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

To compound 3a (30 mg, 0.048 mmol) was added 0.5 mL 7N NH3 solution in methanol. After 1 h, the reaction solvent was removed under positive N2 atmosphere and the resulting solid was further dried under high vacuum. The reaction crude was then treated with 30 µL HCl in 300 µL THF and stirred overnight. Excess NaHCO3 was added to neutralize the reaction, followed by the addition of 1 mL MeOH. The resulting suspension was filtered through a short Celite pad, rinsed with MeOH, and concentrated. The resulting crude was then resuspended with 1 mL H2O and subjected to HPLC purification with a linear gradient of 5-20% MeCN (0.1% TFA) in H2O (0.1% TFA) on a prep C18 column (Agilent 10 prep-C18 250 ´ 21.1 mm). Fractions containing desired products was then combined and lyophilized to afford the final product 4a (4.6 mg, 0.019 mmol, 40%) as white powder. In a similar manner, compound 1 (360 mg, 0.85 mmol, 1 equiv.) was reacted with 2b (238 mg, 1.02 mmol, 1.2 equiv.) to afford intermediate 3b as white powder (288 mg, 0.45 mmol, 53%). Intermediate 3b (32 mg, 0.05 mmol) was then deprotected to afford 4b (7.7 mg, 0.03 mmol, 60%) as white powder. The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi.org/10.1101/2020.03.24.992230 doi: bioRxiv preprint