Synthesis <i>N</i>-Phenyl Pyrazoline from Dibenzalacetone and Heme Polymeration Inhibitory Activity (HPIA) Assay

Abstract

The synthesis of 1,5-diphenyl-3-styryl-4,5-dihydro-1H-pyrazole (B1) and 5-(3,4-dimethoxyphenyl)-3-(3,4-dimethoxystyryl)-1-phenyl-4,5-dihydro-1H-pyrazole (B2) have been conducted from 1,5-diphenylpenta-1,4-dien-3-on (A1) and 1,5-bis(3,4-dimethoxyphenyl)penta-1,4-dien-3-one (A2). Heme polymerization inhibitory activity (HPIA) assay of the synthesized compounds has also been carried out. The first step of reaction was Claisen-Schmidt condensation of benzaldehyde derivatives and acetone using NaOH 20% and ethanol as solvent. Dibenzalacetone derivatives were reacted with phenylhydrazine using acetic acid to form N-phenylpyrazoline. The structure of products was characterized by FT-IR, GC-MS, DI-MS, 1H- and 13C-NMR The result of heme polymerization inhibitory activity assay showed that IC50 of B1 and B2 1.26 and 0.79 mM while quinine 1.26 mM. The result indicated that compound B2 was more potent as antimalarial than quinine.