反应详情

温度

23 °C

To a mixture containing the compound of Example 37(0.5 g, 1.05 mmol) in tetrahydrofuran (30 mL) and triethylamine (0.6 mL) at -10° C., is added slowly with stirring a solution of ethyl chloroformate (0.14 g, 1.29 mmol) in tetrahydrofuran (10 mL). After 30 minutes, 30% ammonium hydroxide (0.6 mL) is added and the mixture is stirred for 18 hours at 23° C. The mixture is diluted with water (100 mL) and is extracted with ethyl acetate (3×100 mL). The combined extract is washed with 2N HCl (200 mL) and brine (200 mL), dried over MgSO4 and concentrated to give crude product (0.55 g). Crystallization from acetonitrile gives pure title compound in 90% yield as a white solid, m.p. 169°-170° C.

1. additionis added slowly
2. extractionis extracted with ethyl acetate (3×100 mL)
3. extractionThe combined extract
4. washis washed with 2N HCl (200 mL) and brine (200 mL)
5. dry with materialdried over MgSO4
6. concentrationconcentrated
7. customto give crude product (0.55 g)
8. customCrystallization from acetonitrile