Synthesis of pyrazolo[3,4-b]pyridines under microwave irradiation in multi-component reactions and their antitumor and antimicrobial activities – Part 1

An efficient one-pot synthesis in multi-component system (MRCs) for the preparation of pyrazolo[3,4-b]pyridine derivatives from the reaction of 5-amino-1-phenyl-3-(pyridin-3-yl)-1H-pyrazole with 4-anisaldehyde and p-substituted β-ketonitriles or with pyruvic acid and some aromatic aldehydes in acetic acid medium. The reactions were carried out by two different techniques, conventional heating and microwave irradiation. These compounds were screened for their antibacterial activity against Gram-positive bacteria (Bacillus), Gram-negative bacteria (Escherichia coli, Enterobacter cloaca and serratia) and antifungal activity against Fusarium Oxysporum and Penicillium expansum. Also, among the synthesized compounds 4a–f tested for antitumor activity against liver cell line. Compounds 6-(4-Fluorophenyl)-4-(4-methoxyphenyl)-1-phenyl-3-(pyridin-3-yl)-1H-pyrazolo[3,4-b]pyridine-5-carbonitrile (4e) and 4-(4-Methoxyphenyl)-1-phenyl-3,6-di(pyridin-3-yl)-1H-pyrazolo[3,4-b] pyridine-5-carbonitrile (4a) showed the highest activity.

Graphical abstractSynthesis of some new pyrazolo[3,4-b]pyridine derivatives were reported. The reactions were carried out by conventional heating and microwave irradiation. Most of the synthesized compounds were screened for antimicrobial and antitumor activities.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Synthesis of 5-amino-1-phenyl-3-(pyridin-3-yl)-1H-pyrazole was reported. ► Synthesis of pyrazolo[3,4-b]pyridine derivatives by one-pot cycleocondensation reaction. ► The reactions were carried out by conventional heating and microwave irradiation. ► Most of the synthesized compounds were screened for antimicrobial and antitumor activities.