Patent ID: 7384924

Claim:
A method for the treatment of a Flaviviridae virus infection in a host infected with a Flaviviridae virus comprising administering an effective treatment amount of a compound of formula or a pharmaceutically acceptable salt thereof wherein R 1 is H; phosphate; acyl; an amino acid ester; a carbohydrate; a peptide; or pharmaceutically acceptable leaving group which when administered in vivo provides a compound wherein R 1 is H or phosphate; R 2 is H; acyl; an amino acid ester; a carbohydrate; a peptide; or pharmaceutically acceptable leaving group which when administered in vivo provides a compound wherein R 1 is H or phosphate; X* is CH, CF CY 3 or CR 4 ; Y 3 is independently H, or F; R 4 is hydrogen, acyl, alkyl, lower alkyl, alkenyl or cycloalkyl; Base is a pyrimidine base; R 12 is C(Y 3 ) 3 ; and, R 13 is OR 4 or fluoro.