Potassium Carbonate → 5-Methoxy-2-methylbenzaldehyde

HRID 1748721Notes

Reaction equation

HRID 1748721 reaction equation
Br[C:2]1[CH:9]=[CH:8][C:7]([O:10][CH3:11])=[CH:6][C:3]=1[CH:4]=[O:5].[CH3:12]B1OB(C)OB(C)O1.C(=O)([O-])[O-].[K+].[K+]>O1CCOCC1.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[CH3:11][O:10][C:7]1[CH:8]=[CH:9][C:2]([CH3:12])=[C:3]([CH:6]=1)[CH:4]=[O:5]

Participants

6

Reactant 3

HCID 11430Potassium CarbonateHCID 3444802-Bromo-5-methoxybenzaldehydeHCID 574072Trimethylboroxine2×

Product 1

HCID 123475665-Methoxy-2-methylbenzaldehydeYield 92%

Reagents, catalysts & solvents 2

HCID 178418397HCID 178418397, compoundCatalyst2×HCID 312751,4-DioxaneSolvent

Procedure

To a degassed solution of 2-bromo-5-methoxybenzaldehyde (1.5 g, 7.04 mmol, Fluorochem) and trimethylboroxine (0.98 mL, 7.04 mmol) in 1,4-dioxane (80 mL) was added potassium carbonate (2.91 g, 21.1 mmol) and tetrakis(triphenylphosphine)palladium(0) (0.813 g, 0.70 mmol). The mixture was heated under reflux for about 20 h, then more tetrakis(triphenylphosphine)palladium(0) (0.200 g, 0.17 mmol) and trimethylboroxine (0.25 mL, 1.8 mmol) were added and the mixture was heated under reflux for about another 3 h. After cooling to rt the mixture was filtered over diatomaceous earth and concentrated in vacuo. The residue was purified by column chromatography (SiO2, diethyl ether/hexanes 1:3) to give 5-methoxy-2-methyl-benzaldehyde (0.97 g, 92%) as a colorless liquid. 1H-NMR (CDCl3, Bruker 400 MHz) 2.60 (3 H, s); 3.83 (3 H, s); 7.04 (1 H, dd, J=8.5 Hz, 2.4 Hz); 7.16 (1 H, d, J=8.5 Hz); 7.33 (1 H, d, J=2.4 Hz); 10.2 (1 H, s).

Workup

  1. temperatureThe mixture was heated
  2. temperatureunder reflux for about 20 h
  3. temperaturethe mixture was heated
  4. temperatureunder reflux for about another 3 h
  5. filtrationwas filtered over diatomaceous earth
  6. concentrationconcentrated in vacuo
  7. customThe residue was purified by column chromatography (SiO2, diethyl ether/hexanes 1:3)

Sources & evidence

ORD record
ord-559434159a6a4946a5b2e2ff900d40b2
Source dataset
uspto-grants-2015_10
Patent number
US09150592B2

Reaction notes

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