Design and synthesis of fluorescent symmetric <i>bis</i>-triazolylated-1,4-dihydropyridines as potent antibreast cancer agents

<p>Herein, we report the synthesis of fluorescent 1,4-dihydropyridine-linked <i>bis</i>-triazoles (<b>2a</b>–<b>2n</b>) through Hantzsch synthesis by the condensation of <i>o/m</i>-chloro-substituted benzaldehyde, ethyl 3-oxo-4(prop-2-yn-1-yloxy)butanoate, and ammonium acetate in the presence of Ba(NO<sub>3</sub>)<sub>2</sub> as a catalyst followed by the click reaction of resultant Hantzsch product (<b>1</b>) with various aromatic as well as aliphatic azides. All the synthesized compounds were well characterized by <sup>1</sup>H-NMR, <sup>13</sup>C-NMR, FTIR, and HRMS spectral techniques. Antibreast cancer evaluation of all the synthesized derivatives revealed that the compounds <b>2f</b> (IC<sub>50</sub> = 7 ± 0.02 µM) and <b>2g</b> (IC<sub>50</sub> = 5 ± 0.03 µM) showed better anticancer activity (lower IC<sub>50</sub>) than the standard drug tamoxifen (IC<sub>50</sub> = 11.2 ± 0.01 µM) against breast carcinoma (MDA-MB-231) cell line. The synthesized compounds were also screened against normal human embryonic kidney (HEK-293) cell line and found to be nontoxic. The fluorescent nature and cytotoxicity assay of these newly synthesized hybrids recommend their utility in tumor cell imaging.</p>