Brine Shrimp (Artemia salina) Lethality Bioassay of Some 2-(Alkyl/Aryl)-6-Phenyl-4,5-Dihydropyridazin-3(2H)-one Derivatives

A series of pyridazinone derivatives, 2-(alkyl/aryl)-6-phenyl-4,5-dihydropyridazin-3(2H)-ones (3a-h), was synthesized from 6-phenyl-4,5-dihydropyridazin-3(2H)-one (2). Compound 2 was synthesized from benzoylpropionic acid (1). The synthesized compounds were characterized on the basis of their spectral (infrared, proton nuclear magnetic resonance, carbon-13 nuclear magnetic resonance, and mass spectra) and elemental analytical data. The compounds 2 and 3a-h and potassium dichromate (as reference drug) were tested at the dose level of 10, 20, and 30 µg/mL. Compounds 3d and 3b exhibited potent brine shrimp lethality with LC₅₀values of 4.023 µg and 4.20 µg. Other compounds 3g, 3f, 3c, 3h, 2, 3a, and 3e also showed significant cytotoxic activity with LC₅₀values of 13.91, 12.58, 11.91, 11.76, 10.58, 9.76, and 7.46 µg, respectively. The present study supports that brine shrimp bioassay is a simple, reliable, and suitable method for estimation of bioactivity of synthesized compounds and provides support for their use in medicine.