Synthesis of pyrazolo[3,4-b]pyridines using ammonium acetate as green reagent in multi-component reactions

摘要

Several new pyrazolo[3,4-b]pyridine derivatives were synthesized by one pot cyclocondensation of the components; 5-amino-3-aryl-1H-phenylpyrazoles, p-substituted benzoylacetonitriles and some aldehydes. The condensations were most effective by using ammonium acetate as the base catalyst; triethylamine was also studied as a catalyst.