The synthesis, biological evaluation, and molecular modeling of new 4-hydroxy-2-oxo-1, 2- dihydroquinoline-3-carboxamides (4), 4-hydroxy-2-oxo-1, 2-dihydroquinoline-3- carbohydrazide (6), and some hexahydropyrimido [5, 4-c] quinoline-2, 5-diones (9) produced earlier by our laboratory, as AChE/BuChE inhibitors, is described. From these analyses compound 4c resulted equipotent regarding the inhibition of cholinesterases'; ...