反应详情

温度

50 °C

114 g (0.60 mol) of 2,4,5-trifluorophenylacetic acid was dissolved in 600 mL of THF. To this mixture, 107 g (0.66 mol) of carbonyldiimidazole was added with stirring (when a part of carbonyldiimidazole was added, a lot of solid was formed; subsequently, the solid thereby dissolved in the solution with further addition). Upon completion of the addition, the reaction mixture was warmed to 50° C. 95.1 g (0.66 mol) of Meldrum's acid was added, and the mixture was aged for 3 hours at 50° C. The mixture was concentrated to remove THF and the residue was dissolved in water (600 mL) and dichloromethane (800 mL), and then the pH value was adjusted to 2. The aqueous phase was separated and the organic phase was washed with 0.1N HCl and water (600 mL) respectively. The organic phase was dried and concentrated to obtain 182 g of a condensate, 5-[2-(2,4,5-trifluorophenyl)-acetyl]-2,2-dimethyl-1,3-dioxane-4,6-dione, as a solid (the re-crystallization can be carried out in ethyl acetate to obtain a white solid). Melting point: 101.5-103.5° C., Yield: 96%.

1. additionwas added
2. customa lot of solid was formed
3. dissolutionsubsequently, the solid thereby dissolved in the solution with further addition)
4. additionUpon completion of the addition
5. concentrationThe mixture was concentrated
6. customto remove THF
7. dissolutionthe residue was dissolved in water (600 mL)
8. customThe aqueous phase was separated
9. washthe organic phase was washed with 0.1N HCl and water (600 mL) respectively
10. customThe organic phase was dried
11. concentrationconcentrated