反应详情

A solution containing the compound of Example 50, (2.5 g, 5.31 mmol), methanol (200 mL), tetrahydrofuran (200 mL) and 1N sodium hydroxide (9.5 mL) is refluxed for 3 hours. Upon cooling, the mixture is concentrated under reduced pressure, diluted with water (200 mL) and acidified with 2 N HCl. After stirring for 30 minutes, the product is filtered and recrystallized from acetonitrile to give the title compound as a white solid in 85% yield, m.p. 186°-188° C.

1. temperatureis refluxed for 3 hours
2. temperatureUpon cooling
3. concentrationthe mixture is concentrated under reduced pressure
4. additiondiluted with water (200 mL)
5. filtrationthe product is filtered
6. customrecrystallized from acetonitrile