CAS 418805-02-4 appears in our catalog under these names: Ethyl 4-(4-((5-nitrofuran-2-yl)methylene)-3,5-dioxopyrazolidin-1-yl)benzoate, 98%, 98%, PYR-41, >95% (HPLC), PYR-41/ 99.24% (existing batch purity), PYR–41, Ubiquitin E1 Inhibitor, PYR-41 . Offered by: Chemat, TRC, TargetMol, GLPBio, Thermo Scientific (Alfa Aesar). Available pack sizes: 5mg, 10mg, 25mg, 50mg, 100mg, 250mg, 1mg, 2mg.