Xanthan Sulfuric Acid: An Efficient, Biosupported, and Recyclable Solid Acid Catalyst for the Synthesis of 4,4′-(Arylmethylene)bis(1H-pyrazol-5-ols)

Abstract

A simple and efficient method has been developed for the synthesis of 4,4′-(arylmethylene)bis(1H-pyrazol-5-ols) by the condensation reaction between substituted aldehydes, and 1-phenyl-3-methylpyrazol-5-one in the presence of xanthan sulfuric acid (XSA) as a solid acid catalyst. This method is simple and cost-effective with short reaction times. Yields are excellent with high purity, and the catalyst could be easily recycled.

GRAPHICAL ABSTRACT

Keywords:

• Aldehydes
• 4,4′-(arylmethylene)bis(1H-pyrazol-5-ols)
• biosupported
• 1-phenyl-3-methylpyrazol-5-one
• xanthan sulfuric acid

ACKNOWLEDGMENT

B. S. K. is grateful to the Council of Scientific and Industrial Research, New Delhi, India, for providing financial support in the form of a senior research fellowship.

Notes

^a Isolated yield.

^a Isolated yield.

^a Yields refer to pure solid products; all products were characterized by spectral data.

^a Reaction conditions: mixture of benzaldehyde (1 mmol), 5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one (2 mmol), and xanthane sulfuric acid (0.08 g) in ethanol (5 mL) was heated under reflux.

^b Yields refer to the pure, isolated, recovered catalyst.