Patent ID: 7192936

Claim:
A method for the treatment of a host infected with a Flaviviridae virus, comprising administering an effective treatment amount of a compound or a pharmaceutically acceptable salt thereof, wherein the compound has the formula or a pharmaceutically acceptable salt thereof, wherein: R 1 is H; mono, di or triphosphate; acyl; an amino acid ester; a carbohydrate; a peptide; or a pharmaceutically acceptable leaving group which when administered in vivo provides a compound wherein R 1 is H or phosphate; R 2 is hydrogen, acyl; an amino acid ester; a carbohydrate; a peptide; or a pharmaceutically acceptable leaving group which when administered in vivo provides a compound wherein R 2 is H; Y 1 is OH, OR 4 , NH 2 , NHR 4 , NR 4 R 5 ; X 1 is a H, CH 3 or fluoro; and each R 4 and R 5 is independently hydrogen, acyl, alkyl, lower alkyl alkenyl, alkynyl or cycloalkyl.