PHOSPHONATE NUCLEOTIDE COMPOUNDS

摘要

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): <IMG> 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-C2 2 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.