N3-PEG3-CH2CH2-Boc is a cleavable 3 unit polyethylene glycol (PEG) ADC linker utilized in the synthesis of antibody-drug conjugates (ADCs)[1]. This compound also functions as a PEG- and alkyl/ether-based PROteolysis TArgeting Chimera (PROTAC) linker, suitable for the construction of PROTAC molecules[2].

ADCs are comprised of an antibody to which is attached an ADC cytotoxin through an ADC linker[1]. PROTACs contain two different ligands connected by a linker; one is a ligand for an E3 ubiquitin ligase and the other is for the target protein. PROTACs exploit the intracellular ubiquitin-proteasome system to selectively degrade target proteins[2].