It has been reported previously that treatment of arylketone-derived arylsulfonylhydrazones
with NXS/(nBu)4NX affords exclusively vinyl halides. In contrast, we have found that treatment of
arylaldehyde-derived arylsulfonylhydrazones with N-chlorosuccinimide in the presence of potassium hydroxide affords 1,2,4,5-tetrazine
derivatives in good to excellent yields. The present reactions are carried out under
metal-free and mild reaction conditions.
Key words
1,2,4,5-tetrazines - hydrazones -
N-chlorosuccinimide - chlorination - metal-free