Novel chiral ferrocenylpyrazolo[1,5-a][1,4]diazepin-4-one derivatives--synthesis, characterization and inhibition against lung cancer cells.

A series of novel 2-ferrocenyl-7-hydroxy-5-phenethyl-5,6,7,8-tetrahydro-4H-pyrazolo[1,5-a][1,4]diazepin-4-one derivatives with optical activity (2) was synthesized in the microwave-assisted condition and characterized by means of IR, (1)H NMR and mass spectroscopy, and furthermore confirmed by X-ray analysis of a representative compound (R)-2a. Preliminary biological evaluation showed that some compounds could suppress the growth of A549, H322 and H1299 lung cancer cells. Among the tested compounds, 2b-d were more effective and might perform their action through cell cycle arrest for A549 cell. Whereas these compounds inhibited growth of H1299 and H322 cells by inducing apoptosis. The anti-tumor activities of these compounds were related to the nature of substituents in benzene moiety. In addition, the results indicated also that compounds 2b-d possessed notable cytotoxicity and selectivity for A549 vs H1299 and H322 lung cancer cells.