SINTESIS 3-(4-KLOROFENIL)-5-[4-(DIMETILAMINO)FENIL]-2-PIRAZOLINA-1-KARBALDEHIDA DAN UJI AKTIVITASNYA SEBAGAI ANTIBAKTERI; SYNTHESIS OF 3-(4-CHLOROPHENYL)-5-[4-(DIMETHYLAMINO) PHENYL]-2-PYRAZOLINE-1-CARBALDEHYDE AND ITS ACTIVITIES TEST AS ANTIBACTERIA

Jusuf, Daniel O, Tutik Dwi Wahyuningsih

2015 | Skripsi | FMIPA

Synthesis of 2-pyrazoline-1-carbaldehyde derivative from 4-dimethylaminobenzaldehyde with 4-chloroacetophenone and test of its antibacterial activity has been carried out. First step, condensation of aryl aldehyde and aryl ketone to produce chalcone was done, then followed by cyclization of chalcone with hydrazine monohydrate and formic acid to give pyrazoline, which finally tested as an antibacterial agent. Chalcone was synthesized via Claisen Schmidt condensation from 4-dimethylaminobenzaldehyde and 4-chloroacetophenone in basic condition under stirring at room temperature for 15 minutes. Then, chalcone was reacted with hydrazine monohydrate in NaOH/ethanol solvent under reflux for 6 hours. Synthesized product was then analyzed by FTIR, GC-MS, 1H and 13C-NMR spectrometers. The pyrazoline was tested for its antibacterial activity using agar well diffusion test against Gram positive bacteria (Staphylococcus aureus, Bacillus cereus, Bacillus substilis) and Gram negative bacteria (Escherichia coli, Shigella flexneri, Salmonella thiphymurium). The result showed that, Claisen Schmidt condensation reaction yielded yellow solid chalcone in 96,14%, while white solid of pyrazoline compound has been synthesized in 91,75% yield. Antibacterial test showed that pyrazoline was active against selected Gram positive and Gram negative bacteria, with concentrations that showed the best activity for Bacillus substilis was 1000 ppm (5,8 mm).

Kata Kunci : Pyrazoline; chalcone; Claisen Schmidt; antibacterial activity