Cl-PEG2-acid

This Cl-PEG2-acid linker is designed for modular assembly of PROTACs, providing a flexible polyethylene glycol spacer terminated with a carboxylic acid and a chloro-functional handle. Its ether-rich backbone enhances solubility and spatial reach between ligand modules, while the reactive termini enable robust conjugation strategies. The linker’s compatibility with common PROTAC synthesis workflows makes it useful for generating targeted protein degraders; detailed structural and reactivity considerations are provided below.

Structure: Cl-PEG2-acid consists of a short polyethylene glycol chain bearing ether linkages, a terminal chloro substituent, and a terminal carboxylic acid. It contains polar oxygen atoms that support hydrogen-bonding, and a carboxyl group capable of forming salts and activating derivatives for coupling.

Reactivity: The chloro handle supports nucleophilic substitution or related functionalization routes, enabling installation of PROTAC-reactive groups under conditions compatible with PEG linkers. The carboxylic acid can be converted to activated intermediates (for example, ester or amide-forming derivatives) using standard coupling chemistries. Typical approaches employ base and polar aprotic solvents, with reaction progress monitored by chromatographic methods to preserve linker integrity.