Purine nucleoside analogues for treating flaviviridae including hepatitis c

Abstract From the Canadian patent

This invention is directed to a method for treating a host especially a , human, infected with , hepatitis C flavivirus and/or pestivirus, comprising administering to that host an effective , amount of an anti-HCV biologically active pentofuranonucleoside where the pentofuranonucleoside base is an optionally substituted 2-azapurine. The optionally substituted , pentofuranonucleoside or a salt or prodrug thereof, may be administered alone or in combination , with one or more optionally substituted pentofuranonucleosides or other antiviral agents. In a , principal embodiment the pentofuranonucleoside is of Formula (I): (see formula I) , wherein R, R1, R1', R2 R2', R3, R3', X and Base are …