m-PEG3-Propanoyl chloride

m-PEG3-Propanoyl chloride is a PEG-based acylating linker designed for constructing PROTAC conjugates through reliable amide-bond formation. Its ether-rich, flexible polyethylene glycol segment can enhance solubility and provide a tunable spacer between targeting ligands and reactive handles, supporting efficient synthesis of degraders. The acid chloride functionality enables straightforward coupling to appropriate nucleophiles under standard acylation protocols.

Structure: The linker contains a PEG chain terminating in a propanoyl chloride group, featuring ether linkages along the flexible poly(ethylene glycol) backbone. A reactive acyl chloride moiety provides a polarized carbonyl center suitable for nucleophilic acyl substitution, enabling formation of stable amide linkages.

Reactivity: Use this acyl chloride for acylation reactions with amines or other suitable nucleophiles to generate amide linkages commonly employed in PROTAC linker assembly. Typical conditions involve anhydrous, inert atmosphere handling, low-water solvents, and a base to scavenge generated acid. The reaction proceeds via nucleophilic acyl substitution at the acid chloride, often using amine partners and standard acylation catalysts or activators only when required by substrate reactivity.