PYRIMIDINE ACYCLONUCLEOSIDE DERIVATIVES

摘要

The present invention relates to novel pyrimidine acyclonucleoside derivatives represented by general formula (I), antiviral agents containing the derivatives as the active ingredients and processes of preparation therefor. In formula (I), R1 represents ethyl group or isopropyl group; R2 represents phenylselenenyl group, optionally substituted with one or more suitable substituents selected from C1-C3 alkyl group or halogen atom; R3 represents hydrogen atom, C1-C3 alkyl group, C1-C3 hydroxyalkyl group, acyloxyalkyl group, or phenyl group that is optionally substituted with one or more suitable substituents selected from C1-C3 alkyl group, C1-C3 alkoxy group or halogen atom; X represents oxygen atom or sulfur atom; and Y represents oxygen atom or methylene; with the proviso that R1 does not represent ethyl group when R2 represents phenylselenenyl group, R3 represents methyl group, and X and Y represent oxygen atom.