Oxidative Aromatization of Hantzsch 1,4-Dihydropyridines Catalyzed by Ferric Perchlorate in Ionic Liquids with Air

Abstract

A variety of Hantzsch 1,4-dihydropyridines were oxidized to the corresponding pyridines catalyzed by a catalytic amount of ferric perchlorate. The reaction was carried out in ionic liquid at room temperature, and the products were isolated in good to excellent yields. At the same time, the catalytic system was found to be reusable.

Keywords:

• Air
• aromatization
• 1,4-dihydropyridine
• Hantzsch
• ionic liquid

ACKNOWLEDGMENTS

We are grateful for the financial support from the National Natural Science Foundation of China (No. 20706027), the Education Department of China (No. 209031), and the Education Department of Liaoning (No. 2009A430).

Notes

^a Yields were analyzed by GC.

^b Three reuses of the catalytic system.

^a Isolated yield.