134250-26-3 (R) 134250-46-7 (S) 3'-Azido-3'-deoxythymidine-5'-(ethyl methoxy-4-aminobutyl)phosphoramidate AIDS-002289 AIDS002289 MeOCOPrNHPO3(Et)AZT Thymidine, 3'-azido-3'-deoxy-, 5'-[ethyl (4-methoxy-4-oxobutyl)phosphoramidate], -