CAS 51891-85-1 appears in our catalog under these names: 4-(1H-Pyrazol-1-yl)benzenesulfonamide, 98%, 4-(1H-Pyrazol-1-yl)benzenesulfonamide, 95%, 4-(1H-Pyrazol-1-yl)benzenesulfonamide, 95%, 95%. Offered by: Combi-blocks, AmBeed, Fluorochem, Chemat. Available pack sizes: 25g, 5g, 1g, 100mg, 250mg, 500mg.