β-Ketonitrosamines. Synthetic Equivalents of α-Methylene Alkylamino Anions (⁻CH₂NHR)

Abstract

β-Ketonitrosamines are important in the study of nitrosamine metabolism, carcinogenesis and in vivo alkylation. The enhanced acidity of protons at the α-carbon, as well as the ease of fragmentation of the title compounds establishes them as synthetic equivalents of α-methylene alkylamino anions (⁻CH₂NHR). Anion formation is carried out with powered sodium hydroxide-sodium carbonate in DMF or THF at 25°C. Reaction with an alky halide gives a good yield of the alkylated product. Retro-Claisen cleavage in aqueous basic media gives the corresponding dialkyl-nitrosamine or, with D₂O, the deuterated analog.