Acid-Catalyzed Reaction of (4,4-Diethoxybutyl)ureas with Phenols as a Novel Approach to the Synthesis of <font>α</font>-Arylpyrrolidines

Abstract

1-(4,4-Diethoxybutyl)-3-alkylureas undergo intramolecular cyclization in the presence of trifluoroacetic acid and various phenols, leading to the new N-alkyl-2-arylpyrrolidine-1-carboxamides with moderate to excellent yields. It was found that these compounds undergo spontaneous solid-phase epimerization at room temperature. Advantages of the proposed approach are mild reaction conditions and no need for expensive reagents or catalysts.