Anticancer evaluation of difunctional substituted 1,2-dihydrophthalazines

Anticancer activity of a series of difunctional substituted 1,2-dihydrophthalazines has been studied within the international scientific program “NCI-60 Human Tumor Cell Lines Screen”. Screening was performed in vitro on 60 cell lines of lungs, kidneys, CNS, ovaries, prostate, and breast cancer, epithelial cancer, leukemia, and melanoma. The most effective compounds were those with an aryl substituent at N-2 of the phthalazine cycle: 4-(4-chlorophenyl)-2-(4-methylphenyl)-1,2-dihydrophthalazine (average lg GI 50 = -5.79, lg TGI = -5.42, lg LC 50 = -4.97), and 2,4-bis(4-chlorophenyl)-1,2-dihydrophthalazine (average lg GI 50 = -5.57, lg TGI = -5.08, lg LC 50 = -4.61).