反应详情

A mixture of 115d (500 mg, 1.3 mmol) and 30% formaldehyde (650 mg, 6.5 mmol) in methanol/acetic acid (30 mL/3 mL) was stirred at room temperature for 5 minutes, followed by the addition of NaBH3CN (120 mg, 1.9 mmol). The mixture was stirred at room temperature for 4 h. water (20 mL) was added and the resulting mixture was concentrated under reduced pressure. The residue was extracted with dichloromethane (3×30 mL). The combined organic layer was concentrated under reduced pressure and the residue was purified by silica-gel column chromatography eluting with 30:1 dichloromethane/methanol to afford 115e as a yellow solid (473 mg, 92%). MS-ESI: [M+H]+ 392.

1. additionwas added
2. concentrationthe resulting mixture was concentrated under reduced pressure
3. extractionThe residue was extracted with dichloromethane (3×30 mL)
4. concentrationThe combined organic layer was concentrated under reduced pressure
5. customthe residue was purified by silica-gel column chromatography
6. washeluting with 30:1 dichloromethane/methanol