Tổng hợp và thử hoạt tính kháng khuẩn của một số dẫn chất 2-pyrazoIin

Abstract

From 5-bromosalicylaldehyde and some acetophenone derivatives, 5 chalcones were synthesized. Further; 2-pyrazoHne derivatives were synthesized by condensation of the obtained chalcones with hydrazine derivatives. All the 20 synthesized compounds, including 5 chalcones and 15 2-pyrazoline derivatives, were characterized by NMR and MS and evaluated for the bactericidal activities against E. coli ATCC 25922 and S. aureus ATCC 25923. The derivatives of HP6-HP10 (1 -phenyi-2-pyrazoHne derivatives) had a low value of MIC (4-8 pg/ml) on S. aureus. Structure-activity relationships revealed R2 substituent at 1-position of 2-pyrazoHn moiety to be of essential importance for antibacterial activity (R2 of phenyl is better than R2 of hydrogen or acetyl). Besides, haiogenated R1 of the aromatic ring at 3-position of 2-pyrazotin moiety seemed significantly influential on diminution of MIC value.