Synthesis of Polysubstituted Pyrazolo[3,4‐<i>b</i>]pyridine‐3‐Carbohydrazide and Pyrazolo[3,4‐<i>d</i>]pyridazine Derivatives

Abstract

5‐Amino‐4‐formyl pyrazole carboxylate gave facile reactions with malononitrile, hydrazine, and ketones in the presence of piperidine furnished substituted pyrazolo[3,4‐ b ]pyridines and pyrazolo[3,4‐ b ]quinolones. The pyridazine sulfonamides were obtained by the reaction of 5‐chloro 4‐formyl pyrazole carboxylate with sulfonamide derivatives.