methods. However, all of these methodssuffer from the drawbacks such as longer reaction steps, the lower yields of thedesired products, harsh reaction conditions and unfriendly to the environment, leavingscope for further development of a new and handy method which is suitable forindustrialization for the synthesis of ethylenediamine derivatives.In this paper, we studied the method of synthesizing ethylenediamine derivativesby aziridine with alkylamines over different acid catalysts and focused on establishinga new, simple and environmental friendly process which is suitable forindustrialization for the synthesis of ethylenediamine derivatives. Through the studyand filter of different acid catalysts, we ascertain D001-CC macroporous strong acidion-exchange resin as catalyst to catalyze the nucleophilic ring-opening reaction ofaziridine with diethylamine. The catalysts were characterized by N2adsorption-desorption and SEM. The results indicated that the catalytic activity of the catalystsincreased with the decrease of acid sites per unit specific surface area for the strongacid ion-exchange resins. The reaction parameters were also optimized (i.e. reactiontemperature of65℃, dimethylamine/ethyleneimine molar ratio of4:1, catalyst loadingis equal to15wt.%of the feedstocks, and the reaction time of5h), and under theconditions determined above, N,N-diethylethylenediamine was obtained in anexcellent yield of97.3%. Furthermore, D001-CC resin was efficiently recycled sevencycles by simple treatment with large amount of deionized water and mineral acid.Finally, a series of ethylenediamine derivatives such as N-methyl-ethylenediamine,N-ethyl-ethylenediamine, N-n-propyl-ethylenediamine, N-isopropyl-ethylenediamine,N-n-butyl-ethyl-enediamine, N-benzyl-ethylenediamine, and N,N-dimethyl-ethylene-diamine were successfully synthesized with the nucleophilic ring-opening reaction ofaziridine with alkylamines and the universality of the catalyst was demonstrated.Moreover, a conclusion can be made that steric hindrance of alkylamines plays animportant role on the nucleophilic ring-opening reaction of aziridine.