Synthesis of Fused Imidazoles and Benzothiazoles from (Hetero)Aromatic ortho-Diamines or ortho-Aminothiophenol and Aldehydes Promoted by Chlorotrimethylsilane

New convenient conditions for benzimidazole and benzothiazole syntheses are described. A set of benzimidazoles, 3H-imidazo[4,5-b]pyridines, purines, xanthines and benzothiazoles was readily prepared from (hetero)aromatic ortho-diamines or ortho-aminothiophenol and aldehydes using chlorotrimethylsilane in DMF as a promoter and water-acceptor agent, followed by oxidation with air oxygen.

Ryabukhin S. V.; Plaskon A. S.; Volochnyuk D. M.; Tolmachev A. A.
Synthesis 2006, 21, 3715-3726
DOI: 10.1055/s-2006-950289