Synthesis of 5-benzyl-2-phenylpyrazolo[1,5-a]pyrazin-4,6(5H,7H)-dione derivatives and discovery of an apoptosis inducer for H322 lung cancer cells.

A series of substituted 5-benzyl-2-phenylpyrazolo[1,5-a]pyrazin-4,6(5H,7H)-dione derivatives was synthesized by one-step reaction of ethyl 3-phenyl-1H-pyrazole-5-carboxylate derivatives and N-arylalkyl-2-chloroacetamide. Structures of the compounds were determined by IR, (1)H NMR and mass spectroscopy. In addition, a representative single-crystal structure was characterized by using X-ray diffraction analysis. The compound 5j could selectively inhibit the growth of H322 lung cancer cells which contain a mutated p53 gene in a dose-dependent manner through inducing apoptosis of cells.