Diethyl Malonate → Ethyl (pentafluorobenzoyl)acetate

Participants

Reaction Steps

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.

Provenance & Evidence