The research included the preparation of two Schiff bases MA1,2 starting from1-methyl-pyrazole-4-carbaldehyde with 4-chloroaniline or 4-amino antipyrine in equal moles in the presence of glacial acetic acid. Then xazepane rings MA (3-6) were prepared from MA1,2 with phthalic anhydride or maleic anhydride. The prepared chemical formulas were confirmed using FTIR, 1HNMR, and 13CNMR spectroscopy. The toxicity activity of the compound MA2 against breast cancer MDA and REF cells was tested at seven concentrations (400, 200, 100, 50, 25, 12.5, 6.25) ml/ µg. The study also showed the lowest inhibition rate for MDA cancer line cells at 6.25 µg/ml by (4%) and the highest inhibition rate at 400 µg/ml by 77%, and the study showed the compound with the highest toxicity in healthy cells (64%-80%).