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

HRID 1525469Notes

Reaction equation

[C:1]([O:9][CH2:10][CH3:11])(=[O:8])[CH2:2][C:3]([O:5][CH2:6][CH3:7])=[O:4].[CH:12](=O)[C:13]([CH3:16])([CH3:15])[CH3:14].C(OC(=O)C)(=O)C>[Cl-].[Cl-].[Zn+2].C1(C)C=CC=CC=1>[CH3:12][C:13]([CH3:16])([CH3:15])[CH:14]=[C:2]([C:3]([O:5][CH2:6][CH3:7])=[O:4])[C:1]([O:9][CH2:10][CH3:11])=[O:8]

Participants

Conditions

Temperature: 105 °C

Procedure

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%).

Workup

additionwas added in one portion by vigorous stirring
temperatureThe formed red mixture was refluxed for 36 h
temperaturecooled to ambient temperature
washThis solution was washed by 3×500 ml of water
extractionThe combined aqueous solution was extracted with 2×350 ml of toluene
extractionThe combined toluene extract
dry with materialsolution was dried over K2CO3
customevaporated to dryness

Sources & evidence

ORD record: ord-43489d172d2a471bab347e9c2dd3e3bf
Source dataset: uspto-grants-2015_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09079985B2

Reaction notes

Loading…