CAS 83747-21-1 appears in our catalog under these names: 3-(1,1-Dioxido-3-oxo-1,2-benzisothiazol-2(3h)-yl)propanoic acid, 96%, 3-(1,1,3-Trioxo-1,3-dihydrobenzo[d]isothiazol--2-yl)-propionic acid. Offered by: Combi-blocks, Fluorochem. Available pack sizes: 1g, 5g.