PhNCO-enabled synthesis of secondary amides from N-(2-aminophenyl)benzamides

Abstract

We have successfully developed an efficient method for synthesizing secondary amides utilizing easily accessible N-(2-aminophenyl)benzamide and phenyl isocyanate. Notably, the leaving group can be easily recuperated as a carbonylated N-heterocycle, which holds notable relevance in pharmaceutical applications. The crux of this strategy involves a sequential nucleophilic/intramolecular addition process of phenyl isocyanate, followed by transamidation. Moreover, the protocol features atom-economy, practicality, a one-pot two-step reaction, and facile preparation of substrates.