A study of the reactions of certain nitroolefins with disubstituted diazo compounds, and subsequent decomposition of the resulting nitropyrazolines has been made. Loss of nitrous acid from the nitropyrazolines is accompanied by group migrations to carbon, resulting in the formation of 3, 4, 5-trisubstituted pyrazoles. The pyrazoles are postulated to arise from either a concerted twofold rearrangement of the Wagner-Meerwein type, or from a single ...
