Synthesis of <i>N</i>-Phenylpyrazoline Derivative from 4-Chlorobenzaldehyde and 4-Chloroacetophenone and its Activity as an Antimalarial Agent

This study was aimed to synthesize N -phenylpyrazoline derivative and evaluate its antimalarial activity. The pyrazoline was synthesized from chalcone derivative through a cyclo- condensation reaction. Moreover, chalcone derivative was prepared from 4-chlorobenzaldehyde and 4-chloroacetophenone through Claisen-Schmidt condensation. The structure elucidation of the products was performed by FTIR, GC-MS, 1 H- and 13 C-NMR spectrometers. The antimalarial assay was conducted by inhibition of heme polymerization. The chalcone was obtained as a white solid in 83% yield, while N -phenylpyrazoline derivative was obtained as brown solid in 70% yield. The IC 50 values of chalcone and N -phenylpyrazoline derivatives as well as a positive control (chloroquine diphosphate) were 98.66, 20.83, and 3.54 mg/mL, respectively. The results showed that both chalcone and N -phenylpyrazoline derivatives had lower antimalarial activity than the positive control. Molecular docking studies were also performed to explain the mode of action of chalcone and N -phenyl pyrazoline as antimalarial agent.