A convenient approach for the synthesis of 4,4'-((substituted phenyl)methylene)bis(3-methyl-1H-pyrazol-5-ol) and their antioxidant and antimicrobial activities

Abstract

A facile one-pot, three component, convenient approach for the synthesis of 4,4'-((substituted phenyl)methylene)bis(3-methyl-1H-pyrazol-5-ol) derivatives (3a–l) has been accomplished from the reaction of two moles of 5-methyl-2,4-dihydro-3H-pyrazol-3-one (1), with one mole various aromatic aldehydes (2a–l) in the presence ZnO nanoparticles as an efficient heterogeneous catalyst under microwave irradiation (MWI) and solvent-free conditions in good to excellent yields. The major advantages of the present method are, short reaction times, magnetically recyclable catalyst and high yields. The newly synthesized compounds were synthesized and characterized by melting point, IR, NMR, mass spectra. Furthermore the compounds were evaluated for their antioxidant and antimicrobial activities which showed good activities when compared to standards.

Graphical Abstract

Keywords:

• Antimicrobial activity
• antioxidant activity
• bispyrazolyl methanes
• microwave irradiation
• solvent free
• ZnO nanoparticles

Acknowledgments

The authors acknowledge Department of Chemistry, Krishna University, Machilipatnam, A.P., India for providing necessary infrastructure and laboratory facilities and render their thanks to DST-P URSE 2nd Phase Programme in S.V. University, Tirupati, funded by DST, New Delhi, India for providing instrumental analysis.