Quinolone analogs 11: Synthesis of novel 4‐quinolone‐3‐carbohydrazide derivatives with antimalarial activity

The reaction of the 6-substituted 1-methyl-4-quinolone-3-carboxylates with hydrazine hydrate gave the 3-carbohydrazides , respectively, whose reaction with 2-, 3-, and 4-pyridinecarbaldehydes afforded the 3-(N2-pyridylmethylene)carbohydrazides and . The Curtius rearrangement of compound provided the N,N′-bis(4-quinolon-3-yl)urea presumably via the 3-carboazide 11 and then 3-isocyanate 12. Compounds , , and were found to possess antimalarial activity from the in vitro screening data. J. Heterocyclic Chem.,(2011).