反应详情

Dissolve 50 g of 2-(4-difluoromethoxyphenyl)-3-methylbutyric acid in 150 g of ethyl alcohol and to this solution is added 0.24 mole of resolving agent 1-(4-nitrophenyl)-2-dimethylamino-1,3-propanediol. Heat the solution with stirring under reflux for 1.5 hours, then cool, filter, and transfer the resulting solids to 73 g of 10% hydrochloric acid. Heat the mixture with stirring at 30° C. for 2 hours and then allow the mixture to cool to room temperature. The resulting mixture is extracted with benzene 2-3 times, and the solvent benzene is then removed by distillation to give 21.25 g (yield: 42.5%) of (S)-2-(4-difluoromethoxyphenyl)-3-methylbutyric acid.

1. additionto this solution is added 0.24 mole
2. temperatureHeat the solution
3. temperatureunder reflux for 1.5 hours
4. temperaturecool
5. filtrationfilter
6. temperatureHeat the mixture
7. stirringwith stirring at 30° C. for 2 hours
8. extractionThe resulting mixture is extracted with benzene 2-3 times
9. customthe solvent benzene is then removed by distillation