Novel synthesis of 2-aminopentanedinitriles from 2-(bromomethyl)aziridines and their transformation into 2-imino-5-methoxypyrrolidines and 5-methoxypyrrolidin-2-ones

1-Arylmethyl-2-(bromomethyl)aziridines were transformed into 2-[N-(arylmethyl)amino]pentanedinitriles upon treatment with an excess of potassium cyanide in DMSO through an unprecedented and peculiar reaction mechanism, involving base-induced ring opening of intermediate 2-(cyanomethyl)aziridines into allylamines, followed by migration of the double bond out of the conjugation towards aldimines via enamine intermediates. The resulting aminopentanedinitriles served as substrates for the synthesis of novel 2-imino-5-methoxypyrrolidines upon treatment with sodium methoxide in methanol, which were either acetylated at the free imino group to afford the more stable N-acetylimino derivatives or hydrolyzed towards the corresponding synthetically relevant 5-methoxypyrrolidin-2-ones.