Thalidomide-5-(PEG2-acid) is a PROTAC building block that contains an E3 ligase ligand substituted with carboxylic acid. The terminal carboxylic acid can react with primary amine groups in the presence of activators (e.g. EDC, or HATU) to form a stable amide bond. Reagent grade, for research purpose. Please contact us for GMP-grade inquiries.