1,1'-Carbonyldiimidazole → Ethyl 5,5-diethoxy-3-oxopentanoate

Participants

Reaction Conditions

Reaction Steps

To a solution of 16 mL of 3-ethoxy-3-oxomalonic acid (135 mmol) in 40 mL of tetrahydrofuran there are added, under argon, 21.9 g of powdered magnesium (90.4 mmol). The mixture obtained is then heated at 80° C. for 7 hours. After returning to ambient temperature, this mixture is transferred by cannula to a solution of 10 g of the compound obtained in Step A (61.7 mmol) in 64 mL of tetrahydrofuran to which there has previously been added, in portions, 11 g of carbonyldiimidazole (66 mmol). The reaction mixture is stirred for 3 days at ambient temperature. After concentration, the residue is taken up in a mixture of ethyl acetate and aqueous sodium hydrogen sulphate (NaHSO4) solution. The mixture is stirred vigorously until no more gas is evolved. After separation of the phases, the organic phase is washed successively with water, saturated aqueous NaHCO3 solution and finally brine. After drying over MgSO4 and concentrating to dryness, the title product is obtained in the form of an oil which is used in the next Step without being otherwise purified.

Provenance & Evidence