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


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.


pyranoquinoline β-keto ester Williamson-type reaction ethyl hydroxyacetate Dieckmann condensation keto-enol tautomerism 


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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

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