Identification, Synthesis, and Characterization of Process Related Impurities in the Synthesis of Boc‐L‐Lys(Boc)‐OSu

ABSTRACT Protected lysine esters (Boc‐L‐Lys(Boc)‐OSu) an intermediate of high repute in the peptide synthesis and diverse chemical synthetic applications, was the subject of synthetic process development studies, unveiling process‐related impurities. These impurities were synthesized, characterized, and identified by different analytical tools, with their retention times verified by HPLC co‐injection with commercial products. Detailed discussions ensued on the potential formation pathways and synthetic strategies of these process‐related impurities.