Ethyl Acetate → 2-(3,4-Dimethyl-phenyl)-malonic acid dimethyl ester

HRID 8598

Reaction equation

HRID 8598 reaction equation
[O-]P([O-])([O-])=O.[K+].[K+].[K+].Br[C:10]1[CH:15]=[CH:14][C:13]([CH3:16])=[C:12]([CH3:17])[CH:11]=1.[CH3:18][C:19](=[O:23])[O:20][CH2:21]C>C1COCC1.CC([O-])=O.CC([O-])=O.[Pd+2].C(P(C(C)(C)C)C1C=CC=CC=1C1C=CC=CC=1)(C)(C)C>[CH3:21][O:20][C:19](=[O:23])[CH:18]([C:10]1[CH:15]=[CH:14][C:13]([CH3:16])=[C:12]([CH3:17])[CH:11]=1)[C:19]([O:20][CH3:21])=[O:23]

Participants

7

Reactant 3

HCID 8857Ethyl AcetateHCID 62657Potassium Phosphate, TribasicHCID 685044-Bromo-o-xylene

Product 1

HCID 688978002-(3,4-Dimethyl-phenyl)-malonic acid dimethyl ester

Reagents, catalysts & solvents 3

HCID 167845palladium(II) acetateCatalystHCID 27342152-(Di-tert-butylphosphino)biphenylCatalystHCID 8028TetrahydrofuranSolvent

Procedure

(In analogy to a procedure given in J. Am. Chem. Soc. 122 (2000), 1360-1370.) To a suspension of Pd(OAc)2 (455 mg), 2-(di-tert.-butylphosphino)-biphenyl (1.21 g) and K3PO4 (39.6 g) in THF (200 ml) dimethylmalonate (12.85 g) and 1-bromo-3,4-dimethyl-benzene 15.0 g) was added under argon. The mixture was refluxed for 16 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 to give 2-(3,4-dimethyl-phenyl)-malonic acid dimethyl ester (16.2 g) as a colourless oil which slowly crystallises. 1H-NMR (300 MHz, CDCl3): 2.25(s, 3H), 2.26(s, 3H), 3.75(s, 6H), 4.59(s, 1H), 7.10–7.20(m, 3H).

Workup

  1. additionwas added under argon
  2. temperatureThe mixture was refluxed for 16 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

Sources & evidence

ORD record
ord-a49db3e4ff1840bf80f49c0406a40f8c
Source dataset
uspto-grants-2006_08
Patent number
US07091201B2

Linked notes

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