反应详情

Dissolve 50 g of 2-(4-difluoromethoxyphenyl)-3-methylbutyric acid in 130 g of toluene 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 6 hours, then cool, filter, and transfer the resulting solids to 48.7 g of 15% hydrochloric acid. Heat the mixture with stirring at 40° 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 21.75 g (yield: 43.5%) 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 6 hours
4. temperaturecool
5. filtrationfilter
6. temperatureHeat the mixture
7. stirringwith stirring at 40° C. for 2 hours
8. extractionThe resulting mixture is extracted with benzene 2-3 times
9. customthe solvent benzene is then removed by distillation