反应详情

4-Picoline (16.9 ml, 0.174 mol) was added dropwise to a stirred solution of lithium di-isopropylamide (110 ml, 0.22 mol, 2M solution in heptane, ethylbenzene, tetrahydrofuran) in dry tetrahydrofuran (150 ml) at −78° C. After stirring at −78° C. for 15 minutes a solution of the product of Step 1 (40.0 g, 0.174 mol) in tetrahydrofuran (100 ml) was added dropwise. The reaction was allowed to warm to room temperature over 3 hours. The solution was cooled in ice and saturated ammonium chloride solution was added. The aqueous mixture was extracted with ethyl acetate, washed with brine, dried (MgSO4), filtered and concentrated at reduced pressure. The resulting gum was triturated with cold diethyl ether/hexane (1:1, 300 ml) and the solid collected to give the title compound, as a pale yellow solid (29 g, 64%); MS(ES+) m/e 262/264 [M+H]+.

1. additionwas added dropwise
2. temperatureThe solution was cooled in ice
3. extractionThe aqueous mixture was extracted with ethyl acetate
4. washwashed with brine
5. dry with materialdried (MgSO4)
6. filtrationfiltered
7. concentrationconcentrated at reduced pressure
8. customThe resulting gum was triturated with cold diethyl ether/hexane (1:1, 300 ml)
9. customthe solid collected