Synthesis of N-Aminated Salts of Aliphatic tert-Amines, (Trialkyl)amidines, and (Pentaalkyl)guanidines by Electrophilic Amination in an Ethereal Solvent

Abstract

The electrophilic amination of nitrogen-based nucleophiles, including strong organic bases, was conducted in an Et₂O solvent using O-(mesitylenesulfonyl)hydroxylamine. Aliphatic tert-amines and N,N,N′-(trialkyl)amidines rapidly formed precipitates of the corresponding aminated salts in high yields. The amination of the highly basic and sterically hindered N,N,N′,N′,N″-(pentaalkyl)guanidines was achieved under modified conditions, although the yields were moderate because of a competing side reaction caused by the acid–base equilibrium.