反应详情

A mixture of the product from Example 218A (384.6 mg, 0.924 mmol), iron powder (317.4 mg, 5.683 mmol), and ammonium chloride (323.7 mg, 6.052 mmol) in water (3 mL) and ethanol (6 mL) was heated at 70° under a nitrogen atmosphere for 1 hour. The reaction was cooled to room temperature and vacuum filtered, washing the residue with methanol. The filtrate was concentrated under vacuum and azeotroped with toluene (50 mL). The residue was purified by silica gel flash chromatography using a gradient of 7% to 10% ethyl acetate/methylene chloride as eluent to provide the title compound as a beige solid (272 mg, 0.704 mmol, 76%).

1. temperaturewas heated at 70° under a nitrogen atmosphere for 1 hour
2. filtrationvacuum filtered
3. washwashing the residue with methanol
4. concentrationThe filtrate was concentrated under vacuum
5. customazeotroped with toluene (50 mL)
6. customThe residue was purified by silica gel flash chromatography