Bicyclic pyrimidinones and uses thereof

A method of treatment or prophylaxis of a viral infection in a subject comprising administering to said subject an effective amount of a compound of Formula II or a pharmaceutically acceptable salt or prodrug thereof wherein:

• X is selected from the group consisting of O and S;
• Y is selected from the group consisting of O and S;
• R1 is 0-3 substituents each of which is independently selected from the group consisting of CN, C1-10alkyl, C2-10alkenyl, C1-10alkylPO3H2, —O—C1-10alkyl, C1-10alkylNR3R4, —O—C1-10alkylNR3R4, halo, NR3R4, alkylaryl, alkylheteroaryl, aryl, heteroaryl, —O-alkylaryl, SO2NR3R4;
• R3 and R4 are each independently selected from the group consisting of hydrogen, CO2C1-4alkyl, C(O)C1-4alkyl, C1-10alkyl, C1-10NR5R6, —NH(CO)(CO)NHC1-4alkyl;
• or R3 and R4 taken together with the attached nitrogen form a 5-7 membered heterocyclic ring which contains zero to two additional heteroatoms selected from N, O or S where S can be at the S, S(O) or S(O)2 oxidation state and wherein said heterocyclic ring is optionally substituted at the carbon or nitrogen atoms with one or more substituents selected from halo, aryl, C(O)C1-4alkyl, SO2C1-4alkyl, SO2H, C1-4alkyl, CO2H, CO2C1-4alkyl, NR5R6;
• C1-4alkylNR5R6;
• R5 and R6 are each independently selected from the group consisting of H, and C1-4alkyl or R5 and R6 together with the attached nitrogen form a 5-7 membered heterocyclic ring which contains zero to two additional heteroatoms selected from N, O or S where S can be at the S, S(O) or S(O)2 oxidation state and wherein said heterocyclic ring is optionally substituted at the carbon or nitrogen atoms with one or more substituents selected from halo and C1-4alkyl;
• when R1 is alkylaryl or —O-alkylaryl, the aryl group of said alkylaryl substituent is optionally substituted with a substituent selected from C1-10alkyl, —O—C1-10alkyl, C1-10alkylNR3R4, —O—C1-10alkylNR3R4, halo, NR3R4, alkylaryl, —O-alkylaryl, SO2NR3R4
• B is absent;
• C is absent;
• R2 is selected from the group consisting of heteroaryl, and heterocyclyl.