反应详情

To a stirred suspension of sodium boronhydride (1.89 g, 50 mmol) and 9-xanthencarboxamide (2.25 g, 10 mmol) in dioxane (20 mL) was added acetic acid (3.0 g, 50 mmol) in dioxane (10 mL) over a period of 10 minutes at 10° C.; the reaction mixture was stirred at reflux for 2 hours. The reaction mixture was concentrated to dryness in vacuo, excess reagent was decomposed with water and the solution extracted with chloroform. The extract was washed with water and dried over anhydrous sodium sulphate. The chloroform layer was evaporated in vacuo and the residue was purified by silica gel column chromatography (ethylacetate:methanol, 9:1 as eluent) to give a white solid (1.6 g, 7.6 mmol) in 76.2% yield.

1. temperatureat reflux for 2 hours
2. concentrationThe reaction mixture was concentrated to dryness in vacuo, excess reagent
3. extractionthe solution extracted with chloroform
4. washThe extract was washed with water
5. dry with materialdried over anhydrous sodium sulphate
6. customThe chloroform layer was evaporated in vacuo
7. customthe residue was purified by silica gel column chromatography (ethylacetate:methanol, 9:1 as eluent)