Synthesis and Biological Evaluation of 5′-Arylspiro[piperidine-4,3′-pyrrolo-[2,3-b]pyridin] Analogues

Spirooxindole motifs found in many natural products and biologically active molecules have become important skeletons given their promising therapeutic activities. In this study, we describe the synthesis of a novel series of spiro[piperidine-4,3 '-pyrrolo[2,3-b]pyridin]-2 '(1 ' h)-one analogues and present the in vitro antiproliferative activity of these compounds against four human cancer cell lines. Synthesis of analogues was done using a rational designing approach in a seven-step sequence, and the characterization of compounds was performed using H-1-NMR, LC-MS, and C-13-NMR. Thirteen novel compounds were synthesized in moderate to good yields. The anti-proliferation activity of the compounds against human breast MCF-7 and MDA-MB-231, leukemic K-562, and lung A549 cancer cells was determined by a standard 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay. Two compounds among all the synthesized compounds had moderate IC50 values in MCF-7 cells and thus were identified to have better antiproliferative activity against estrogen-receptor-positive cancer cells.