Design,Synthesis, and Pharmacological Assay of Novel Compounds Based on Pyridazine Moiety as Potential Antitumor Agents

In an endeavor to develop antitumor agents, we made a credible survey regarding synthesis, structure, and pharmacological assay of novel pyridazine derivatives, so that 2‐((6‐(4‐chloro‐3‐methylphenyl)pyridazin‐3‐yl)oxy)acetohydrazide 3 was utilized as scaffold to build novel compounds 4 – 19 by reaction with various electrophilic reagents, followed by determination and explanation atropisomerism phenomena and tauomerism ratio such as keto‐enol and lactam–lactim tautomers for some synthesized compounds. In vitro, these compounds were screened for antitumor efficacy versus two cell lines, namely, hepatocellular carcinoma and mammary gland breast cancer, by using MTT assay. Among the examined compounds, compound 16 was exhibited promising potent activity (IC₅₀ = 8.67 ± 0.7 μM) versus HepG2 cell line. Meanwhile, compounds 3 and 16 were manifested the very highest efficacy (IC₅₀ = 5.68 ± 0.6 and 9.41 ± 0.9 μM) versus MCF‐7 cell line.