Thalidomide -PIP-(R)C-pyrrolidine-boc is a conjugate of E3 ligase ligand and linker , consisting of Thalidomide and the corresponding Linker. Thalidomide -PIP-(R)C-pyrrolidine-boc can serve as a Cereblon ligand to recruit CRBN protein and serve as a key intermediate for the synthesis of complete PROTAC molecules.