(2Z)-2-(3-Hydroxybenzylidene)-N-(3-methoxyphenyl)hydrazinecarbothioamide (12, IC50 = 17.44 ± 0.01 μM) was found to be most potent compound of this series targeting HER-2 overexpressed breast cancer cells compared to the standard drug 5-fluorouracil (5-FU) (IC50 = 38.58 ± 0.04 μM). Here, ERBB2 is linked to breast cancer.