Diethyl Malonate → diethyl(2,2-dimethylpropylidene)propanedioate

Participants

Reaction Conditions

Reaction Steps

In 1-liter flask, to a mixture of 320 g (2.0 mol) of diethyl malonate, 172 g (2.0 mol) of pivalaldehyde, and 256 g (2.51 mol) of acetic anhydride 38.4 g (0.28 mol) of ZnCl2 was added in one portion by vigorous stirring. This mixture was spontaneously warmed to ca. 105° C. The formed red mixture was refluxed for 36 h, then cooled to ambient temperature, and 800 ml of toluene was added. This solution was washed by 3×500 ml of water. The combined aqueous solution was extracted with 2×350 ml of toluene. The combined toluene extract and solution was dried over K2CO3, passed through ca. 7 cm layer of silica gel 60 (40-63 um) on glass frit, and then evaporated to dryness. Fractional rectification of the residue gave yellowish oil of the title product, b.p. 132-135° C./20 mm Hg. Yield 254 g (56%).

Provenance & Evidence