Pyrazoline bearing benzimidazoles: Search for anticancer agent

2-acetyl benzimidazole was allowed to react with substituted aromatic aldehydes to get desired intermediate chalcones (2a–g), the cyclocondensation of these intermediates with hydrazine hydrate and phenyl hydrazine in two separate reactions yielded pyrazoline derivatives (3a–g & 4a–g respectively). Among the synthesize compounds, six compounds were granted NSC code and screened at National Cancer Institute (NCI), USA for anticancer activity at a single high dose (10−5 M) in full NCI 60 cell panel. Among the selected compounds, (4f) 2-[5-(3,4-dimethoxyphenyl)-1-phenyl-4,5-dihydro-1H-3-pyrazolyl]-1H-benzimidazole (NSC 748326) was found to be the most active candidate of the series and selected for further evaluation at five dose level screening.

Graphical abstract2-acetyl benzimidazole derived chalcones (2a–g) on cyclocondensation with hydrazine hydrate and phenyl hydrazine yielded pyrazolines (3a–g & 4a–g). Compound 2-[5-(3,4-dimethoxyphenyl)-1-phenyl-4,5-dihydro-1H-3-pyrazolyl]-1H-benzimidazole (NSC 748326) was most active candidate of the series.Figure optionsDownload full-size imageDownload as PowerPoint slide