反应详情

The hydroxy acid obtained above, 18.43 g. (0.093 mole) was dissolved in 200 ml. of ethyl acetate with gentle warming and to the solution was addeda solution of 15.04 g. (0.91 mole) of d-ephedrine, [α]578 =(+)11.4 (acetone), in 80 ml. ethyl acetate. The mixture was stirred at room temperature over night during which time a crop of crystals formed, was removed by filtration and air dried to obtain 18.3 g., M.P. 97°-99° C. This material was recrystallized by dissolving itin a minimum amount of hot ethyl acetate and allowing to stand at ambient temperature over night. After three such recrystallizations, 8.9 g. of thed-ephedrine salt of l-4-hydroxy-4-(p-fluorophenyl)butyric acid, M.P. 105.5°-106.5° C. was obtained.

1. dissolution(0.093 mole) was dissolved in 200 ml
2. customformed
3. customwas removed by filtration and air
4. customdried
5. customto obtain 18.3 g
6. customThis material was recrystallized
7. dissolutionby dissolving itin a minimum amount of hot ethyl acetate
8. waitto stand at ambient temperature over night
9. customAfter three such recrystallizations, 8.9 g