(S)-Thalidomide-piperazine-pyrimidine-piperazine-C2-OH is a conjugate of E3 ligase ligand and linker , consisting of Thalidomide and the corresponding Linker. (S)-Thalidomide-piperazine-pyrimidine-piperazine-C2-OH can serve as a Cereblon ligand to recruit CRBN proteins and serve as a key intermediate for the synthesis of complete PROTAC molecules.