Synthesis and antimicrobial evaluation of 1-(benzofuran-2-yl)-4-nitro-3-arylbutan-1-ones and 3-(benzofuran-2-yl)-4,5-dihydro-5-aryl-1-[4-(aryl)-1,3-thiazol-2-yl]-1H-pyrazoles

2-Acetylbenzofuran 1 on treatment with substituted aldehydes affords the corresponding chalcones 2a–c. Treatment of the chalcones with nitromethane under Michael addition condition furnished the corresponding Michael adducts 3a–c. Cyclocondensation of the chalcones 2a and 2b with thiosemicarbazide under basic refluxing conditions gave 3-(benzofuran-2-yl)-5-(4-aryl)-4,5-dihydropyrazole-1-carbothioamides 4a,b. The pyrazolines 7a–d were synthesized by treating 4a,b with phenacyl bromides in refluxing ethanol. All the synthesized compounds were screened for their antibacterial and antifungal activities at 100 μg concentration. Some of our compounds showed excellent antimicrobial activities than control drugs.

2-Acetylbenzofuran 1 on treatment with substituted aldehydes affords the corresponding chalcones 2a–c. Treatment of the chalcones with nitromethane under Michael addition condition furnished the corresponding Michael adducts 3a–c. Cyclization of the chalcones 2a and 2b with thiosemicarbazide under basic refluxing conditions gave 3-(benzofuran-2-yl)-5-(4-aryl)-4,5-dihydropyrazole-1-carbothioamides 4a,b. The pyrazolines 7a–d were synthesized by treating 4a,b with phenacyl bromides 5a,b in refluxing ethanol. All the synthesized compounds were screened for their antibacterial and antifungal activities. Compound 7a showed a significant activity against Escherichia coli higher than that of the control drug, whereas compound 3a showed activity against Aspergillus niger equal to that of the antifungal reference drug.Figure optionsDownload as PowerPoint slide