Sarah, Syarifah SitiZamri, Adel2018-03-072018-03-072018-03-07wahyu sari yenihttps://repository.unri.ac.id/xmlui/handle/123456789/9280Pyrazoline is five ring heterocyclic compounds with two adjacent nitrogen atoms which is known to have diverse biological activities such as antitoxicity, anticancer, antioxidant, antimalarial, antibacterial and antituberculosis. Pyrazoline analogue 3-(4-chlorophenyl)-5-(2-methoxyphenyl)-1-phenyl-4,5-dihydro-pyrazole (PF-4Cl-2OMe) was synthesized by microwave irradiation method using one-pot reaction involving condensation and cyclization reaction of 2-methoxybenzaldehyde, 4-chloroacetophenon and phenylhydrazine. Purity of the PF-4Cl-2OMe compound was checked on TLC test, determination of melting point and HPLC analysis. Pyrazoline compound have been characterized using UV, FTIR, and NMR spectrometers. The yield obtained from the synthesis of PF-4Cl-2OMe compound was 44.85%.The toxicity of pyrazoline were evaluated by Brine Shrimp Lethality Test (BSLT) method. Pyrazoline PF-4Cl-2OMe compound showed non-toxic activity with LC50 = 572.79 μg/mL.enBrine Shrimp LethalityTestmicrowavepyrazolinetoxicityArticle