CAS 28491-52-3 appears in our catalog under these names: 5-amino-1,2-dihydropyrazol-3-one, 97%, 5–Amino–1H–pyrazol–3(2H)–one, 5-Amino-1H-pyrazol-3(2H)-one 98%, 5-Amino-1H-pyrazol-3(2H)-one, 97%, 5-Amino-1H-pyrazol-3(2H)-one, 98%, 98%. Offered by: Combi-blocks, GLPBio, Ambeed, Fluorochem, Chemat. Available pack sizes: 25g, 5g, 100g, 500g, 1g, 10g.