Patent ID: 7105499

Claim:
A method of treating hepatitis C virus (HCV) infection comprising administering to a mammal in need of such treatment a therapeutically effective amount of a compound of structural formula III, or a pharmaceutically acceptable salt or acyl derivatives thereof, wherein B is W is O or S; Y is H, C 1 -10 alkylcarbonyl, P 3 O 9 H 4 , P 2 O 6 H 3 , or P(O)R 9 R 10 ; R 1 is CF 3 , or C 1-4 alkyl and one of R 2 and R 3 is OH or C 1-4 alkoxy and the other of R 2 and R 3 is fluoro; R 6 is H, OH, SH, NH 2 , C 1-4 alkylamino, di(C 1-4 alkyl)amino, C 3-6 cycloalkylamino, halogen, C 1-4 alkyl, C 1-4 alkoxy, or CF 3 ; R 5 is H, C 1-6 alkyl, C 2-6 alkenyl, C 2-6 alkynyl, C 1-4 alkylamino, CF 3 , or halogen; and R 9 and R 10 are each independently hydroxy, OCH 2 CH 2 SC(═O)t-butyl, or OCH 2 O(C═O)iPr.