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

Participants

Reaction Conditions

Reaction Steps

To a stirred suspension of magnesium ethoxide (3.56 g, 31.2 mmol) in anhydrous toluene (10 ml) at RT is added a solution of diethyl malonate (5 g, 31.2 mmol) in toluene (40 ml). The mixture is stirred at 50° C. for 2.5 hrs (until all the solid dissolved) then cooled to 8-10° C. (note: solidification occurs at 5° C.). To this solution is added slowly propionyl chloride (2.7 ml, 31.2 mmol). The reaction mixture is warmed to ambient temperature and stirring continues for 2 hrs. The reaction mixture is cooled to 5-10° C. and treated with 1M HCl (approx. 35 ml, 1.1 equiv.) to adjust the pH to approx. 1-3. The mixture is allowed to warm to RT and treated with sat. aq. NaHCO3 to give a pH of 6-7. The layers are separated and the organic layer is washed with brine, dried (Na2SO3) and concentrated in vacuo to afford the title compound as a viscous orange oil; 1H NMR (400 MHz, CDCl3) δ [13.45 (s) and 4.47 (s) combined 1H], 4.15-4.30 (4H, m), [2.66 (q, J 7.2) and 2.48 (q, J 7.5) combined 2H], 1.30 (6H, m), [1.21 (t, J 7.5) and 1.12 (t, J 7.2) combined 3H].

Provenance & Evidence