Abstract
For the discovery of new antibiotic drugs to face the problem of microbial resistance, a series of fused pyrazoles such as pyrazolopyrimidines 15a-f, pyrazoloquinazolines 18a, b and pyrazolotriazines 20a, b was synthesized via the reaction of 5-aminopyrazoles 8a, b with 3-(dimethylamino)-1-aryl-prop-2-en-1-ones 9a-d, 2-((dimethylamino)methylene)-5,5-dimethylcyclohexane-1,3-dione (16) and sodium nitrite (NaNO2), respectively. Finally, Schiff bases 22a-g were obtained by the condensation of 8a, b with aromatic aldehydes 21a-d. The chemical structure of the new compounds was confirmed by spectroscopy. The structure of 15b was confirmed by X-ray crystallography analysis. All compounds were screened for antibacterial properties toward multi-drug resistant bacteria (MDRB).
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