3-Bromotoluene → Ethyl (4-bromo-2-methylphenyl)(oxo)acetate

HRID 583912Notes

Reaction equation

HRID 583912 reaction equation
[Al+3].[Cl-].[Cl-].[Cl-].Cl[C:6](=[O:12])[C:7]([O:9][CH2:10][CH3:11])=[O:8].[Br:13][C:14]1[CH:15]=[C:16]([CH3:20])[CH:17]=[CH:18][CH:19]=1.[Cl-].[NH4+]>ClC(Cl)C.[Au]>[Br:13][C:14]1[CH:19]=[CH:18][C:17]([C:6](=[O:12])[C:7]([O:9][CH2:10][CH3:11])=[O:8])=[C:16]([CH3:20])[CH:15]=1

Participants

7

Reactant 4

HCID 115603-BromotolueneHCID 20884Ethoxalyl chlorideHCID 25517Ammonium ChlorideHCID 6451240Aluminum(III) Chloride

Product 1

HCID 20820234Ethyl (4-bromo-2-methylphenyl)(oxo)acetateYield 51.1%

Reagents, catalysts & solvents 2

HCID 23985GoldCatalystHCID 63651,1-DichloroethaneSolvent

Procedure

To a suspension of AlCl3 (20.3 g, 152 mmol) in dichloroethane (250 mL, DCE) was added ethyl chlorooxoacetate (16.8 g, 123 mmol) at room temperature. To the resulting gold solution was added 3-bromotoluene (20.0 g, 117 mmol) and the dark solution was stirred at room temperature for 4 h. The reaction was cooled to 0° C. and saturated aqueous ammonium chloride was slowly added. The phases were separated and the DCE layer was washed with additional ammonium chloride, dried (Na2SO4), filtered, and the DCE removed in vacuo to give the crude product as a gold oil. Flash chromatography (SiO2; 0-3% Et2O/Hexanes) gave ethyl (4-bromo-2-methylphenyl)-(oxo)acetate (16.2 g; 33%) as a gold oil. 1H NMR (CDCl3) δ 1.41 (t, 3H, J=7.0 Hz), 2.58 (s, 3H), 4.43 (q, 2H, J=7.0 Hz), 7.44-7.48 (m, 2H), 7.58 (d, 1H, J=8.0 Hz); EI/MS 271 m/e (M+). Ethyl (4-bromo-2-methylphenyl)-(methoxyimino)ethanoate

Workup

  1. temperatureThe reaction was cooled to 0° C.
  2. customThe phases were separated
  3. washthe DCE layer was washed with additional ammonium chloride
  4. dry with materialdried (Na2SO4)
  5. filtrationfiltered
  6. customthe DCE removed in vacuo
  7. customto give the crude product as a gold oil

Sources & evidence

ORD record
ord-ace4dd2a06f849279b09a65fec989f0e
Source dataset
uspto-grants-2005_08
Patent number
US06924298B2

Reaction notes

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