At room temperature, 320 g (2.00 mol) of diethyl malonate was added to a sodium ethoxide solution obtained from 46.0 g (2.00 mol) of sodium ethoxide and 1000 cm³ of anhydrous ethanol. The resulting mixture was stirred at room temperature for 30 minutes, and then 274 g (2.00 mol) of isobutyl bromide was added. The resulting mixture was refluxed for 5 hours, and then the ethanol was evaporated. 1500 ml of cold water and 500 ml of ethyl acetate were added to the cooled residue. The organic layer was separated, dried with Na₂SO₄, and then evaporated to dryness.
The residue was fractionally distilled to give 357 g of a colorless liquid with a boiling point of 177-187 °C/220 mmHg. The product contained approximately 10% diethyl isobutylmalonate.
