Patent ID: 8691788

Claim:
A compound of the formula: or a pharmaceutically acceptable salt, or a stereoisomeric or tautomeric form thereof, wherein: R y is optionally substituted alkyl, alkenyl, alkynyl, aryl, arylalkyl, cycloalkyl, cycloalkenyl, hydroxyalkyl, amino, heterocyclyl or heteroaryl; R a and R b are selected as follows: i) R a and R b are each independently hydrogen or optionally substituted alkyl, carboxyalkyl, hydroxyalkyl, hydroxyarylalkyl, acyloxyalkyl, aminocarbonylalkyl, alkoxycarbonylalkyl, aryl, arylalkyl, cycloalkyl, heteroaryl or heterocyclyl; or ii) R a and R b together with the nitrogen atom on which they are substituted form a 3-7 membered heterocyclic or heteroaryl ring; and R 1 is selected from the group consisting of ribavirin, viramidine, valopicitabine, PSI-6130, MK-0608, resiquimod and celgosivir, lamivudine, entecavir, telbivudine, racivir, emtricitabine, clevudine, amdoxovir, valtorcitabine, tenofovir and adefovir.