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A series of some novel 2-(substituted biphenyl) benzimidazoles and their N-substituted derivatives were synthesized via microwave-mediated Suzuki-Miyaura coupling of 2-(4-iodophenyl)-1H-benzimidazole or 2-(4-iodophenyl)-6-amino-1H-benzimidazole and arylboronic acids. The method reported herein offers advantageous shorter reaction times, higher yields and is applicable to a large set of substrates. All the synthesized compounds were screened for their antibacterial activity against Staphylococcus aureus and Salmonella typhimurium bacterial species. J. Heterocyclic Chem., (2011).

Herein, we present an innovative, novel, and highly convenient protocol for the synthesis of 3-(pyridin-2-yl)-5-sec-aminobiphenyl-4-carbonitriles (6a, 6b, 6c, 6d, 6e, 6f, 6g) and 9,10-dihydro-3-(pyridine-2-yl)-1-sec-aminophenanthrene-2-carbonitriles (10a, 10b, 10c, 10d, 10e), which have been delineated from the reaction of 4-sec-amino-2-oxo-6-aryl-2H-pyran-3-carbonitrile (4a, 4b, 4c, 4d, 4e, 4f, 4g) and 4-sec-amino-2-oxo-5,6-dihydro-2H-benzo[h]chromene-3-carbonitriles (9a, 9b, 9c, 9d, 9e) with 2-acetylpyridine (5) through the ring transformation reaction by using KOH/DMF system at RT. The salient feature of this procedure is to provide a transition metal-free route for the synthesis of asymmetrical 1,3-teraryls like 3-(pyridin-2-yl)-5-sec-aminobiphenyl-4-carbonitriles (6a, 6b, 6c, 6d, 6e, 6f, 6g) and 9,10-dihydro-3-(pyridine-2-yl)-1-sec-aminophenanthrene-2-carbonitriles (10a, 10b, 10c, 10d, 10e). The novelty of the reaction lies in the creation of an aromatic ring from 2H-pyran-2-ones and 2H-benzo[h]chromene-3-carbonitriles via two-carbon insertion from 2-acetylpyridine (5) used as a source of carbanion.

The title compounds (V) and (VIII) display good antibacterial activity against S.aureus but they are less active against S.