Hidayat, Rohim2023-03-142023-03-142022-12PerpustakaanElfitrahttps://repository.unri.ac.id/handle/123456789/10900Pyrazoline is a five-ring heterocyclic compound containing two nitrogen atoms in the ring. Pyrazoline had a wide variety of biological activities, such as an inhibitor of the tyrosinase enzyme. Pyrazoline 4-(3-(4-florophenyl)-5-(2-methoxyphenyl)-4-5-dihydro- 1H-pyrazole-1-yl)benzenesulfonamide has been successfully synthesized through various stages. The first step is the formation of chalcone compounds by reacting 4- floroacetophenone and 2-methoxybenzaldehyde through the Claisen-Schmidt reaction using microwave irradiation. Then it is reacted with 4-hydrazinylbenzenesulfonamide which is synthesized through azotation and further reduction reactions, then the cyclization reaction between chalcone and 4-hydrazinylbenzensulfonamide by reflux method for 9 hours at 80°C. The structure of the synthesized compounds was confirmed by characterization using ultraviolet (UV) spectroscopy, fourier transform infra red (FTIR) and high-resolution mass spectroscopy (HRMS). The yield obtained from this pyrazoline synthesis was 93%. The toxicity of pyrazoline compounds was tested using the Brine Shrimp Lethality Test (BSLT) method using Artemia salina leach. The pyrazoline compound obtained was non-toxic with an LC50 value of 3,706 μg/mL.enBrine Shrimp Lethality Testpyrazolinetoxicity testArticle