Thalidomide-Pip-C-Pip-O-C-boc is a conjugate of E3 ligase ligand and linker, consisting of Thalidomide (HY-14658) and the corresponding Linker. Thalidomide-Pip-C-Pip-O-C-boc can serve as a Cereblon ligand to recruit CRBN protein and serve as a key intermediate for the synthesis of complete PROTAC molecules.