反应详情

3,4-Dimethoxyphenethylamine 42a (3.62 g, 3.4 mL, 20 mmol, 1.0 eq) was added to a solution of 4-(trifluoromethyl)hydrocinnamic acid 43 (4.36 g, 20 mmol, 1.0 eq) in toluene (75 mL). After 5 min a thick suspension formed. The suspension was heated to reflux, giving a clear solution. The mixture was heated at reflux for 24 h using a Dean-Stark trap to remove water that was formed. The mixture was partially cooled, diluted with ethyl acetate (100 mL) and concentrated under reduced pressure to near dryness. The thick slurry was diluted with ethyl acetate (200 mL) and the solution washed sequentially with 1N hydrochloric acid (100 mL), aqueous sodium bicarbonate solution (200 mL), water (100 mL) and brine (100 mL). The organic solution was dried over sodium sulfate, filtered and the filtrate concentrated under reduced pressure. The solid was triturated with heptanes (50 mL), filtered and dried to give 5.37 g (70%) of 44a as a white, fluffy solid.

1. customAfter 5 min a thick suspension formed
2. temperatureThe suspension was heated
3. temperatureto reflux
4. customgiving a clear solution
5. temperatureThe mixture was heated
6. temperatureat reflux for 24 h
7. customto remove water that
8. customwas formed
9. temperatureThe mixture was partially cooled
10. concentrationconcentrated under reduced pressure
11. additionThe thick slurry was diluted with ethyl acetate (200 mL)
12. washthe solution washed sequentially with 1N hydrochloric acid (100 mL), aqueous sodium bicarbonate solution (200 mL), water (100 mL) and brine (100 mL)
13. dry with materialThe organic solution was dried over sodium sulfate
14. filtrationfiltered
15. concentrationthe filtrate concentrated under reduced pressure
16. customThe solid was triturated with heptanes (50 mL)
17. filtrationfiltered
18. customdried