Hydrochloric Acid → 1,3-Diethyl 2-(1-oxopropyl)propanedioate

Temperature

7.5 °C

To a mixture of diethyl malonate (704 g, e.g. available from Spectrochem) and acetonitrile (3.8 L) was added anhydrous magnesium chloride immediately (419 g, e.g. available from Lancaster). Triethylamine (1222 ml) was added dropwise, maintaining the temperature at 5-10° C., followed by the dropwise addition of propionyl chloride (406 g), maintaining the temperature at or below 30° C. The reaction mixture was kept at 10-15° C. for 1 hour, and then the mixture was kept overnight at room temperature. The next day, aqueous hydrochloric acid (1 M) was added to the reaction mixture until the pH of the mixture was about 2.0 (approx. 4.8 L was required). The mixture was extracted with diethyl ether (3×800 ml). The combined ethereal extracts were washed with aqueous hydrochloric acid (1M, 2×1000 ml), followed by water (2×1000 mL) and finally with brine (2×1000 mL). Evaporation of the solvent from the ethereal extracts under reduced pressure afforded diethyl propanoylpropanedioate (845 g) as a yellow oil.

1. temperaturemaintaining the temperature at or below 30° C
2. waitthe mixture was kept overnight at room temperature
3. extractionThe mixture was extracted with diethyl ether (3×800 ml)
4. washThe combined ethereal extracts were washed with aqueous hydrochloric acid (1M, 2×1000 ml)
5. customEvaporation of the solvent from the ethereal extracts under reduced pressure

ORD record

ord-b3787e9a769f4b7f882a91ee374fe0fc

Source dataset

uspto-grants-2011_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08003663B2