Bleaching earth clay (pH 12.5): a green catalyst for rapid synthesis of pyranopyrazole derivatives via a tandem three-component reaction

• Published in: Research on chemical intermediates Vol. 39; no. 8; pp. 3859 - 3866
• Main Authors: Kamble, Rahul D., Dawane, Bhaskar S., Yemul, Omprakash S., Kale, Amol B., Patil, Snehalkumar D.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-10-2013
• Subjects: Catalysis; Chemistry; Chemistry and Materials Science; Inorganic Chemistry; Physical Chemistry; pyrazole; Pyrano[2,3; Bleaching earth clay (pH 12.5); PEG-400; Multi-component reaction
• ISSN: 0922-6168; 1568-5675
• DOI: 10.1007/s11164-012-0887-0

Efficient three-component synthesis of pyranopyrazole derivatives by reacting substituted aromatic aldehydes (
1
), (4-chlorophenyl)acetonitrile (
2
) and 3-methyl-1
H
-pyrazol-5(4
H
)-one (
3
) using bleaching earth clay (pH 12.5) as heterogeneous catalyst and PEG-400 as green solvent is reported in the present communication. The reaction time and product yields are excellent. Catalyst and solvent recovery and reusability are very good. This is a simple, green and rapid method for synthesis of pyranopyrazole derivatives.