Benzylamine and Dibenzylamine Revisited. Syntheses of N-Substituted Aryloxypropanolamines Exemplifying a General Route to Secondary Aliphatic Amines

Abstract

During the course of our syntheses of N-substituted aryloxypropanolamines, we have examined the opening of epoxides by primary amines under a variety of experimental conditions. Although secondary amines resulting from monoalkylation represented the desired products, dialkylation was typically problematic when the primary amines were not substituted in the alpha-position. For example, alkylation of β-alanine with epoxide 1 produced the tertiary amine 2 in 35% yield even when a ten—fold excess of β-alanine was employed.¹