Synthesis and anti- Plasmodium falciparum evaluation of novel pyrazolopyrimidine derivatives

Nine 1-phenyl-1 H -pyrazolo[3,4- d ]pyrimidine derivatives with different substituents in the 4-position of the phenyl group and benzenesulfonamide moiety were synthesized and evaluated against Plasmodium falciparum . Six compounds exhibited activity in vitro against the chloroquine-resistant clone W2 with IC 50 values ranging from 5.13 to 12.22 µM. The most active derivative with substituents R 1 = F / R 2 = CH 3 exhibited an IC 50 value of 5.13 µM and an IS value of 62.90, which was higher than that of the control drug sulfadoxine. For this reason, it is possible to conclude that the 1 H -pyrazolo[3,4- d ]pyrimidine system is promising as a prototype for further studies of antimalarial candidates.