反应详情

温度

-78 °C

A solution of the product from Example 10B (0.942 g, 5.0 mmol) in anhydrous tetrahydrofuran (50 mL) was cooled to −78° C. under a nitrogen atmosphere. To this solution was added slowly dropwise a solution of lithium diisopropylamide (3.0 mL of a 2.0 M solution in toluene/hexane/heptane, 6.0 mmol, 1.2 eq). After the addition was complete the reaction mixture was stirred at −78° C. for 1 h, and then methyl iodide (1.42 g, 10.0 mmol, 2.0 eq) was added dropwise. The reaction mixture was stirred for an additional 1.5 h at −78° C., during which time all solids dissolved. The reaction flask was then removed from the cooling bath and saturated aqueous ammonium chloride (25 mL) and water (25 mL) was added. The reaction mixture was extracted with ethyl acetate (3×100 mL) and the combined organic layers were washed with brine, dried over anhydrous magnesium sulfate, filtered, and evaporated under vacuum. The residue was purified by chromatography on silica gel, eluting with a 3/2 hexane:ethyl acetate to provide the title compound (0.87 g, 86% yield).

1. additionAfter the addition
2. stirringThe reaction mixture was stirred for an additional 1.5 h at −78° C., during which time all solids
3. dissolutiondissolved
4. customThe reaction flask was then removed from the cooling bath and saturated aqueous ammonium chloride (25 mL) and water (25 mL)
5. additionwas added
6. extractionThe reaction mixture was extracted with ethyl acetate (3×100 mL)
7. washthe combined organic layers were washed with brine
8. dry with materialdried over anhydrous magnesium sulfate
9. filtrationfiltered
10. customevaporated under vacuum
11. customThe residue was purified by chromatography on silica gel
12. washeluting with a 3/2 hexane