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 min a solution of the product of Step 1 (40.0 g, 0.174 mol) in tetrahydrofuran (100 ml) was added dropwise and the reaction allowed to warm to room temperature over 3 hours. The solution was then cooled in ice, saturated ammonium chloride solution added and the aqueous mixture extracted with ethyl acetate. The combined organic extracts were then washed with brine, dried over anhydrous magnesium sulphate, 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 then cooled in ice
3. extractionthe aqueous mixture extracted with ethyl acetate
4. washThe combined organic extracts were then washed with brine
5. dry with materialdried over anhydrous magnesium sulphate
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