反应详情

A solution of 5,6-dichloro-2-(4-carboxy-2-methoxyphenyl)benzimidazole and 5,6-dichloro-2-(4-carboxy-2-hydroxyphenyl)benzimidazole (0.5 g, 1.48 mmol), prepared as described in Preparation 3,1-hydroxybenzotriazole (0.21 g, 1.56 mmol) and N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (0.35 g, 1.82 mmol) in THF (20 ml) was refluxed for 5 h. A solution of 1,2,2,6,6-pentamethyl-4-aminopiperidine (0.25 g, 1.5 mmol) in THF (3 ml) was added dropwise and refluxed for 3 h. After cooling to room temperature the solvent was evaporated under vacuum and the crude residue was purified by column chromatography eluting with CH2Cl2/MeOH/NH4OH 86:10:0.6 to give 10 mg of the title compound, mp>250° C.

1. temperaturewas refluxed for 5 h
2. temperaturerefluxed for 3 h
3. customwas evaporated under vacuum
4. customthe crude residue was purified by column chromatography
5. washeluting with CH2Cl2/MeOH/NH4OH 86:10:0.6