Quinoline alkaloids – Synthesis, molecular docking studies of atanine, 2-isopropylfuro [2,3- b ] quinolines and 3,4-dihydro-2,2-dimethyl-2 H -pyrano [2,3- b ]quinolines

A simple and efficient route to synthesis of 3-prenyl-2-quinolinones, 2-isopropyl-furo[2,3-b]quinolines and 3,4-dihydro2,2-dimethyl-2H-pyrano[2,3-b]quinolines has been developed. 3(1'-Carboxy-3-methylbut-1'-enyl)-2-quinolinones have been decarboxylated using ethanolamine followed by Prevost’s reaction with HgO/I2/AcOH and AgOAc/I2/AcOH to yield 2-isopropyl-furo[2,3-b] quinolines and which on cyclization using a few drops of conc.H2SO4 in ethanol give 3,4-dihydro2,2-dimethyl-2H-pyrano[2,3-b]quinolines. All the synthesized compounds have been structurally well characterized by spectral studies. The intermediates, 3-prenyl-2-quinolinones, were isolated and characterized. Subsequently the molecular docking studies for the first time have been carried out for all the synthesized compounds using the protein kinase Epidermal Growth Factor Receptor (EGFR) inhibitors.