Hepatitis C virus (HCV) NS5B RNA polymerase is crucial for replicating the HCV RNA genome and is an attractive target for developing anti-HCV drugs. A novel series of 2, 3- diaryl-1, 3-thiazolidin-4-one derivatives were evaluated for their ability to inhibit HCV NS5B. Of this series, compounds 4c, 5b, 5c and 6 emerged as more potent, displaying over 95% inhibition of NS5B RNA polymerase activity in vitro. The two most active compounds 4c ...