Substituted Pyrazolo[3,4-B]Pyridin-3-Ones and Pyrazolo[3,4-B]Pyridine-5- Carbaldehyde, New One-Pot Synthesis Strategy Amelioration Using Vinamidinium Salts, Antibacterial and Antifungal Activities Promising Environmental Protection

Abstract

This review summarizes the current knowledge about the syntheses and biological behavior of some pyrazolo[5,4-b]pyridines. So, an expedient method for the synthesis of 2-phenyl-5-aryl-1,6-dihydropyrazolo[3,4- b]pyridin-3-ones and 2-phenyl-3-oxo-1,6-dihydropyrazolo[3,4-b]pyridine-5-carbaldehyde in a single-step via condensation of vinamidinium salts with 3-amino-1-phenyl-2-pyrazolin-5-one is described according to our recent study with synthesis strategy amelioration. Five derivatives (PYR1-5) were prepared and characterized by spectral data (NMR and MS spectral studies). All the derivatives were studied for their antimicrobial activities. So, we screened for antibacterial effects at 1:2, and 1:4 dilutions by the paper disc diffusion method against respectively Bacteria (Escherichia coli CIP 53126 and Bacillus subtilis CIP 5262) and Fungi (Candida albicans ATCC 10231). Then, we screened for Fungi (Aspergillus niger ATCC 16404) by the dilution method (agar and liquid broth). The agar diffusion method (paper disc and well) and the dilution method (agar and liquid broth) are described.