One-pot three-component synthesis of a series of 4-aroyl-1,6-diaryl-3-methyl-1H-pyrazolo[3,4-b]pyridine-5-carbonitriles in the presence of aluminum oxide as a nanocatalyst

Abstract

One-pot three-component reaction of arylglyoxals, 3-aryl-3-oxopropanenitriles, and 5-amino-1-aryl-3-methylpyrazoles using various solvent systems and different catalysts under reflux conditions afforded the corresponding 4-aroyl-1,6-diaryl-3-methyl-1H-pyrazolo[3,4-b]- pyridine-5-carbonitrile derivatives. The best yields (70–91%) were obtained using Al2O3 as a nanocatalyst in H2O–EtOH, 1:1, under reflux conditions. The simplicity of workup procedure, the novelty of pyrazolopyridines, green solvent system, easy preparation of a nanocatalyst, and good to excellent yields of the products are the advantages of this synthetic strategy. The structures of all products were confirmed by FT-IR, 1H and13C NMR, and mass spectral data.