反应详情

To a stirred suspension of Compound 2A (3 g, 6.27 mmol) in dichloromethane (30 mL) was added pyridine (2.54 mL, 31.35 mmol) followed by butyryl chloride (0.98 mL, 9.41 mmol) over 1-2 mins. The resultant solution was stirred at room temperature for 1 h 30 mins. The reaction was quenched with methanol (2 mL) and the mixture diluted with 1:1 NaHCO3 (aq)/brine (50 mL) and the layers separated. The aqueous layer was extracted with dichloromethane (10 mL) and the combined organics dried over MgSO4. After filtration, the volatiles were removed and the residue azeotroped with toluene (3×10 mL). The crude material was purified by silica chromatography eluting 8% Methanol/(1:1 ethyl acetate/dichloromethane) to provide the desired product, Compound 2B (3.26 g, 5.94 mmol, 95% yield).

1. customThe reaction was quenched with methanol (2 mL)
2. additionthe mixture diluted with 1:1 NaHCO3 (aq)/brine (50 mL)
3. customthe layers separated
4. extractionThe aqueous layer was extracted with dichloromethane (10 mL)
5. dry with materialthe combined organics dried over MgSO4
6. filtrationAfter filtration
7. customthe volatiles were removed
8. customthe residue azeotroped with toluene (3×10 mL)
9. customThe crude material was purified by silica chromatography
10. washeluting 8% Methanol/(1:1 ethyl acetate/dichloromethane)