1-(Cyanoacetyl)-3,5-dimethylpyrazole as an effective alternative to cyanoacetic ester in the synthesis of 2,6-dioxopiperidine-3,5-dicarbonitrile derivatives
1-(Cyanoacetyl)-3,5-dimethylpyrazole reacted with 2-cyanoacrylamides in the presence of triethylamine with the formation of triethylammonium salts of 4-monosubstituted-2,6-dioxopiperidine-3,5-di-carbonitriles (Guareschi imides) or the products of their oxidation, the 4-aryl-3,5-dicyano-6-oxo-1,6-di-hydropyridin-2-olates.