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.
benzimidazoles - benzothiazoles - aldehydes - chlorotrimethylsilane - parallel synthesis