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 mu g concentration. Some of our compounds showed excellent antimicrobial activities than control drugs. (C) 2008 Elsevier Masson SAS. All rights reserved.