Nurhayati, Asda2021-09-232021-09-232021-01wahyu sari yenihttps://repository.unri.ac.id/handle/123456789/10206Pyrazole is an important group of five circular heterocyclic compounds containing two adjacent nitrogen atoms. Pyrazole compounds also have two endocyclic double bonds which is known to have diverse interesting biological activities such as, anticancer, antitumor and antioxidant. In this study, the pyrazole analogue 5-(3-fluorophenyl)-3- (naphthalene-2-yl)-1-phenyl-1H-pyrazole (PZL 2N-3F) was successfully synthesized through the synthesis of one-pot cyclization of pyrazoline which was then continued. By oxidative aromatization reaction of pyrazoline 5-(4-fluorophenyl)-3-(naphthalene2-yl)- 1-phenyl-4,5-dihydro-1H-pyrazole with glacial acetic acid under reflux for 42 hours. The purity of the synthesized compound was determined using the TLC, melting point and HPLC analysis. Structure identification was carried out through spectroscopic analysis of UV and FTIR. The yield obtained from the synthesis of PZL 2N-3F compound was 14.8%. The toxicity of pyrazole compounds was determined by the BSLT method using shrimp Larvae (Artemia salina Leach). The results of the BSLT for the PZL 2N-3F compound were non-toxic with an LC50 value of = 606.7 μg/mL.enBrine Shrimp Lethality TestpyrazolepyrazolinerefluxtoxicityArticle