2H-[1]benzopyrano[4,3-b]pyridine-3-carboxylic acid, 1-ethyl-1,5-dihydro-2,5-dioxo-, ethyl ester InChI=1/C17H15NO5/c1-3-18-14-10-7-5-6-8-13(10)23-17(21)11(14)9-12(15(18)19)16(20)22-4-2/h5-9H,3-4H2,1-2H ethyl 1-ethyl-2,5-dioxo-1,5-dihydro-2H-chromeno[4,3-b]pyridine-3-carboxylate