4-(Carbethoxynitrosamino)-1-(3-pyridyl)-1-butanone 4-(N-Carbethoxy-N-nitrosamino)-1-(3-pyridyl)-1-butanone 68743-68-0 BRN 0424393 CCRIS 2729 Carbamic acid, nitroso(4-oxo-4-(3-pyridyl)butyl)-, ethyl ester Ethyl nitroso(4-oxo-4-(3-pyridyl)butyl)carbamate