SINTESIS TURUNAN N-ASETILPIRAZOLINA DAN UJI ANTIBAKTERI DENGAN BAHAN DASAR 3-NITROBENZALDEHIDA, 4-HIDROKSIASETOFENON DAN HIDRAZIN HIDRAT; SYNTHESIS AND ANTIBACTERY ASSAY OF NOVEL N-ACETYLPYRAZOLINE DERIVATIVE COMPOUND 3-NITROBENZALDEHYDE, 4-HYDROXYACETOPHENONE AND HYDRAZINE HYDRATE

Putri, Daratu Eviana Kusuma, Tutik Dwi Wahyuningsih

2015 | Skripsi | FMIPA UGM

A pyrazoline derivative has been synthesized from a synthesized chalcone derivative and hydrazine hydrate by cyclocondensation reaction. This research was held suppose to create a new antibacterial agent that replaces of the past resistance antibacterial agents. m-Nitrobenzaldehyde, as the first synthesis, synthesized by nitration reaction to benzaldehyde by nitric acid as a nitration agent. The nitration product was recrystallized by MTBE solvent for replacing the high toxicity of benzene. 1-(4-hydroxyphenyl)-3-(3-nitrophenyl)prop-2-en-1-one (chalcone 1) was synthesized from Claisen-Schmidt condensing m-nitrobenzaldehyde and 4-hydroxyacethophenone at room temperature in alkaline condition for 24 hours. This reaction afforded chalcone 1 in 63.6% yields. On the other hand 1-[3-(4-hydroxyphenyl)-5-(3-nitrophenyl)-4,5-dihydro-1H-pyrazol-1-yl]ethanone (pyrazoline 1) was synthesized from chalcone 1 by cyclocondensation reaction with hydrazine hydrate in glacial acetic acid on reflux condition for six hours afforded pyrazoline 1 in 45% yields. Antibacterial assay of pyrazoline 1 has been studied to againt five organisms: Bacillus cereus, Bacillus subtilis, and Staphylococcus aureus as examples of Gram-positive bacteria, Escherichia coli and Shigella flexneri as examples of Gram-negative bacteria. Antibacterial assay was held using agar well diffusion method. The assay showed that pyrazoline 1 gave the best activity to Bacillus subtilis.

Kata Kunci : m-nitrobenzaldehyde; chalcone; pyrazoline; antibacterial.