Ulhukmi, NisaJasril, Jasril2019-04-232019-04-232019-04-23wahyu sari yenihttps://repository.unri.ac.id/handle/123456789/9660Pyrazole is five ring heterocyclic compounds with two adjacent nitrogen atoms and it have two endocyclic double bonds which is known to have diverse biological activities such as anti-inflammatory, analgesic, antibacterial, antimalarial, antioxidant, and anticancer. Pirazol analogue 5-(2-fluorofenil)-3-(naftalen-1-il)-1-fenil-1H-pirazol (PZL-2F) was synthesized via oxidative aromatization reaction of pyrazoline 5-(2-fluorofenil)-3-(naftalen-1-il)-1-fenil-4,5-dihidro-1H-pirazolin (PF CN1-2F) with glacial acetic acid. Synthesis of the pyrazole compound used the reflux at 85⁰C. The purity of the compound is determined by using TLC, melting point and HPLC analysis. The structure of the synthesized compound was confirmed by UV, FTIR, and GC-MS spectroscopic analysis. The yield of the synthesis PZL-2F compound was 57.7%. The toxicity of pyrazol was evaluated by Brine Shrimp Lethality Test (BSLT) method with shrimp larvae (Artemia salina Leach). Pyrazole PZL-2F had high toxicity with LC50 = 49,07 μg/mL.enpyrazolinepyrazolerefluxtoxicityArticle