CAS 3201-28-3 appears in our catalog under these names: 1,5-Dimethyl-1H-pyrazol-3(2H)-one, 97%, 1,5-Dimethyl-2,3-dihydro-1H-pyrazol-3-one, 1,5-Dimethyl-1H-pyrazol-3(2H)-one, 95%, 95%, 1,5-Dimethyl-2,3-dihydro-1H-pyrazol-3-one, 97%, Dimethylpyrazolon (DP). Offered by: AmBeed, TRC, Chemat, Fluorochem, HPC Standards. Available pack sizes: 1g, 500mg, 5g, 10g, 25g, 50mg, 100mg, 1x25mg.