Abstract
A novel series of 3-(4-fluorophenyl)-4,5-dihydro-5-(3,4,5-trimethoxy/4-nitro phenyl)-N-(substituted-phenyl)pyrazole-1-carboxamide analogues 4a-n was synthesized in two steps from 4-fluoroace-tophenone. The pyrazoline analogues were evaluated for cytotoxicity against two breast cancer cell lines (MCF-7 and MBA-MD-231) by the sulforhodamine B (SRB) assay. N-(4-Chlorophenyl)-3-(4-fluorophenyl)5-(4-nitrophenyl)-4,5-dihydro-1H-pyrazole-1-carboxamide (4b) showed the most promising cytotoxicity among the series, with GI(50) <0.1 and 45.8 mu M against the cancer cell lines, MCF-7 and MDA-MB-231, respectively. The anticancer activity of 4b was found to be comparable to that of the standard drug adriamycin (GI(50) < 0.1) against the MCF-7 cancer cell line. Structure activity relationships (SAR) are also considered.