反应详情

The 5-(5-benzoylbenzimidazole-2-yl)-2,4-dimethylpyrrole-3-carboxylic acid ethyl ester (200 mg) obtained in Example 53 (2) was dissolved in ethanol (5 ml) and tetrahydrofuran (5 ml). To this solution was added a 4 N sodium hydroxide aqueous solution (10 ml), and the mixture was heated under reflux for 12 hours. After the starting material was disappeared, the reaction mixture was allowed to cool to room temperature, and neutralized with a 1 N hydrochloric acid solution. The precipitate was collected by filtration to afford 5-(5-benzoylbenzimidazol-2-yl)-2,4-dimethylpyrrole-3-carboxylic acid (139 mg, 75%) as a light yellow solid.

1. temperaturethe mixture was heated
2. temperatureunder reflux for 12 hours
3. filtrationThe precipitate was collected by filtration