CAS 21731-57-7 appears in our catalog under these names: 4-Methanesulfonylbenzene-1,2-diamine, 98%, 4-(Methylsulfonyl)benzene-1,2-diamine, 98%, 4-(Methylsulfonyl)benzene-1,2-diamine, 98%(LC-MS),RG, 98%(LC-MS),RG, 4-(Methylsulfonyl)benzene-1,2-diamine. Offered by: Combi-blocks, AmBeed, Chemat, Fluorochem. Available pack sizes: 250mg, 5g, 10g, 1g, 100mg.