Furan fused ring-substituted glutarimide compound

A compound of formula (II) or a pharmaceutically acceptable salt thereof,

• wherein
• PTM is selected from a drug or a derivative thereof that binds to an AR targeted protein;
• L1 is selected from —(CH2)n—, and each CH2 is optionally replaced by R1;
• R1 is selected from C3-7 cycloalkyl, 6-membered heterocycloalkyl, —NRa—, —CRbRc—, —CH2CH2O—, and —NHC(═O)—;
• Ra is selected from H and C1-3 alkyl;
• Rb and Rc are each independently selected from H, D, and F;
• E1 is selected from a single bond and O;
• ring A is absent;
• or ring A is selected from phenyl and 5-membered heteroaryl;
• n is selected from 1, 2, 3, 4, 5, and 6;
• the 6-membered heterocycloalkyl and 5-membered heteroaryl contain 1, 2, or 3 heteroatoms or heteroatom groups independently selected from —NH—, —O—, —S—, and N, respectively;
• provided that the compound is not selected from: