反应详情

(2S,4R)-4-Hydroxy-pyrrolidine-2-carboxylic acid dimethylamide hydrochloride (0.39 g, 2.0 mmol) was added to a solution of the intermediate from Step B in a mixture of dichloromethane (4 ml), THF (1 ml) and DIPEA (1 ml). The reaction mixture was stirred at room temperature for 18 h. After addition of water, the mixture was extracted four times with ethyl acetate. The combined organic phase was dried over magnesium sulfate, filtered and concentrated under reduced pressure. Purification by chromatography (silica gel, 7% MeOH in dichloromethane) resulted in 0.45 g of the mixture of diastereomers (ratio about 2:1).

1. extractionthe mixture was extracted four times with ethyl acetate
2. dry with materialThe combined organic phase was dried over magnesium sulfate
3. filtrationfiltered
4. concentrationconcentrated under reduced pressure
5. customPurification by chromatography (silica gel, 7% MeOH in dichloromethane)