反应详情

The 5-ethyl-6-hydroxy-3-(4-methoxy-carbonylbutyl)-5-phenyl-2,4 (3H,5H)-pyrimidinedione ester (54.0 g, 0.156 mole) of step 1 in dioxane (500 mL), concentrated hydrochloric acid (55 mL), and water (55 mL) was heated at reflux for 4 hrs and at room temperature overnight. The dioxane was removed under reduced pressure, and saturated sodium chloride solution (250 mL) and dichloromethane (400 mL) were added to the residue. The organic layer was separated, and the aqueous solution was extracted with dichloromethane (3×150 mL). The combined organic solutions were washed with saturated sodium chloride solution (200 mL), dried over anhydrous MgSO4, filtered, and the solvent removed. To the residue was added diethyl ether, and the mixture was placed in a freezer at -16° C. over the weekend, and then filtered.

1. customThe dioxane was removed under reduced pressure, and saturated sodium chloride solution (250 mL) and dichloromethane (400 mL)
2. additionwere added to the residue
3. customThe organic layer was separated
4. extractionthe aqueous solution was extracted with dichloromethane (3×150 mL)
5. washThe combined organic solutions were washed with saturated sodium chloride solution (200 mL)
6. dry with materialdried over anhydrous MgSO4
7. filtrationfiltered
8. customthe solvent removed
9. additionTo the residue was added diethyl ether
10. customwas placed in a freezer at -16° C. over the weekend
11. filtrationfiltered