1-(5'-Fluoro-6'-hydroxy-5',6'-dihydrouracil-5'-yl)-5-fluorouracil 5-Fluoro-5-(5-fluoro-2,4-dioxo-3,4-dihydro-1(2H)-pyrimidinyl)-6-hydroxydihydro-2,4(1H,3H)-pyrimidinedione AIDS-143408 AIDS143408 NSC664145