N,N'-DME-N,N'-Bis-PEG2-acid

N,N'-DME-N,N'-Bis-PEG2-acid is a PEG-based PROTAC linker designed to connect an E3 ligase ligand and a target-binding ligand while promoting solubility and conformational flexibility. Its ether-rich PEG segments can help reduce aggregation and improve handling of conjugates in aqueous media, supporting efficient formation of ternary complexes in targeted protein degradation workflows. The following sections describe the linker’s structure and the practical reactivity considerations relevant to PROTAC assembly.

Structure: The linker contains a bis-PEG architecture with ether linkages that confer hydrophilicity and chain flexibility. A central N,N′-dimethyl ether motif and amide-bearing “acid” functionality provide defined connection points for conjugation, enabling formation of stable covalent bonds to partner ligands.

Reactivity: The “acid” handle is suitable for standard amide coupling strategies commonly used in PROTAC synthesis, typically via activation of the carboxylic acid followed by reaction with an amine-bearing ligand. Conditions are generally optimized to minimize side reactions and preserve sensitive functional groups. Solvent systems such as polar aprotic media and appropriate coupling reagents (e.g., carbodiimide-based activators with additives) are frequently employed to promote efficient bond formation.