1,3-Dimethoxybenzene → 2,4,4'-Trimethoxy-alpha-methyldesoxybenzoin

HRID 480221

Reaction equation

HRID 480221 reaction equation
[CH3:1][O:2][C:3]1[CH:8]=[CH:7][C:6]([CH:9]([CH3:13])[C:10]([OH:12])=O)=[CH:5][CH:4]=1.[CH3:14][O:15][C:16]1[CH:21]=[CH:20][CH:19]=[C:18]([O:22][CH3:23])[CH:17]=1>>[CH3:14][O:15][C:16]1[CH:17]=[C:18]([O:22][CH3:23])[CH:19]=[CH:20][C:21]=1[C:10]([CH:9]([CH3:13])[C:6]1[CH:5]=[CH:4][C:3]([O:2][CH3:1])=[CH:8][CH:7]=1)=[O:12]

Participants

3

Reactant 2

HCID 90251,3-DimethoxybenzeneHCID 257576p-Methoxyphenylpropionic acid

Product 1

HCID 206016342,4,4'-Trimethoxy-alpha-methyldesoxybenzoinYield 58%

Conditions

Temperature
75 °C

Procedure

2-(p-Methoxyphenyl)propionic acid (0.39 g, 4 mmol) and 1,3-dimethoxybenzene (0.5 g, 0.5 ml, 4 mmol) were mixed in polyphosphoric acid (PPA) (10 g) and the reaction mixture was mechanically stirred at 75° C. for 5 h. The reaction mixture was then allowed to cool to room temperature and mechanically stirred for a further 12 h. The reaction was then quenched with ice water and the product extracted with CHCl3 (3×25 ml). The CHCl3 layer was dried (Na2SO4) and the solvent removed under reduced pressure. The residual crude product was purified by silica gel column chromatography (eluent 7:2 CH2Cl2:EtOAc) to give the pure 2,4,4′-trimethoxy-α-methyldesoxybenzoin (0.68 g,58%)

Workup

  1. temperatureto cool to room temperature
  2. stirringmechanically stirred for a further 12 h
  3. customThe reaction was then quenched with ice water
  4. extractionthe product extracted with CHCl3 (3×25 ml)
  5. dry with materialThe CHCl3 layer was dried (Na2SO4)
  6. customthe solvent removed under reduced pressure
  7. customThe residual crude product was purified by silica gel column chromatography (eluent 7:2 CH2Cl2:EtOAc)

Sources & evidence

ORD record
ord-8e031a8a46b94a078abbe548b86703e6
Source dataset
uspto-grants-2003_11
Patent number
US06649648B1

Linked notes

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