Microwave-assisted synthesis, crystal structure of pyrazolo[1,5-a]pyrazin-4(5H)-ones and their selective effects on lung cancer cells.

A series of novel pyrazolo[1,5-a]pyrazin-4(5H)-one derivatives with hydrophilic group was synthesized under general heating condition and microwave-assisted condition. The structures of compounds were determined by IR, 1H NMR and HRMS, moreover, representative crystal structures were characterized by using X-ray diffraction analysis. Preliminary biological evaluation showed that some compounds could inhibit the growth of A549, H322 and H1299 cells in dosage dependent manners. The compounds could inhibit growth of A549, H322 and H1299 cells in different mechanism. Compounds 3e-h inhibited growth of A549 cells by inducing a strong G1-phase arrest. Whereas these compounds inhibited growth of H1299 and H322 cells by inducing apoptosis.