Synthesis of an HCV RNA Polymerase Inhibitor

Significance

The target molecule, an HCV RNA polymerase (NS5B) inhibitor, was synthesized in twelve steps on a multigram scale (9% overall yield). The synthesis features the late-stage introduction of the 6-amino group in the 7-deazapurine moiety via a mild S_NAr reaction using NaN₃ (H → I), followed by a chemoselective Staudinger reaction in the penultimate step.