Synthesis of new pyrazole derivatives derived from 4-hydroxy coumarin and evaluation of their biological activity | ||
| Al-Mustansiriyah Journal of Science | ||
| Article 1, Volume 23, Issue 6, September 2012, Pages 83-92 | ||
| Author | ||
| Redha I. H.Al-Bayati | ||
| Abstract | ||
| In this work new coumarin derivatives were synthesized, from 4-hydroxy coumarin as a starting material, by its reaction with acetyl chloride, using pyridine as a base to form 3-acetyl-4-hydroxy coumarin 2. Then the reaction was followed up by the formation of schiff bases 3-7, through the treatment of 2 and hydrazine derivatives in boiling absolute ethanol. Pyrazole derivatives 8-12 were finally synthesized by ring closure reaction of schiff bases in the presence of few drops of concentrated sulfuric acid as a catalyst. The newly synthesized compounds were confirmed by FT-IR-spectra and CHN-analysis, and they showed good agreement with the proposed structures. Also the biological activity of some of the test compounds were investigated in vitro, against some bacterial and fungal microorganisms. Coumarin containing schiff bases and pyrazole derivatives: 3,4,5,7 and 9, 12 respectively, exhibited good antimicrobial activity against Gram (+) bacteria and a reasonable antibacterial activity against Gram (-) E.coli. Compound 3 demonstrated the maximum antifungal activity against C.albicans. Compound 12 was the most potent against the resistent pathogenic bacteria, Pseudomonas aeruginosa . | ||
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