Bleaching earth clay (pH 12.5): a green catalyst for rapid synthesis of pyranopyrazole derivatives via a tandem three-component reaction
作者:Rahul D. Kamble、Bhaskar S. Dawane、Omprakash S. Yemul、Amol B. Kale、Snehalkumar D. Patil
DOI:10.1007/s11164-012-0887-0
日期:2013.10
Efficient three-component synthesis of pyranopyrazole derivatives by reacting substituted aromatic aldehydes (1), (4-chlorophenyl)acetonitrile (2) and 3-methyl-1H-pyrazol-5(4H)-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.