4-Amino-1-((2R,3S,4S,5R)-5-azido-3,4-dihydroxy-5-hydroxymethyl-tetrahydro-furan-2-yl)-
1
H-pyrimidin-2-one (I:R
1
=R
2
=R
3
=R
4
=H) and prodrugs thereof are hepatitis C(HCV) polymerase inhibitors. Also disclosed are compositions and methods for inhibiting HCV and treating HCV-mediated diseases, processes for making the compounds and synthetic intermediates employed in the process.
The present invention relates to a one-step process for the selective O-acylation of the hydroxy groups of a nucleoside under basic conditions utilizing DMAP and a carboxylic acid anhydride in aqueous heterogenous solvent mixture.