1H-Pyrazolo[3,4-d]pyrimidine-3-carboxylic acid, 6-amino-4,5-dihydro-4-oxo-1-.beta.-D-ribofuranosyl- 6-Amino-3-carboxy-1-.beta.-D-ribofuranosylpyrazolo[3,4-d]pyrimidin-4(5H)-one 96555-48-5 AIDS-001494 AIDS001494 Pyrazolopyrimidine nucleoside