Ethyl 4-(1-benzyl-1H-indazol-3-yl)benzoate (YD-3) was first synthesized in our laboratory as a novel anti-angiogenic agent. Recently, a series of YD-3 derivatives were synthesized, and these compounds were assayed for their cytotoxicity against HL-60 human leukemia cells. Among them, compound 4-(1-benzyl-1H-indazol-3-yl)-N-hydroxybenzamide (I) (IC50 = 2.5 mM) exhibited significant cytotoxicity against HL-60 human leukemia cells, which was superior to YD-3 (IC50 = 50.0 mM). Encouraged by this initial result, compound I was used as a lead compound, and a series of its analogs were synthesized and evaluated for their cytotoxicity of human hepatoma cell line (Hep 3B), human lung carcinoma cell line (A549), human colorectal adenocarcinoma cell line (COLO 205), human cervix adenocarcinoma cell line (HeLa), and human leukemia cell line (HL-60).?
