RESUMEN
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.