5-24-05-00291 (Beilstein Handbook Reference) 69000-73-3 BRN 0900789 N-(2-Chloroethyl)-N'-(4-(4-ethyl-2,3-dioxo-1-piperazinyl)butyl)-N-nitrosourea Urea, N-(2-chloroethyl)-N'-(4-(2,3-dioxo-4-ethyl-1-piperazinyl)butyl)-N-nitroso-