| abstract |
Preparation methods of 2-(N-substituted)-amino-benzimidazole derivatives are disclosed, compring such steps: (1) reacting 2-(N-protecting group)-benzene-1,2-diamines with N- phenoxycarbonylamines to obtain 2-(N-substituted)-amino-aryl ureas; (2) in sutable solvent, reacting 2-(N-substituted)-amino-aryl ureas with triphenyldichlorophosphorane or triphenyldibromophosphorane that is obtained by triphenyl phosphorus oxide and oxalyl chloride or diphosgene or triphosgene, or by triphenyl phosphorus oxide and bromine, and in the presence of organic base cyclization to give the compound of 1-protecting group-2-(N-substituted)-aminobenzimidazoles; (3) deprotection of 1-protecting group-2-(N-substituted)-aminobenzimidazoles to obtain 2-(N-substituted)-amino-benzimidazole. Present methods have simple operation, high yields, and reduced costs. |