1H-Pyrazolo[4,3-d]pyrimidin-7-amine, N-(3-methyl-2-butenyl)-3-.beta.-D-ribofuranosyl- 1H-Pyrazolo[4,3-d]pyrimidine, 7-[(3-methyl-2-butenyl)amino]-3-.beta.-D-ribofuranosyl- 33987-26-7 N7-(.DELTA.2-Isopentenyl)formycin NSC175628