反应详情

温度

0 °C

Cis-4-Hydroxy-D-proline (15 g, 115 mmol) was suspended in 150 mL anhydrous methanol under an argon atmosphere, then cooled to 0° C. before bubbling in HCl gas for 15 minutes. The solution gradually became homogenous. The argon and HCl gas lines were removed and the solution was refluxed for 4 h. The solution was cooled and then concentrated under reduced pressure. The crude material was redissolved in 100 mL methanol and diethyl ether was added until a precipitate formed. The precipitate was filtered off, washed with diethyl ether, and dried in vacuo overnight to reveal 1 (20 g, 95%) as a white solid. MS: APCI (AP+): 146 (M)+.

1. custombefore bubbling in HCl gas for 15 minutes
2. customThe argon and HCl gas lines were removed
3. temperaturethe solution was refluxed for 4 h
4. temperatureThe solution was cooled
5. concentrationconcentrated under reduced pressure
6. dissolutionThe crude material was redissolved in 100 mL methanol
7. additiondiethyl ether was added until a precipitate
8. customformed
9. filtrationThe precipitate was filtered off
10. washwashed with diethyl ether
11. customdried in vacuo overnight