N″-sulphonylformamidrazones; preparation and characterisation

N′-Sulphonylformamidrazones have been prepared in good yields from the reaction between N-sulphonylformimidates and di- or tri-substituted hydrazines.The actual tautomeric form present has been shown to be a hydrazide imide by ¹³C NMR spectroscopy. ¹H and ¹³C NMR spectra showed the existence of a cis and a trans isomer in solution, arising from hindered rotation around the CN¹ bond.