Benzyl-PEG3-MS

Benzyl-PEG3-MS is a polyethylene glycol–based linker designed for constructing PROTACs that require controlled spacing, aqueous compatibility, and efficient conjugation between targeting ligands. Its PEG segment helps tune linker flexibility and solvation, which can improve productive ternary complex formation and overall degradation performance. The benzyl group and the activated “MS” handle enable practical synthetic attachment strategies, and the details below describe its structure and the typical reactivity used in PROTAC assembly.

Structure: The linker contains an ether-rich PEG backbone providing conformational flexibility and hydrophilicity, coupled to a benzyl substituent. The functional “MS” portion is an activated moiety suitable for covalent coupling, while the overall scaffold is characterized by stable C–O and C–C connectivity typical of PEG-linker chemistries.

Reactivity: This linker is commonly employed in PROTAC synthesis via nucleophilic substitution or coupling reactions at the activated “MS” functional site, forming a stable covalent linkage to the partner ligand. Reactions are typically performed under inert or controlled atmospheres as needed for activated intermediates, using polar aprotic or compatible aqueous-organic solvent systems. Base and temperature are selected to balance activation stability with efficient coupling, following established PEG-linker PROTAC conjugation protocols.