反应详情

Tetrahydrofuran (200 ml) was added to hydrochloride (7.55 g, 31.4 mmol) of 5-amidino-2-benzofurancarboxylic acid, and the mixture was ice-cooled. The mixture was maintained at pH 10 with a 1N aqueous sodium hydroxide solution while dropwise addition of benzyloxycarbonyl chloride (6.74 ml, 47.0 mmol) over about 15 minutes. The mixture was stirred for 30 minutes and then at room temperature for 2 hours. The reaction mixture was concentrated under reduced pressure. The resulting precipitate was collected by filtration, and washed with water and an equivalent mixture of n-hexane and ethyl acetate to give 7.94 g of 5-(benzyloxycarbonylamidino)-2-benzofurancarboxylic acid as a pale-yellow solid (75%).

1. temperaturecooled
2. waitat room temperature for 2 hours
3. concentrationThe reaction mixture was concentrated under reduced pressure
4. filtrationThe resulting precipitate was collected by filtration
5. washwashed with water
6. additionan equivalent mixture of n-hexane and ethyl acetate