Table 3.

Structure–activity relationship of the 2′-deoxy-2′-a-fluoro-β-C-methyluridine-5′-monophosphate analogue.

R1	R2	R3	EC90	Inhibition of cellular rRNA replication at 50 μM (%)
Methyl	Isopropyl	Phenyl	0.52	25.9
Methyl	Methyl	Phenyl	1.62	0.0
Methyl	c-Hexyl	Phenyl	0.25	61.1
Methyl	Ethyl	4-F- Phenyl	0.76	55.3
Methyl	Isopropyl	4-F- Phenyl	0.77	0.0
Methyl	Isopropyl	4-Cl- Phenyl	0.42	0.0
Methyl	c-Hexyl	4-Cl- Phenyl	0.04	52.1