Wybrane Metody syntezy 2-amino-1H-benzimidazolu

2-Amino-1H-benzimidazoles have attracted much attention due to their varied biological activities toward numerous diseases. 2-Amino-1H-benzimidazole core structures can be found in commercial drugs such as astemizole, mizolastine or carbendazime [1, 2]. 2-(N-substituted)-aminobenzimidazoles are widely used chemical substances in medicinal chemistry. Several compounds from this class have been used as anticancer, antihistamine and antiviral agents [3–5]. An efficient practical method for the synthesis of a diverse collection of 2-aminobenzimidazoles would be of great value for drug discovery. Several synthetic methods have been reported in the literature for the synthesis of 2-aminobenzimidazoles [11]. The synthesis of 2-aminobenzimidazole may be carried out in several ways. The most popular and economical method involves the treatment of various 2-substituted anilines with different cyclising agents to yield 2-aminobenzimidazoles. The cyclocondensation of an appropriate o-phenylenediamine with cyanogen bromide affords high yields of 2-aminobenzimidazoles [12]. Hydrogenation of o-cyanaminonitrobenzene over Raney nickel catalyst gives 2-aminobenzimidazole [34, 35]. Substituted 2-aminobenimidazoles have also been prepared by oxidation of the corresponding substituted thioureas with isothiocyanates using desulfurizing agents such as mercury-(II) oxide or methyl iodide [18–21].