1-(4-Nitrophenyl)-2-dimethylamino-1,3-propanediol → (S)-2-(4-difluoromethoxyphenyl)-3-methylbutyric acid

Participants

Reaction Steps

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.

Provenance & Evidence