Potassium Phosphate, Dibasic → 7-(4-Methoxyphenyl)-benzofuran-4-carbaldehyde

HRID 1372154Notes

Reaction equation

HRID 1372154 reaction equation
[CH3:1][O:2][C:3]1[CH:8]=[CH:7][C:6]([C:9]2[C:17]3[O:16][CH:15]=[CH:14][C:13]=3[C:12]([CH3:18])=[CH:11][CH:10]=2)=[CH:5][CH:4]=1.C1C(=O)N(Br)C(=[O:22])C1.OP([O-])([O-])=O.[K+].[K+]>C(Cl)(Cl)(Cl)Cl.CC(N=NC(C#N)(C)C)(C#N)C>[CH3:1][O:2][C:3]1[CH:4]=[CH:5][C:6]([C:9]2[CH:10]=[CH:11][C:12]([CH:18]=[O:22])=[C:13]3[C:17]=2[O:16][CH:15]=[CH:14]3)=[CH:7][CH:8]=1

Participants

6

Reactant 3

HCID 24450Potassium Phosphate, DibasicHCID 67184N-bromobutanimideHCID 210717957-(4-Methoxyphenyl)-4-methylbenzofuran

Product 1

HCID 210717977-(4-Methoxyphenyl)-benzofuran-4-carbaldehydeYield 75%

Reagents, catalysts & solvents 2

HCID 6547AzobisisobutyronitrileCatalystHCID 5943Carbon TetrachlorideSolvent

Procedure

To a solution of 7-(4-methoxyphenyl)-4-methylbenzofuran (1.27 g, 5.34 mmol) in carbon tetrachloride (150 ml) was added NBS (1.05 g, 5.87 mmol) and AIBN (50 mg). The solution was brought to reflux for 2 h, cooled to room temperature, and the solids were filtered off. The solution was then concentrated and anhydrous CH3CN (50 ml) was added. Then potassium benzeneselenite (Syper, Ludwik; Mlochowski, Jacek Synthesis 1984, 9, 747–752) (1.33 g, 5.87 mmol), and K2HPO4 (0.93 g, 5.34 mmol) were added and the reaction was heated to reflux for 1 h after which it was allowed to cool to room temperature. The solution was then passed through a silica plug and the plug was washed with 30% EtOAc/hexanes after which the CH3CN was stripped off under hi vacuum. Chromatography (100% CH2Cl2) removed the Ph2Se2 by-product to afford 1.0 g (75%) of product as a white solid: mp 143–144° C.; 1H NMR (300 MHz, DMSO-d6): δ 3.85 (3H, s), 7.15 (2H, d, J=8.7 Hz), 7.57 (1H, d, J=2.1 Hz), 7.75 (1H, d, J=7.8 Hz), 7.96 (3H, appt), 8.33 (1H, d, J=2.1 Hz), 8.04 (1H, d, J=2.2 Hz); MS (ESI) m/z 253 ([M+H]+).

Workup

  1. temperatureto reflux for 2 h
  2. filtrationthe solids were filtered off
  3. concentrationThe solution was then concentrated
  4. additionanhydrous CH3CN (50 ml) was added
  5. temperaturethe reaction was heated
  6. temperatureto reflux for 1 h after which it
  7. temperatureto cool to room temperature
  8. washthe plug was washed with 30% EtOAc/hexanes after which the CH3CN
  9. customChromatography (100% CH2Cl2) removed the Ph2Se2 by-product

Sources & evidence

ORD record
ord-7944c38519a343bcb14d766fb78925b1
Source dataset
uspto-grants-2007_01
Patent number
US07157491B2

Reaction notes

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