Mcl-1 inhibitor 20 (compound 47) is a Mcl-1 inhibitor with anti-leukemic effects. Mcl-1 inhibitor 20 can bind to the BH3 binding groove of Mcl-1 (Ki=24 nM), occupy the P1 pocket in Mcl-1 , and form interactions with Lys234 and Val249. Mcl-1 inhibitor 20 has good microsomal stability, pharmacokinetic characteristics and low cardiotoxicity.