Search for new pharmacophores for antimalarial activity. Part II: synthesis and antimalarial activity of new 6-ureido-4-anilinoquinazolines.

Synthesis of new 6-ureido-4-anilinoquinazolines have been accomplished and their in vitro antimalarial activity against chloroquine-sensitive P. falciparum have been examined. Out of 64 compounds evaluated, the IC(50) of 16 compounds which have displayed MIC of 0.25 microg/mL were also recorded. One of the compounds (24 g) had IC(50) value of 2.27 ng/mL which was equipotent to the standard drug chloroquine used in the bioassay. The in vivo evaluation of a few compounds among the series led to discovery of one analog (30 g) displaying 40% curative activity (28 days) against mdr P. yoeillinigeriensis at an oral dose of 100 mg/kg x 4 days.