A method for selective N-protection of hydroxyalkylbenzimidazoles using 2, 2, 2- trichloroethylchloroformate (Troc-Cl) applicable to various alkyl chain lengths has been developed. In the specific case of 5-(1-[2, 2, 2-trichloroethyl formyl]-benzimidazol-2-yl)- propan-1-ol, migration of Troc from the benzimidazole to the primary alcohol occurs in the presence of triethylamine, allowing the choice of selective N-Troc or O-Troc protection.
