| abstract |
A phosphonate nucleotide compound having antiviral activity and is useful for an orally available and highly safe antiviral agent, which is represented by the following formula (I): <IMAGE> (I) wherein R1 represents hydrogen, a C1-C6 alkoxy, a halogen-substituted C1-C4 alkoxy, halogen, amino, or nitro; R2 and R3 independently represent hydrogen, a C1-C22 alkyl, an acyloxymethy, an acylthioethyl, or a halogen-substituted ethyl; R4 represents hydrogen, a C1-C4 alkyl, a C1-C4 hydroxyalkyl, or a halogen-substituted C1-C4 alkyl; and X represents carbon or nitrogen. |