Diethyl Malonate → Ethyl (pentafluorobenzoyl)acetate

To a solution of 20 g (125 mmol) of diethyl malonate in 80 ml of absolute ethanol was added with stirring a solution of KOH pellets (7 g) in 80 ml of absolute ethanol over a period of 12 minutes and the resulting mixture was stirred at room temperature for 2 hours. The solution was heated to boiling, filtered while hot, and the filtrate was cooled and filtered to afford, after drying, 11.14 g (53%) of potassium ethyl malonate. To a stirred and cooled (10° C.) mixture of the above potassium salt (11.14 g; 66 mmol) in 100 ml of acetonitrile was added triethylamine (6.5 g, 64 mmol) and magnesium chloride (7.5 g, 80 mmol) and the resulting mixture was stirred at room temperature for 2 hours. To the above mixture, cooled to 0° C., was added dropwise pentafluorobenzoyl chloride (7.4 g; 32 mmol) followed by the addition of 0.64 g of triethylamine, and the resulting mixture was allowed to stir at room temperature overnight and then was concentrated to dryness. The resulting mixture was diluted with 40 ml of toluene, concentrated in vacuo, and the residue was rediluted with 60 ml of toluene, stirred, and cooled to 10° C. An aqueous HCl solution (13%; 45 ml) was added in portions to the above reaction mixture at below 25° C., the organic layer was washed with 13% HCl solution (2×12 ml), water, and concentrated in vacuo. The residue was distilled to afford 8.4 g (93%) of ethyl pentafluorobenzoylacetate as an oil, b.p.139°-147° C.

1. temperatureThe solution was heated
2. filtrationfiltered while hot, and the filtrate
3. temperaturewas cooled
4. filtrationfiltered
5. customto afford
6. customafter drying
7. stirringTo a stirred
8. temperaturecooled
9. stirringthe resulting mixture was stirred at room temperature for 2 hours
10. temperatureTo the above mixture, cooled to 0° C.
11. stirringto stir at room temperature overnight
12. concentrationwas concentrated to dryness
13. additionThe resulting mixture was diluted with 40 ml of toluene
14. concentrationconcentrated in vacuo
15. additionthe residue was rediluted with 60 ml of toluene
16. stirringstirred
17. temperaturecooled to 10° C
18. additionAn aqueous HCl solution (13%; 45 ml) was added in portions to the above reaction mixture at below 25° C.
19. washthe organic layer was washed with 13% HCl solution (2×12 ml), water
20. concentrationconcentrated in vacuo
21. distillationThe residue was distilled

ORD record

ord-5cb70864d71746bc9007fc8f23c49536

Source dataset

uspto-grants-1998_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05750550