Synthesis of new cis-fused tetrahydrochromeno[4,3-b]quinolines and their antiproliferative activity studies against MDA-MB-231 and MCF-7 breast cancer cell lines

New cis-fused tetrahydrochromeno[4,3-b]quinolines were synthesized by intramolecular [4+2] imino-Diels-Alder reactions of 2-azadienes derived in situ from aromatic amines and 7-O-prenyl derivatives of 8-formyl-2,3-disubstituted chromenones. The structures were established by spectroscopic data and further confirmed by X-ray diffraction analysis. These compounds were evaluated for their antiproliferative activity against MDA-MB-231 and MCF-7 breast cancer cells.