A novel series of benzofuran derived EZH2 inhibitors were discovered through a scaffold hopping approach based on the clinical compound of EPZ-6438. Further rational structure-activity relationship exploration and optimization led to the discovery of more potent EZH2 inhibitors with oral bioavailability in mice and rats. A lead compound EBI-2511 (compound 34) demonstrated excellent in vivo efficacy in Pfeiffer tumor Xenograft models in mouse and is under preclinical development for the treatment of cancers associated with EZH2 mutations.