Nucleoside phosphoramidate prodrugs

A compound of formula IA:

• or a stereoisomer thereof, wherein:
• R1 is naphthyl;
• R2 is H or C1-10 alkyl, or R2 together with R3a or R3b are (CH2)n so as to form a cyclic ring that includes the adjoining N and C atoms, where n is 2 to 4;
• R3a and R3b are (i) independently selected from H, C1-10 alkyl, cycloalkyl, —(CH2)c(NR3′)2, C1-6 hydroxyalkyl, —CH2SH, —(CH2)2S(O)dMe, —(CH2)3NHC(═NH)NH2, (1H-indol-3-yl)methyl, (1H-imidazol-4-yl)methyl, —(CH2)eCOR3″, aryl and aryl C1-3 alkyl, said aryl groups optionally substituted with a group selected from hydroxyl, C1-10 alkyl, C1-6 alkoxy, halogen, nitro and cyano;
• (ii) R3a and R3b both are C1-6 alkyl;
• (iii) R3a and R3b together are (CH2)f so as to form a spiro ring;
• (iv) R3a is hydrogen and R3b and R2 together are (CH2)n so as to form a cyclic ring that includes the adjoining N and C atoms;
• (v) R3b is hydrogen and R3a and R2 together are (CH2)n so as to form a cyclic ring that includes the adjoining N and C atoms, where c is 1 to 6, d is 0 to 2, e is 0 to 3, f is 2 to 5, n is 2 to 4, and where R3′ is independently hydrogen or C1-6 alkyl and R3 is —OR′ or —N(R3′)2;
• (vi) R3a is H and R3b is H, CH3, CH2CH3, CH(CH3)2, CH2CH(CH3)2, CH(CH3)CH2CH3, CH2Ph, CH2-indol-3-yl, —CH2CH2SCH3, CH2CO2H, CH2C(O)NH2, CH2CH2COOH, CH2CH2C(O)NH2, CH2CH2CH2CH2NH2, —CH2CH2CH2NHC(NH)NH2, CH2-imidazol-4-yl, CH2OH, CH(OH)CH3, CH2((4′-OH)-Ph), CH2SH, or lower cycloalkyl;
• or (viii) R3a is CH3, —CH2CH3, CH(CH3)2, CH2CH(CH3)2, CH(CH3)CH2CH3, CH2Ph, CH2-indol-3-yl, —CH2CH2SCH3, CH2CO2H, CH2C(O)NH2, CH2CH2COOH, CH2CH2C(O)NH2, CH2CH2CH2CH2NH2, —CH2CH2CH2NHC(NH)NH2, CH2-imidazol-4-yl, CH2OH, CH(OH)CH3, CH2((4′-OH)-Ph), CH2SH, or lower cycloalkyl and R3b is H, where R3′ is independently H or alkyl and R3″ is —OR′ or —N(R3′)2;
• R4 is H or C1-10 alkyl optionally substituted with a lower alkyl, alkoxy, di(lower alkyl)amino, or halogen, C1-10 haloalkyl, C3-10 cycloalkyl, cycloalkyl alkyl, cycloheteroalkyl, aminoacyl, optionally substituted aryl or optionally substituted heteroaryl;
• R5 is CH2CN, CH2NH2, CH2NHCH3 or CH2N(CH3)2;
• R6 is H, CH3, CH2F, CHF2, CF3, F or CN;
• X is H, OH, OCH3, halogen, NH2, or N3;
• Y is OH, H, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, vinyl, N3, CN, Cl, Br, F, I, NO2, OC(O)O(C1-4 alkyl), OC(O)O(C1-4 alkyl), OC(O)O(C2-4 alkynyl), OC(O)O(C2-4 alkenyl), OC1-10 haloalkyl, O(aminoacyl), acyl), O(C1-4 alkyl), O(C2-4 alkenyl), S(C1-4 acyl), S(C1-4 alkyl), S(C2-4 alkynyl), S(C2-4 alkenyl), SO(C1-4 acyl), SO(C1-4 alkyl), SO(C2-4 alkynyl), SO(C2-4 alkenyl), SO2(C1-4 acyl), SO2(C1-4 alkyl), SO2(C2-4 alkynyl), SO2(C2-4 alkenyl), OS(O)2(C1-4 acyl), OS(O)2(C1-4 alkyl), OS(O)2(C2-4 alkenyl), NH2, NH(C1-4 alkyl), NH(C2-4 alkenyl), NH(C2-4 alkynyl), NH(C1-4 acyl), N(C1-4 alkyl)2, N(C1-18 acyl)2, wherein alkyl, alkynyl, alkenyl and vinyl are optionally substituted by N3, CN, one to three halogen, NO2, C(O)O(C1-4 alkyl), C(O)O(C1-4 alkyl), C(O)O(C2-4 alkynyl), C(O)O(C2-4 alkenyl), O(C1-4 acyl), O(C1-4 alkyl), O(C2-4 alkenyl), S(C1-4 acyl), S(C1-4 alkyl), S(C2-4 alkynyl), S(C2-4 alkenyl), SO(C1-4 acyl), SO(C1-4 alkyl), SO(C2-4 alkynyl), SO(C2-4 alkenyl), SO2(C1-4 acyl), SO2(C1-4 alkyl), SO2(C2-4 alkynyl), SO2(C2-4 alkenyl), OS(O)2(C1-4 acyl), OS(O)2(C1-4 alkyl), OS(O)2(C2-4 alkenyl), NH2, NH(C1-4 alkyl), NH(C2-4 alkenyl), NH(C2-4 alkynyl), NH(C1-4 acyl), N(C1-4 alkyl)2 or N(C1-4 acyl)2;
• R7, R8 and R9 are independently H, F, Cl, Br, I, OH, OR′, SH, SR′, NH2, NHR′, NR′2, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 haloalkenyl, C2-6 alkynyl, C2-6 haloalkynyl, C1-6 alkoxy, C1-6 haloalkoxy, CO2H, CO2R′, CONH2, CONHR′, CONR′2, CH═CHCO2H, or CH═CHCO2R′,
• wherein R′ is an optionally substituted alkyl, an optionally substituted cycloalkyl, an optionally substituted C2-6 alkynyl, an optionally substituted C2-6 alkenyl, or an optionally substituted acyl, or in the instance of NR′2, each R′ comprise at least one C atom that are joined to form a heterocycle comprising at least two carbon atoms;
• and