Synthesis and antitumor activities of certain novel 2-amino-9-(4-halostyryl)-4H-pyrano[3,2-h]quinoline derivatives

A series of (E) 4H-pyrano[3,2-h]quinoline-3-carbonitrile (5a-f) and (E) ethyl 4H-pyrano[3,2-h]quinoline-3-carboxylate (6a-f) derivatives were synthesized by interaction of (E) 2-(4-chloro/bromo/fluorostyryl)-8-hydroxyquinoline (3a-c) with alpha-cyano-p-chloro/bromocinnamonitriles (4a,b) and ethyl alpha-cyano-p-chloro/bromocinnamates (4c,d), respectively. Structures of these compounds were established on the basis of IR, H-1 NMR, C-13 NMR, C-13 NMR-DEPT, C-13 NMR-APT, and MS data. The new compounds were evaluated for antitumor activities against three different human tumor cell lines MCF-7, HCT, and HepG-2. The results of antitumor evaluation revealed that compounds 5a,d and 6a,c,d inhibited the growth of cancer cells compared to Vinblastine. The structure-activity relationships were discussed.