反应详情

A mixture of 239b (469 mg, 1.4 mmol), 37% aqueous formaldehyde (4.0 g, 50 mmol), NaBH3CN (261 mg, 4.2 mmol), and 1M zinc chloride in ethoxyethane (4 mL, 4.2 mmol) in methanol (40 mL) was stirred at room temperature for 2 hours. The mixture was added to water (20 mL) and concentrated under reduced pressure. The residue was extracted with dichloromethane (3×50 mL). The combined organic layer was concentrated under reduced pressure and the residue was purified by silica-gel column chromatography eluting with 10:1 methylene chloride/methanol to afford 239c as a yellow solid (300 mg, 83%). MS-ESI: [M+H]+ 349.

1. concentrationconcentrated under reduced pressure
2. extractionThe residue was extracted with dichloromethane (3×50 mL)
3. concentrationThe combined organic layer was concentrated under reduced pressure
4. customthe residue was purified by silica-gel column chromatography
5. washeluting with 10:1 methylene chloride/methanol