N-sulphonylformamidrazones; preparation and structure

Potentially tautomeric N-sulphonylformamidrazones and models with fixed amide-hydrazone and hydrazide-imide structure have been prepared. The compounds with tautomeric possibilities have been shown to exist only in the amide-hydrazone form by ¹³C and ¹H NMR spectroscopy. The same compounds exist as two rotamers in solution arising hindered rotation around the NCHN single bond.