5-Methyl-1-{5-[(6-nitro-2-oxo(4H-benzo[e]1,3,2-dioxaphosphan-2-yloxy))methyl](2-2,5-dihydrofuryl)}-1,3-dihydropyrimidine-2,4-dione AIDS-045046 AIDS045046 CycloSal-d4TMP