HCV NS5B polymerase inhibitors 3: Synthesis and in vitro activity of 3-(1,1-dioxo-2H-[1,2,4]benzothiadiazin-3-yl)-4-hydroxy-2H-quinolizin-2-one derivatives

Controllable synthesis of 3-iodo-2H-quinolizin-2-ones and 1,3-diiodo-2H-quinolizin-2-onesviaelectrophilic cyclization of azacyclic ynones

An efficient approach was developed to divergently synthesize 3-ipdo-2H-quinolizin-2-ones and 1,3-diiodo-2H-quinolizin-2-ones from azacyclic ynones with high regioselectivity under metal-free, room temperature conditions in air.

Recent advances in drug discovery of benzothiadiazine and related analogs as HCV NS5B polymerase inhibitors

Hepatitis C virus (HCV) is a major health burden, with an estimated 170 million chronically infected individuals worldwide, and a leading cause of liver transplantation. Patients are at increased risk of developing liver cirrhosis, hepatocellular carcinoma and even liver failure. In the past two decades, several approaches have been adopted to inhibit non-structural viral proteins. The RNA-dependent RNA polymerase (NS5B) of HCV is one of the attractive validated targets for development of new drugs to block HCV infection. In this review, we report the recent progress made towards identifying and developing benzothiadiazines as HCV NS5B polymerase inhibitors. The substituted benzothiadiazine class was identified by HTS in 2002 as an NS5B inhibitor. Further optimization and modification of the core has improved the potency and pharmacokinetic properties of substituted benzothiadiazines. Research on palm site-binding benzothiadiazine analogs and related derivatives and analogs is discussed in this article.

Non-nucleoside inhibitors of hepatitis C virus polymerase: current progress and future challenges

The current standard of care for hepatitis C virus (HCV) infection is a combination of PEGylated interferon and ribavirin, which offer limited efficacy and significant side effects. Novel HCV-specific inhibitors, including those directed at the viral polymerase, have become the focus of HCV drug-discovery efforts in the past decade. In addition to the active site targeted by traditional nucleoside inhibitors, at least four different allosteric-binding sites have been reported for the HCV polymerase, which offer ample opportunities for small-molecule inhibitors. In this review, we summarize the recent progress in the discovery of non-nucleoside HCV polymerase inhibitors with a focus on novel chemical matters, their clinical efficacy, safety and potential for combination therapy.

Discovery of tricyclic 5,6-dihydro-1H-pyridin-2-ones as novel, potent, and orally bioavailable inhibitors of HCV NS5B polymerase

A novel series of non-nucleoside small molecules containing a tricyclic dihydropyridinone structural motif was identified as potent HCV NS5B polymerase inhibitors. Driven by structure-based design and building on our previous efforts in related series of molecules, we undertook extensive SAR studies, in which we identified a number of metabolically stable and very potent compounds in genotype 1a and 1b replicon assays. This work culminated in the discovery of several inhibitors, which combined potent in vitro antiviral activity against both 1a and 1b genotypes, metabolic stability, good oral bioavailability, and high C(12) (PO)/EC(50) ratios.