1-Ethyl-4-hydroxy-2-oxo-1,2-dihydroquinoline-3-carboxylic acid hydrazide 3-Quinolinecarboxylic acid, 1,2-dihydro-1-ethyl-4-hydroxy-2-oxo-, hydrazide 5-22-07-00362 (Beilstein Handbook Reference) 74693-62-2 BRN 0422445