Microwave assisted synthesis, characterization and antimicrobial activity of novel bipyrazole derivatives

Ujjwal Sahoo¹*, Souvik Basak¹*, Rakesh Chawla ²

¹ Dr. B.C. Roy College of Pharmacy & Allied Health Sciences, Durgapur, WB, India

² University Institute of Pharmaceutical Sciences & Research, Sadiq Road, Baba Farid University of Health Sciences, Faridkot, Punjab, India

*Correspondence : sahoo.devurb@gmail.com, souvik_basak1@yahoo.com

Abstract

N'-[-1-phenylethylidene] pyridine-4-carbohydrazide (3a-f) were prepared by reacting with substituted acetophenone and iso-nicotinic acid hydrazide and were reacted with Phosphorous oxy chloride and Dimethyl formamide to yield 3-phenyl-1-(pyridin-4-ylcarbonyl)-1H-pyrazole-4-carbaldehyde (4a-f). Solution of substituted acetophenone and Pyrazole-4-carbaldehyde were reacted to obtain 1-phenyl-3-[3-phenyl-1-(pyridin-4-ylcarbonyl)-1H-pyrazol-4-yl] prop-2-en-1-one (5a-f). To Synthesize 5, 3'-diphenyl-1', 2-diisonicotinoyl-3, 4-dihydro-1'H, 2H-3, 4'-bipyrazole (6a-f), 1-phenyl-3-[3-phenyl-1-(pyridin-4-ylcarbonyl)-1H-pyrazol-4-yl] prop-2-en-1-one was reacted with iso-nicotinic acid hydrazide. Moreover, the compounds revealed antimicrobial activity together with significant antifungal activities to some extent. Compound 6f with methoxy substitution, was found to be the most potent compound of the series with antifungal activity comparable to the standard drug, Fluconazole, against A. niger. It was followed by compounds 6b and 6c which depicted significant activity against C. albicans and A. niger. Other compounds in the current research have shown moderate activity against tested antibacterial and antifungal strains.

Keywords: Bipyrazole, heterocyclic, antibacterial, antifungal, substituted acetophenone and iso-nicotinic acid hydrazide