反应详情

温度

0 °C

At −78° C., 22.1 ml of n-butyllithium (35.4 mmol, 1.6M in hexane) were slowly added dropwise to a solution of 4.91 ml (35.0 mmol) of diisopropylamine in 45 ml of tetrahydrofuran, and the mixture was stirred at −78° C. for another 10 min and at 0° C. for another 25 min. Subsequently, at −78° C., a solution of 5.00 g (34.7 mmol) of methyl tetrahydro-2H-pyran-4-carboxylate in 45 ml of tetrahydrofuran was added, and the mixture was stirred at −78° C. for another 15 min and at 0° C. for another 30 min. At −78° C., 2.16 ml (34.7 mmol) of methyl iodide were added dropwise, and the reaction mixture was slowly warmed to −25° C. and then to room temperature overnight. The reaction was terminated by addition of 80 ml of 0.1N hydrochloric acid, and the phases were separated. The aqueous phase was extracted twice with ethyl acetate, the combined organic phases were dried over magnesium sulphate and filtered and the solvent was removed under reduced pressure. The resulting suspension was triturated with 20 ml of methyl tert-butyl ether, the precipitate was filtered off with suction and the mother liquor was concentrated under reduced pressure, giving the title compound. Yield: 5.88 g (purity 95%, quant.)

1. stirringthe mixture was stirred at −78° C. for another 15 min and at 0° C. for another 30 min
2. temperaturethe reaction mixture was slowly warmed to −25° C.
3. customto room temperature
4. customovernight
5. customThe reaction was terminated by addition of 80 ml of 0.1N hydrochloric acid
6. customthe phases were separated
7. extractionThe aqueous phase was extracted twice with ethyl acetate
8. dry with materialthe combined organic phases were dried over magnesium sulphate
9. filtrationfiltered
10. customthe solvent was removed under reduced pressure
11. customThe resulting suspension was triturated with 20 ml of methyl tert-butyl ether
12. filtrationthe precipitate was filtered off with suction
13. concentrationthe mother liquor was concentrated under reduced pressure