6-(2,5-Dioxo-2,5-dihydro-1H-pyrrol-1-yl)hexanehydrazide 2,2,2-trifluoroacetate is a heterobifunctional linker used in bioconjugation and the synthesis of biologically active compounds. The maleimide group enables selective conjugation to thiol (-SH) residues on proteins or peptides, while the hydrazide functionality allows formation of stable bonds with aldehyde or ketone groups, such as on oxidized glycans. It serves as a key intermediate in pharmaceutical development and drug discovery for creating hydrazide derivatives, antibody-drug conjugates, and targeted therapeutics. Applied in organic and biochemical research to explore molecular interactions, reaction mechanisms, and novel entities with enhanced efficacy, specificity, and potential for disease treatment or diagnostics.