Abstract
An efficient and environmentally friendly method has been developed for synthesis of 4,4′-(arylmethylene)bis(1H-pyrazol-5-ols) by condensation reaction of aromatic aldehydes with 3-methyl-l-phenyl-5-pyrazolone in the presence of phosphomolybdic acid as a recyclable catalyst in ethanol at ambient temperature in excellent yields.
GRAPHICAL ABSTRACT
ACKNOWLEDGMENTS
The author is thankful to SAIF, Indian Institute of Technology, Mumbai, for providing the spectral facility and the University Grants Commission for providing a research fellowship.
Notes
a Reaction conditions: Benzaldehyde (0.01 mol), 3-methyl-l-phenyl-5-pyrazolone (0.02 mol), phosphomolybdic acid (10 mol%), and solvent (5 vol).
b Yield: isolated.
a Reaction conditions: benzaldehyde (0.01 mol), 3-methyl-l-phenyl-5-pyrazolone (0.02 mol), phosphomolybdic acid (mol%), and solvent (5 vol).
b Yield: isolated.
a Reaction condition: aldehyde (0.01 mol), 3-methyl-1-phenyl-5-pyrazolone (0.02 mol), phosphomolybdic acid (10 mol%), and ethanol (5 vol) at rt.
b Yield: isolated.