A new series of enaminones derived from 3-acetyl-1-aryl-4-benzoyl-5-phenyl-1 H-pyrazoles has been obtained and their reactions with hydrazine hydrate, guanidine hydrochloride, 3-amino-1,2,4-triazole, 2-aminobenzimidazole and active methylenenitriles are described. The mechanisms and regioselectivity of the studied reactions are discussed. The results of screening of the antitumor activity of the enaminones against the human breast cancer cell line MCF-7 revealed that the compounds showed less activity than that of the reference drug doxorubicin. Their activity was found to depend on the nature of the substituent group on the 1-aryl moiety. The order of activity of the series is: H > 4–Cl > 4-MeO > 4-Me > 4-NO2.