PHOSPHONATE NUCLEOTIDE DERIVATIVES

摘要

A compound represented by general formula (I) and having an antiviral activity, wherein R<1> represents hydrogen, C1-6 alkyl or C7-10 aralkyl; R<2> represents C1-6 alkyl, C7-10 aralkyl or phenyl; R<3> and R<4> independently represent each hydrogen, C1-6 alkyl, acyloxymethyl, acylthioethyl or ethyl substituted by at least one halogen atom; R<5> represents hydrogen, C1-4 alkyl, C1-4 hydroxyalkyl or C1-4 alkyl substituted by at least one halogen atom; and X represents carbon or nitrogen.