Enhancing the Antiviral Efficacy of RNA-Dependent RNA Polymerase Inhibition by Combination with Modulators of Pyrimidine Metabolism

Qi Liu; Amita Gupta; Ayse Okesli-Armlovich; Wenjie Qiao; Curt R. Fischer; Mark Smith; Jan E. Carette; Michael C. Bassik; Chaitan Khosla

Unless otherwise noted, all reactions were performed under an argon atmosphere in flame-or oven-dried glassware. Reaction mixtures were stirred using Teflon-coated magnetic stirrer bars and monitored by thin layer silica gel chromatography (TLC) using 0.25 mm silica gel 60F plates with fluorescent indicator from Merck. Plates were visualized under UV or treated by KMnO4 stain with gentle heating. Products were purified on an AnaLogix IntelliFlash 280 Flash column chromatography system using the solvent gradients indicated. Anhydrous tetrahydrofuran (THF), dichloromethane (CH2Cl2), dimethylformamide (DMF), acetone, and dimethyl sufoxide (DMSO) were obtained from Acros Organics. Diethyl ether (Et2O), ethyl acetate (EtOAc), hexanes, and methanol (MeOH) were from Fisher Scientific. DMSO used in bioassays and to prepare biological samples was from Fisher BioReagents. All other reagents were from commercial suppliers and were used as received without additional purification. Samples prepared for biological evaluation were purified via preparative HPLC in a water/acetonitrile (MeCN) gradient containing 0.1% (v/v) trifluoracetic acid (TFA) using an Agilent 1260 Infinity system equipped with an Agilent Prep-C18 column (21.2 x 250 mm).