 Protonation of the nitrogen forms ethyl 4-oxo-1,4-dihydroquinoline-3-carboxylate.An example is the synthesis of 4,7-dichloroquinoline.Another example is in the synthesis of antimalarials as aminoalkylamino derivatives of 2,3-dihydrofuroquinolines

The Gould reaction is also used to convert 5-aminoindole to quinolines for the purpose of synthesizing pyrazolo[4,3-"c"]pyrrolo[3,2-"f"]quinolin-3-one derivatives as modified pyrazoloquinolinone analogs.