Sulfuric Acid → Ethyl 2,4-dioxoheptanoate

Participants

Reaction Steps

To refluxing solution of sodium ethoxide (51.2 g, 0.75 mmol) in ethanol (170 ml) was added dropwise over 30 minutes a solution of 2-pentanone (59 g, 0.68 mol) in diethyl oxalate (99 g, 0.68 mol). The resulting turbid yellow mixture was refluxed further for 2 hours, cooled to room temperature, poured over 500 g ice with stirring and adjusted to pH 1-2 with concentrated sulfuric acid (~40 ml). The organic phase was extracted with benzene (3×300 ml), washed once with saturated aqueous sodium chloride and dried over anhydrous sodium sulfate, before being filtered, concentrated, and fractionally distilled at 0.1 mm Hg to give 48.2 g (38%) of the title compound as a yellow liquid; b.p. 85-95° C.

Provenance & Evidence