for the following products
Ethyl 1,2-dihydro-4-hydroxy-2-oxo-3-quinolinecarboxylate | Ethyl 2,4-dihydroxyquinoline-3-carboxylate | Ethyl 4-hydroxy-2-oxo-1,2-dihydroquinoline-3-carboxylate and 1,2-Dihydro-4-hydroxy-2-oxo-3-quinolinecarboxylic acid ethyl ester
