New derivatives of pyrrolo[3,4-d]pyridazinone and their anticancer effects.

Eighteen new derivatives of pyrrolo[3,4-d]pyridazinone modified at the pyrrole and pyridazine rings were synthesized and 12 of them were evaluated in vitro through anticancer screenings. The structures of new compounds were confirmed by elemental analysis and spectral data (IR, 1H NMR). None of the eight compounds assayed blocked the cell cycle regulating CDK1/cyclin B kinase, whereas two of the six compounds tested were active in anticancer screening at the cell experiments at a concentration of > or = 10(-5) M/l.