Synthesis of 3-(1-Ethylpiperidin-2-yl) Quinolin-2(1H)-One

Heterocycle-fused quinolinone scaffolds are important structures in drug discovery. There remain challenges for effectively synthesizing such heterocyclic compounds mainly due to the inefficient synthetic processes currently used. A simple and efficient method has been developed for the synthesis of 3-(1-ethylpiperidin-2-yl)quinolin-2(1H)-one using commercially available 2-chloroquinoline as starting material, through nucleophilic substitution, Suzuki coupling, catalytic reduction, and reductive amination reactions with a total yield of 24.5% for the final product. Theoretical analysis with density functional theory B3LYP has been conducted to gain insights into the possibility of the formation of the target product and its tautomer 3-(1-ethylpiperidine-2-yl) quinoline-2-ol.