Synthesis of 1-chloro-1-[N-15]nitrosocyclohexane, an electrophilic aminating reagent.

We have prepared 1-chloro-1-[N-15]nitrosocyclohexane, an electrophillic aminating reagent useful for the stereoselective synthesis of alpha-[N-15]amino acids. Treatment of potassium [N-15]nitrate with Pb-o gave potassium [N-15]nitrite, which was converted into the intermediate hydroxylamine disulfonate by treatment with sodium bisulfite and sulfur dioxide. Addition of an excess of cylohexanone followed by heating gave a mixture of the cyclohexanone [N-15]oxime and unreacted cyclohexdanone which was removed in vacuo. The resulting [N-15]oxime was then converted to 1-chloro-1-[N-15]nitrosocyclohexane in essentially quantitative yield by treatment with chlorine gas.