Structure-activity relationship study on a novel series of cyclopentane-containing macrocyclic inhibitors of the hepatitis C virus NS3/4A protease leading to the discovery of TMC435350.

SAR analysis performed with a limited set of cyclopentane-containing macrocycles led to the identification of N-[17-[2-(4-isopropylthiazole-2-yl)-7-methoxy-8-methylquinolin-4-yloxy]-13-methyl-2,14-dioxo-3,13-diazatricyclo [13.3.0.0(4,6)]octadec-7-ene-4-carbonyl](cyclopropyl)sulfonamide (TMC435350, 32c) as a potent inhibitor of HCV NS3/4A protease (K(i)=0.36nM) and viral replication (replicon EC(50)=7.8nM). TMC435350 also displayed low in vitro clearance and high permeability, which were confirmed by in vivo pharmacokinetic studies. TMC435350 is currently being evaluated in the clinics.