反应详情

A 500 mL round bottom flask under nitrogen was charged with the product of Step 2 (7.17 g, 17.30 mmol), methanol (50 ml), and dichloromethane (50 ml). Attached an addition funnel containing trimethylsilyldiazomethane in diethyl ether (2.0M) (25.9 ml, 51.9 mmol). Cooled reaction flask in an ice bath. Added contents of addition funnel dropwise. Bubbles. HPLC/MS looks good after 0.5 hours. Quenched by dropwise addition of 2.5% potassium bisulfate. Evaporated to remove methanol. Added water. Extracted three times with ethyl acetate, dried with anhydrous magnesium sulfate, filtered and rotary evaporated filtrate. Subjected to flash column chromatography eluting with 80 hexane/20 ethyl acetate. Evaporation of fractions containing product gave the title compound as a colorless oil. (6.50 g, 15.17 mmol, 88% yield). LCMS (ES+) m/z 429.3 (M+H)+.

1. temperatureCooled
2. customreaction flask in an ice bath
3. additionAdded contents of addition funnel dropwise
4. customQuenched by dropwise addition of 2.5% potassium bisulfate
5. customEvaporated
6. customto remove methanol
7. extractionExtracted three times with ethyl acetate
8. dry with materialdried with anhydrous magnesium sulfate
9. filtrationfiltered
10. washeluting with 80 hexane/20 ethyl acetate
11. customEvaporation of fractions
12. additioncontaining product