Putri, Wahyuni Eka2021-08-262021-08-262020-10wahyu sari yenihttps://repository.unri.ac.id/handle/123456789/10156Pyrazole is a 5 ring heterocyclic compound consisting of three carbon atoms and two nitrogen atoms in adjacent positions. In this study, the pyrazole analogue 5-(3-chlorophenyl)-3-(naphthalen-2-il)-1-phenyl-1H-pyrazole (PZL-2N-3Cl) was successfully synthesized from pyrazoline 5-(3-chlorophenyl)-3-(naphthalen-2-il)-1- phenyl-4,5-dihydro-1H-pyrazoline (PF-CN2-3Cl) with glacial acetic acid via oxidative aromatization reaction using reflux for 24 hours. The purity of the synthesized compound was determined using TLC and melting point. The structure of the synthesized compound was confirmed by UV and FTIR spectroscopic analysis. The yield obtained from the synthesis of the PZL-2N-3Cl compound was 30,12%. The toxicity test of pyrazole compounds was determined by the BSLT method using shrimp larvae (Artemia salina Leach). Pirazol PZL-2N-3Cl is non-toxic with an LC50 value of = 4.634,4 μg / mLenaromatizationpyrazoletoxicityArticle