The synthesis of 3-diazo-2-nitromethylenepiperidine

The synthesis of 3-diazo-2-nitromethylenepiperidine, in six steps from 2-piperidone, is reported. This is the first compound described which contains the 3-diazo-1-nitropropene function. The title compound is stable enough to be isolated and characterised in gram quantities using standard organic chemistry techniques and was used to prepare some 5-aza-spiro[2.5]octane and 4,5,6,7-tetrahydro-1H-pyrazolo-[4,3-b]pyridine derivatives.