N3-PEG12-Hydrazide

N3-PEG12-Hydrazide is a PEG-based hydrazide linker designed to connect PROTAC warheads and enable efficient formation of degraders with tunable solubility and linker flexibility. Its ether-rich PEG scaffold supports favorable aqueous handling and can help accommodate diverse target-binding geometries while maintaining productive ternary-complex formation. The hydrazide functionality provides a chemically addressable site for controlled conjugation strategies. Detailed structural and reactivity considerations are provided below.

Structure: This linker contains a polyethylene glycol chain terminated by a hydrazide group, featuring ether linkages along the PEG backbone and a hydrazide functional motif capable of hydrogen bonding. The flexible, polar PEG segment typically enhances aqueous solubility and conformational adaptability in bioconjugation contexts.

Reactivity: The hydrazide group is commonly used for amide bond formation or for hydrazone-related conjugation workflows, depending on the complementary partner chemistry. For PROTAC assembly, coupling is typically performed under mild conditions using standard amide-forming reagents (e.g., carbodiimide-based systems) in appropriate polar solvents, with pH control to favor nucleophilic activation. Reaction progress is usually monitored by chromatographic or spectrometric methods to ensure clean linker incorporation.