反应详情

温度

20 °C

(S)-Propyl 2-amino-3-hydroxypropanoate HCl salt (18.2 g, 99.1 mmol) was suspended in toluene (96 mL) and then thionyl chloride (8.20 mL, 13.3 g, 112 mmol) was added via an addition funnel during 15 min. The homogeneous reaction was stirred at 20° C. for 2 h. Then, the temperature was raised to 60° C. during 45 min and the reaction was maintained at that temperature for 45 min. Then, acetyl chloride (15.1 mL, 16.7 g, 213 mmol) was added via an addition funnel during a period of 2 h while the temperature reached 80° C. and the reaction was further stirred at that temperature for 30 min. The reaction was allowed to cool to 5° C. while a precipitate formed. The precipitate was collected on a fritted funnel under suction and washed with petroleum benzene (3×25 mL). The cake was dried under vacuum overnight to a final weight of 9.19 g. The mother liquor was seeded with some crystals of the cake and further diluted with petroleum benzene (25 mL) and stirred overnight at 20° C. The ensuing suspension was cooled to 5° C. and the product was collected on a fritted funnel under suction and washed with petroleum benzene (3×25 mL). The cake was dried under vacuum overnight to a final weight of 6.48 g. Combined weight (two cakes) 15.7 g, approx. 76% yield. 1H NMR: (CDCl3, 300 MHz): δ 6.40 (br s, 1H), 4.99 (dt, 1H), 4.27-4.11 (m, 2H), 3.95 (dq, 2H), 2.09 (s, 3H), 1.77-1.65 (m, 2H), 0.97 (t, 3H).

1. customThe homogeneous reaction
2. temperatureThen, the temperature was raised to 60° C. during 45 min
3. temperaturethe reaction was maintained at that temperature for 45 min
4. customreached 80° C.
5. stirringthe reaction was further stirred at that temperature for 30 min
6. temperatureto cool to 5° C. while a precipitate
7. customformed
8. customThe precipitate was collected on a fritted funnel under suction
9. washwashed with petroleum benzene (3×25 mL)
10. customThe cake was dried under vacuum overnight to a final weight of 9.19 g
11. additionfurther diluted with petroleum benzene (25 mL)
12. stirringstirred overnight at 20° C
13. temperatureThe ensuing suspension was cooled to 5° C.
14. customthe product was collected on a fritted funnel under suction
15. washwashed with petroleum benzene (3×25 mL)
16. customThe cake was dried under vacuum overnight to a final weight of 6.48 g