Ethyl Acetate → 2-(2,4-Dimethyl-phenyl)-malonic acid dimethyl ester

HRID 8599

Reaction equation

HRID 8599 reaction equation
[O-]P([O-])([O-])=O.[K+].[K+].[K+].Br[C:10]1[CH:15]=[CH:14][C:13]([CH3:16])=[CH:12][C:11]=1[CH3:17].[CH3:18][C:19](=[O:23])[O:20][CH2:21]C>C1COCC1.CC([O-])=O.CC([O-])=O.[Pd+2]>[CH3:21][O:20][C:19](=[O:23])[CH:18]([C:10]1[CH:15]=[CH:14][C:13]([CH3:16])=[CH:12][C:11]=1[CH3:17])[C:19]([O:20][CH3:21])=[O:23]

Participants

6

Reactant 3

HCID 8857Ethyl AcetateHCID 62657Potassium Phosphate, TribasicHCID 68503Benzene, 1-bromo-2,4-dimethyl-

Product 1

HCID 688971052-(2,4-Dimethyl-phenyl)-malonic acid dimethyl ester

Reagents, catalysts & solvents 2

HCID 167845palladium(II) acetateCatalystHCID 8028TetrahydrofuranSolvent

Procedure

(In analogy to a procedure given in J. Am. Chem. Soc. 122 (2000), 1360–1370.) To a suspension of Pd(OAc)2 (758 mg), 2-(di-tert.-butlylphosphino)-biphenyl (2.02 g) and K3PO4 (65.95 g) in THF (350 ml) dimethylmalonate (21.42 g) and 1-bromo-2,4-dimethyl-benzene (25 g) was added under argon. The mixture was refluxed for 96 h, cooled to rt and diluted with EA (300 ml) and filtered. The filtrate was evaporated and the resulting brown oil was purified on silica gel eluting with heptane:EA 4:1 to 1:1 followed by distillation (bp 95–100° C. at 0.064 mbar) to give 2-(2,4-dimethyl-phenyl)-malonic acid dimethyl ester (5.66 g) as a colourless oil. 1H-NMR(300 MHz, CDCl3): 2.30(s, 6H), 3.75(s, 6H), 4.87(s, 1H), 6.98–7.05(m, 2H), 7.25–7.28(m, 1H).

Workup

  1. additionwas added under argon
  2. temperatureThe mixture was refluxed for 96 h
  3. filtrationfiltered
  4. customThe filtrate was evaporated
  5. customthe resulting brown oil was purified on silica gel eluting with heptane:EA 4:1 to 1:1
  6. distillationfollowed by distillation (bp 95–100° C. at 0.064 mbar)

Sources & evidence

ORD record
ord-82f8576a87f140efbfe729c5f4cccf25
Source dataset
uspto-grants-2006_08
Patent number
US07091201B2

Linked notes

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