The introduction of a basic residue, that is an amino alkyl residue, into the amino group of a heterocyclic ring system produces a compd. which has an action upon the agent causing malaria in birds. To test the activity of the compds. prepared, canaries were injected intramusc. with blood containing the malaria parasites, and the substances to be tested administered by stomach tube on the day of infection and on the following 5 days. In untreated birds, the plasmodia appear in the blood 4 or 5 days after infection, while the compds. active against malaria delay the appearance in the blood 10 days or more. The chemotherapeutic index of a compd. is the ratio of the smallest active dose to the tolerated dose. Of the compds. prepared and tested, 8-methoxy-6(diethylamino-[delta]-pentyl)-aminoquinoline, 6-methoxy-4(diethylanaino-[delta]-pentyl)-aminoquinoline, 5,6-di-methoxy-8(diethylamino-[delta]-pentyl)-aminoquinoline, 6-hy-droxy-8(dimethylamino-[gamma]-butyl)-aminoqumoline and 6-acetoxy-8(dimethylamino-[gamma]-butyl)-aminoquinoline were active against malaria, while 5,6,7-trimethoxy-8(diethylamino-[delta]-pentyl)-aminoquinaldine, 6-hydroxy-8(dimethylamino-[gamma]-butyl)-acetylaminoquinoline, 5,7-dimethoxy-8 (diethylamino-[delta]-pentyl)-aminoquinoline, 7-methoxy-8(dimethylamino-[beta],[beta]-dimethylpropyl)-aminoquinoline and formylatebrin had no activity. The activity against malaria of the quinoline compds. basically alkylated in the 4, 6 and 8 positions depends upon whether a system of quinoid bonds may be formed between the amino group on the quinoline ring and the ring N.