Abstract
The three-component reaction of 4-hydroxycoumarin, aldehyde, and aminopyrazole in the presence of a catalytic amount of L-proline in ethanol under reflux conditions provided the cyclized product (dihydrochromeno[4,3-b]pyrazolo[4,3-e]pyridine-6(7H)-one), whereas under similar reaction conditions, replacing aminopyrazole by 1,3-dimethyl-6-aminouracil provided the acyclic three-component product (6-amino-5-((4-hydroxy-2-oxo-2H-chromen-3-yl)methyl)-1,3-dimethylpyrimidine-2,4(1H,3H)-dione). This method is metal free and atom economical, and avoids column chromatographic purification as all the products can be purified by recrystallization.
GRAPHICAL ABSTRACT
ACKNOWLEDGMENTS
The authors are grateful to IIT Patna and SAIF Panjab University for providing analytical facilities for characterization of compounds, and to SAIF-IIT Madras for providing single-crystal x-ray crystallographic data.
SUPPLEMENTAL INFORMATION
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