CAS 272-57-1 appears in our catalog under these names: 1H–Pyrazolo, 1H-Pyrazolo[4,3-d]pyrimidine 95%, 1H-pyrazolo[4,3-d]pyrimidine, 95%, 95%, 1h-Pyrazolo[4,3-d]pyrimidine, 95%. Offered by: GLPBio, Ambeed, Chemat, Fluorochem. Available pack sizes: 100mg, 250mg, 1g, 5g.