Thalidomide-NH-C4-NH2 TFA (compound 29c) is an E3 ligase ligand-linker conjugate, and incorporates the Thalidomide based cereblon ligand and a linker. Thalidomide-NH-C4-NH2 TFA is used in PROTAC BRD2/BRD4 degrader-1 (HY-130612). PROTAC BRD2/BRD4 degrader-1 is a potent and selective BET protein BRD4 and BRD2 degrader[1].