H-Lys(Z)-OtBu.HCl, a lysine derivative, serves as a synthetic organic compound extensively utilized in scientific research. H-Lys(Z)-OtBu.HCl represents the hydrochloride salt of the tert-butyl ester of 6-aminohexanoic acid. The tert-butyl ester of 6-aminohexanoic acid acts as a carboxylic acid, serving as a valuable tool in peptide synthesis for the production of peptide amides, peptide esters, and other peptide derivatives. Furthermore, the hydrochloride salt of the tert-butyl ester of 6-aminohexanoic acid assumes a crucial role as a building block in organic synthesis, enabling the creation of diverse organic compounds, such as tri-tert-butyl (9S,13S)-3,11-dioxo-1-phenyl-2-oxa-4,10,12-triazapentadecane-9,13,15-tricarboxylate.