Chinese Journal of Catalysis ›› 2014, Vol. 35 ›› Issue (7): 1036-1042.DOI: 10.1016/S1872-2067(14)60038-3

• Articles • Previous Articles     Next Articles

Four-component one-pot synthesis of unsymmetrical polyhydroquinoline derivatives using 3-methyl-1-sulfonic acid imidazolium hydrogen sulfate as a catalyst

Nader Ghaffari Khaligha,b   

  1. a. Department of Chemistry, Qaemshahr Branch, Islamic Azad University, Qaemshahr, 47651-61964, Iran;
    b. Research House of Professor Reza, Education Guilan, District 1, Rasht, 41569-17139, Iran
  • Received:2013-12-12 Revised:2014-01-15 Online:2014-06-28 Published:2014-06-28

Abstract:

3-Methyl-1-sulfonic acid imidazolium hydrogen sulfate has been used as an efficient, halogen-free, and reusable Brönsted acidic ionic liquid catalyst for the synthesis of ethyl-4-aryl/heteryl-hexahydro-trimehtyl-5-oxoquinoline-3-carboxylates via the one-pot condensation of dimedone with aryl/heteryl aldehydes, ethyl acetoacetate, and ammonium acetate under solvent-free conditions. This method has the advantage of being clean and simple, as well as providing the desired product in high yield over a short reaction time. Furthermore, the catalyst could be recycled and reused four times without any discernible reduction in activity.

Key words: Unsymmetrical polyhydroquinoline, Brönsted acidic ionic liquid catalyst, Multicomponent reaction, Solvent-free condition