反应详情

A solution of 5-(4-fluorobenzyl)-2,2-dimethyl-1,3-dioxane-4,6-dione (34.118 g, 135.26 mmol, Intermediate 7: step a) and 6 M aqueous NaOH (136 mL) was heated to 120° C. under a reflux condenser and positive pressure of nitrogen for two days. The mixture was allowed to cool to room temperature, water and ethyl acetate were added, and the layers were separated. The aqueous layer was acidified to pH 0 with 6 M aqueous HCl and the mixture was stirred at room temperature for 30 minutes. Dichloromethane was added to the mixture, the organic layer was separated, and the aqueous layer was extracted with excess ethyl acetate. The combined organic layers were dried (Na2SO4), filtered, and concentrated to dryness to provide the title compound.

1. customthe layers were separated
2. additionDichloromethane was added to the mixture
3. customthe organic layer was separated
4. extractionthe aqueous layer was extracted with excess ethyl acetate
5. dry with materialThe combined organic layers were dried (Na2SO4)
6. filtrationfiltered
7. concentrationconcentrated to dryness