Phosphonate-nucleotide ester derivatives

摘要

Phosphonate-nucleotide ester compounds of the formula (I) have excellent antiviral activity and antineoplastic activity. Further, they can be orally administered. wherein ring A represents wherein R1 and R2 independently represent hydrogen, halogen, hydroxyl, mercapto, C6-C10 arylthio or amino; R3 represents C1-C4 alkyl or ethyl having one or more substituents selected from the group consisting of fluorine, C1-C4 alkoxy, phenoxy, C7-C10 phenylalkoxy and C2-C5 acyloxy; R4 represents ethyl having one or more substituents selected from the group consisting of fluorine, C1-C4 alkoxy, phenoxy, C7-C10 phenylalkoxy and C2-C5 acyloxy; X, Y and Z independently represent methyne or nitrogen atom; or a pharmaceutically acceptable salt thereof.