Potassium Hydroxide → Diethyl (2-phenylpropan-2-yl)propanedioate

HRID 249404

Reaction equation

[C:1]1([Mg]Br)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[C:9](=[C:12]([C:18]([O:20][CH2:21][CH3:22])=[O:19])[C:13]([O:15][CH2:16][CH3:17])=[O:14])([CH3:11])[CH3:10].[OH-].[K+]>C(O)C>[CH3:10][C:9]([CH:12]([C:18]([O:20][CH2:21][CH3:22])=[O:19])[C:13]([O:15][CH2:16][CH3:17])=[O:14])([CH3:11])[C:1]1[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1

Participants

Conditions

Temperature: 50 °C

Procedure

Diethyl (α,α-dimethylbenzyl)malonate was prepared by the congugate addition of phenyl magnesium bromide to diethyl isopropylidenemalonate as described by C. Holmberg [Liebigs Ann. Chem., 748 (1981)]. A solution of this diester (42.1 g, 0.15 mole) in ethanol (100 mL) was treated by dropwise addition with a solution of potassium hydroxide (8.48 g, 0.13 mole) in 100 mL of ethanol. After heating at 90° C. for 1 h and at 50° C. for 20 h, the reaction mixture was evaporated on the rotary evaporator to a residue. The residue was diluted with water and extracted with ether to remove unreacted starting material. The aqueous phase was cooled to 5° C., acidified to pH 3, with 6N HCl and extracted with methylene chloride. The organic layer was washed with brine solution and dried over magnesium sulfate. Evaporation of the solvent gave 27.3 g (84%) of liquid product. NMR (CDCl3): 1.05 (3H, t), 1.6 (6H, s), 3.78 (1H, s), 3.96 (2H, m), 7.2-7.4 (5H, m).

Workup

customthe reaction mixture was evaporated on the rotary evaporator to a residue
additionThe residue was diluted with water
extractionextracted with ether
customto remove unreacted
temperatureThe aqueous phase was cooled to 5° C.
extractionextracted with methylene chloride
washThe organic layer was washed with brine solution
dry with materialdried over magnesium sulfate
customEvaporation of the solvent

Sources & evidence

ORD record: ord-33deeba48eb840eb86a3ae864677223c
Source dataset: uspto-grants-1993_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05214129

Linked notes

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