Rapid and efficient synthesis of five- to eight-membered cyclic aminals under ultrasound irradiation

Abstract

A simple, efficient, and green procedure has been developed for the synthesis of cyclic aminals from alkylenediamines and aqueous formaldehyde under ultrasound irradiation. Applying this methodology a series of five-to eight-membered 1,3-dibenzyl substituted aminals were synthesized in excellent yields after short reaction times. Results were compared to thermal conventional method. All novel compounds were identified and characterized by 1H and 13C NMR spectra.