1-{5-[(6-Chloro-2-oxo(4H-benzo[e]1,3,2-dioxaphosphan-2-yloxy))methyl](2-2,5-dihydrofuryl)}-5-methyl-1,3-dihydropyrimidine-2,4-dione AIDS-045047 AIDS045047 CycloSal-d4TMP