Diethylene glycol dimethanesulfonate

This diethylene glycol dimethanesulfonate is a bifunctional mesylate linker designed for constructing PROTACs and related targeted protein degradation conjugates via reliable electrophile–nucleophile coupling. Its two activated sulfonate termini enable stepwise assembly of ternary or modular degraders, supporting efficient linkage formation under standard organic synthesis conditions. The subsequent points describe its structural features and practical reactivity considerations for experimental workflows.

Structure: The linker consists of a flexible diethylene glycol core bearing two methanesulfonate (mesylate) leaving groups. It contains ether linkages within the backbone and sulfonate ester functionalities at both termini, providing polar character and good leaving-group ability for nucleophilic substitution.

Reactivity: The mesylate groups undergo nucleophilic substitution with amines, thiols, or other nucleophiles to form C–N or C–S (and related) linkages commonly used in PROTAC synthesis. Typical conditions employ anhydrous polar aprotic solvents and base to generate the nucleophile, while temperature and stoichiometry are tuned to favor substitution over side reactions. No special catalysts are generally required beyond standard coupling base/conditions used for sulfonate ester chemistry.