PROTAC ATR degrader-2 (Compound 8i) is a PROTAC degrader for ATR, through of. PROTAC ATR degrader-2 degrades ATR in acute myeloid leukemia (AML) cells MV-4-11 and MOLM-13, with DC50 of 22.9 and 34.5 nM. APROTAC ATR degrader-2 induces apoptosis, inhibits proliferations of AML cells. PROTAC ATR degrader-2 exhibits good pharmacokinetics charachers and antitumor efficacy against AML in mouse model. (Pink: ATR ligand ; Blue:E3 ligase ligand Lenalidomide (HY-A0003) ; Black: linker)