(S)-2-(2-Cyano-ethoxy)-[3-fluoro-5-(5-methyl-2,4-dioxo-tetrahydro-pyrimidin-1-yl)-tetrahydro-furan-2-ylmethoxy]-phosphorylamino}-3-(1H-indol-3-yl)-propionic acid methyl ester AIDS-104752 AIDS104752 AZT Phosphoramidates