CAS 652-40-4 appears in our catalog under these names: 3,6-Difluorophthalic anhydride, 95%, 4,7-Difluoro-1,3-isobenzofurandione (Technical Grade, ~90%), 4,7-Difluoro-2-benzofuran-1,3-dione, 4,7-Difluoroisobenzofuran-1,3-dione 98%, 4,7-Difluoroisobenzofuran-1,3-dione, 98%, 98%. Offered by: Combi-blocks, TRC, Biosynth, Ambeed, Chemat. Available pack sizes: 250mg, 5g, 1g, 100mg, 500mg, 10g.