反应详情

In 200 ml of pyridine was placed 19.56 g (0.1 mol) of (2S,4R)-4-hydroxyproline ethyl ester hydrochloride, and 12.03 g (0.105 mol) of methanesulfonyl chloride was slowly added dropwise to the mixture under agitation and ice-cooling. After stirring the mixture under ice-cooling for 6 hours, the mixture was further stirred overnight at room temperature. After distilling off the pyridine under reduced pressure, 10% hydrochloric acid was added to the reaction mixture under ice-cooling. The mixture was extracted three times with 200 ml of ethyl acetate in each case and the ethyl acetate extracts were combined, washed with 40 ml of a saturated aqueous solution of sodium chloride and then dried over magnesium sulfate. The extract was concentrated under reduced pressure and dried until dryness whereby a solid substance having a melting point of 111°-113° C. was obtained in a yield of 18.7 g (78.9%) which, after recrystallization from ethyl acetate, showed a melting point of 118°-120° C.

1. additionwas slowly added dropwise to the mixture under agitation and ice-
2. temperaturecooling
3. temperaturecooling for 6 hours
4. stirringthe mixture was further stirred overnight at room temperature
5. distillationAfter distilling off the pyridine under reduced pressure, 10% hydrochloric acid
6. additionwas added to the reaction mixture under ice-
7. temperaturecooling
8. extractionThe mixture was extracted three times with 200 ml of ethyl acetate in each case
9. washwashed with 40 ml of a saturated aqueous solution of sodium chloride
10. dry with materialdried over magnesium sulfate
11. concentrationThe extract was concentrated under reduced pressure
12. customdried until dryness whereby a solid substance
13. customwas obtained in a yield of 18.7 g (78.9%) which
14. customafter recrystallization from ethyl acetate