CAS 24521-76-4 appears in our catalog under these names: 4-Hydroxy-6-mercaptopyrazolo(3,4-d)pyrimidine, 4-Hydroxy-6-mercaptopyrazolo[3,4-d]pyrimidine, 95%, 6-Mercapto-1H,5H,7H-pyrazolo[3,4-d]pyrimidin-4-one, 95%, 6-MERCAPTO-4-HYDROXY-1H-PYRAZOLO[3,4-D]PYRIMIDINE, 95%. Offered by: Biosynth, Combi-blocks, Fluorochem. Available pack sizes: 500mg, 1000mg, 5g, 1g, 250mg, 10g.