An Efficient Four-Component Synthesis of Multisubstituted Pyrano[2,3-c]pyrazole

Abstract

A series of substituted pyrano[2,3-c]pyrazole derivatives were synthesized by a one-pot reaction of methyl 4-methyl-3-oxovalerate, phenylhydrazine, aromatic aldehyde, and malononitrile in ethanol with catalysis by triethylamine. The title compounds were obtained in good to excellent yields. A possible mechanism for this reaction was proposed.

GRAPHICAL ABSTRACT

Keywords:

• Aldehyde
• malononitrile
• methyl methyl-3-oxovalerate
• multicomponent reaction
• one-pot synthesis
• pyrano[2,3-c]pyrazole

ACKNOWLEDGMENT

We thank the Natural Science Foundation of Xinjiang Science Technology Agency (No. 2009 211A02) for the financial support.

Notes

^a Yields of the isolated products.