Diethyl 2-(ethoxymethylidene)-3-oxobutanedioate → HCID 18937855, compound

Participants

Reaction Conditions

Reaction Steps

Diethyl ethoxymethyleneoxalacetate (150.4 g, 0.616 mol, 1 eq) is dissolved in 300 mL absolute ethanol under a nitrogen atmosphere and the mixture is cooled to -10° C. in an ice/acetone bath. Unpurified 1-nitro-2-propanone (prepared by the method of D. Baker and S. Putt, Synthesis, 1978, 478-9, assumed to be 63.448 g, 0.616 mol) dissolved in 100 mL absolute ethanol is then added to the stirred solution. Sodium acetate (101.06 g, 1,232 mol) is then added in portions so that the temperature of the reaction remains below 10° C., followed by the addition of ammonium acetate (94.6 g, 1,232 g). The reaction mixture is allowed to warm to room temperature and is then stirred for 16 hours. The mixture is filtered through two pads of silica gel which are then eluted with methylene chloride. The filtrate is concentrated in vacuo to a thick dark oil which is chromatographed using hexanes as eluant, yielding the product in an 18.2% yield (31.4 g), having a melting point 90°-91.5° C.

Provenance & Evidence