Chemical Papers

, Volume 67, Issue 4, pp 437–443

Synthesis and keto-enol tautomerism of ethyl 4-oxo-3,4-dihydro-1H-pyrano[3,4-b]quinoline-3-carboxylate

Original Paper

DOI: 10.2478/s11696-012-0276-6

Cite this article as:
Chang, MQ., Gao, F., Li, Y. et al. Chem. Pap. (2013) 67: 437. doi:10.2478/s11696-012-0276-6


An efficient method has been developed for the synthesis of a novel β-keto ester-containing pyranoquinoline compound, i.e., ethyl 4-oxo-3,4-dihydro-1H-pyrano[3,4-b]quinoline-3-carboxylate. The method entails a two-step synthesis. The first step involves the Williamson-type reaction of ethyl 2-bromomethyl-3-quinoline-3-carboxylate with ethyl hydroxyacetate in anhydrous benzene to afford the intermediate ethyl 2-[(2-ethoxy-2-oxoethoxy)methyl]quinoline-3-carboxylate. The second step includes the Dieckmann condensation reaction of the resulting intermediate in the presence of sodium ethoxide in anhydrous toluene to afford the desired pyranoquinoline containing β-keto ester moiety. Keto-enol tautomerism of the compound thus obtained was investigated by spectroscopic methods.


pyranoquinolineβ-keto esterWilliamson-type reactionethyl hydroxyacetateDieckmann condensationketo-enol tautomerism

Copyright information

© Institute of Chemistry, Slovak Academy of Sciences 2012

Authors and Affiliations

  • Ming-Qin Chang
    • 1
  • Feng Gao
    • 1
  • Yang Li
    • 1
  • Wen-Tao Gao
    • 1
  1. 1.Institute of Superfine ChemicalsBohai UniversityJinzhouChina