Abstract

A base catalyzed sequential one-pot protocol for an effective preparation of 3-(substitutedphenyl) -6,6-dimethyl-2-(substitutedphenylcarbonyl)-3,5,6,7-tetrahydro-1-benzofuran- 4(2H)-one derivatives have been described. One-pot reaction of aromatic aldehydes, various phenacyl bromide and dimedone gives corresponding substituted benzofurans in economically affordable yields with stereo specificity at 2^nd and 3^rd position via formation of substituted pyridinium ylides. Newly synthesized compounds were characterized by different spectral techniques such as IR, ¹H NMR, ¹³C NMR and Mass spectrometry. Furthermore, the structure of compound 4f was unambiguously assigned by X-ray crystallography. All the synthesized compounds were subjected to in-vitro antimicrobial screening against a panel of pathogenic strains of bacteria to evaluate their potency as a MIC. Some of the compounds were found to be equipotent or extra potent than commercial antibiotics against some active strains.

Keywords: Tetrahydrobenzofurans, dimedone, multicomponent reactions (MCRs), antimicrobial activity, MIC, XRD study.

Graphical Abstract