Diethyl isopropylmalonate → Diethyl 2-isopropyl-2-propylmalonate

Participants

Reaction Steps

A solution of diethylisopropylmalonate (10.1g) in 15 ml of a 25% solution of HMPT (hexamethylphosphorus triamide) in toluene was added dropwise over 15 minutes to a suspension of sodium hydride (70 mM) in 25% HMPT/toluene (15 ml) at 50°-70° C. N-propyl iodide (17.0g) was then added over 30 minutes at 70°-100° C. and the mixture stirred at 120°-130° C. for 11/2 hours. After cooling, methylated spirits (10 ml) was added and the mixture poured onto a mixture of ice/hydrochloric acid. The product was extracted with ether, the ethereal extracts washed with sodium bicarbonate (X2), then water and dried over anhydrous magnesium sulphate. Removal of the solvent gave diethyl 2-isopropyl-2-propylmalonate as a yellow liquid b.p. 92°-94°/1 mm Hg. 87% yield.

Provenance & Evidence