Parallel Synthesis of 2-Sulphanylated Bis-benzimidazoles on Soluble Polymer Support

Solid phase syntheses of S,N-substituted 2-mercaptobenzoimidazoles

2-Mercaptobenzoimidazoles are an important class of heterocycles showing biological activity in diverse therapeutic applications.

Diversity oriented synthesis of benzimidazole-based biheterocyclic molecules by combinatorial approach: a critical review

Because of the wide ranging bioactivities associated with the benzimidazole nucleus, this review highlights the advances made in the synthesis of benzimidazole-based biheterocyclic molecules by combinatorial approaches.

DNA-binding studies and antioxidant activities of two-, three- and four-coordinate silver(i) complexes containing bis(2-benzimidazolyl)aniline derivatives

Three novel structure Ag(i) complexes have been synthesized and characterized. The three ligands and Ag(i) complexes bind to DNA in an intercalation mode. The Ag(i) complexes have stronger ability of antioxidation for hydroxyl radical and superoxide radical.

Traceless synthesis of diketopiperazine fused tetrahydro-β-carbolines on soluble polymer support

The Pictet-Spengler reaction, using polyethylene glycol immobilized tryptophan ester with a variety of ketones, was achieved by refluxing condition in acidic chloroform. The linear as well as cyclic ketones were employed. All the ketones were reacted within 6-8 h to furnish soluble polymer-supported tetrahydro-β-carboline in good yields. Further expansion at N-terminus of tetrahydro-β-carbolines was achieved through a reaction with chloroacetyl chloride. Finally, the 2,5-diketopiperazine skeleton was constructed over a β-carboline by amination of the resulting N-chloroacetamides and subsequent intramolecular cyclization leading to cleavage of the polymer; constitutes a traceless synthesis of tetracyclic molecular architecture. Significantly, this strategy affords a straightforward and efficient approach for the construction of biological promising molecules with high purity and good yields.

Aqua-[1,3-bis-(benzimidazol-2-yl)-2-oxapropane]-diethano-lmanganese(II) dipicrate ethanol disolvate

In the title complex, [Mn(C₁₆H₁₄N₄O)(C₂H₅OH)₂(H₂O)](C₆H₂N₃O₇)₂·2C₂H₅OH, the Mn^II ion is in a distorted octa­hedral coordination environment, defined by an MnN₂O₄ donor set. The 1,3-bis­(benz­imid­azol-2-yl)-2-oxapropane ligand is tridentate. In the crystal structure, inter­molecular N—H⋯O and O—H⋯O hydrogen bonds link the components into a three-dimensional network. The O atoms of one of the nitro groups are disordered over two sets of sites with refined occupancies of 0.577 (11) and 0.423 (11).

Diversity-oriented synthesis of angular bis-benzimidazole derivatives under microwave irradiation

Pharmaceutically interesting, angular bis-benzimidazoles with three appendages have been synthesized successfully through a diversity-oriented approach with soluble support under microwave irradiation. Polymer immobilized o-phenylenediamine was selectively N-acylated with 2-chloro-3-nitrobenzoic acid in a primary aromatic amino moiety. The obtained amide was cyclized to benzimidazole in an acidic condition, and subsequently nucleophilic aromatic substitution with different amines was performed. Successive reduction, cyclization with various aldehydes and activated isothiocyanates yielded angular biheterocyclic benzimidazoles in good quantities. Reaction progress on polymer support was precisely monitored using the conventional proton NMR spectroscopy. Preliminary screening results showed some of these interesting compounds exhibited moderately to good inhibition against vascular endothelial growth factor receptor 3 (VEGFR-3), which is related to invasion and migration of cancer cells.