1-Butyl-3,3-dimethyl-1-nitrosourea 3,3-Dimethyl-1-butyl-1-nitrosourea 56654-53-6 BRN 2442171 CCRIS 2431 N-Butyl-N',N'-dimethyl-N-nitrosourea Urea, 1-butyl-3,3-dimethyl-1-nitroso-