Sodium Carbonate → Tert-butyl 4-(benzofuran-2-yl)benzoate

HRID 1501077Notes

Reaction equation

HRID 1501077 reaction equation
CC1(C)C(C)(C)OB([C:9]2[CH:21]=[CH:20][C:12]([C:13]([O:15][C:16]([CH3:19])([CH3:18])[CH3:17])=[O:14])=[CH:11][CH:10]=2)O1.Br[C:24]1[O:25][C:26]2[CH:32]=[CH:31][CH:30]=[CH:29][C:27]=2[CH:28]=1.O1CCOCC1.C(=O)([O-])[O-].[Na+].[Na+]>[Pd].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.O>[O:25]1[C:26]2[CH:32]=[CH:31][CH:30]=[CH:29][C:27]=2[CH:28]=[C:24]1[C:9]1[CH:10]=[CH:11][C:12]([C:13]([O:15][C:16]([CH3:17])([CH3:18])[CH3:19])=[O:14])=[CH:20][CH:21]=1

Participants

7

Reactant 4

HCID 10340Sodium CarbonateHCID 312751,4-DioxaneHCID 27762642-Bromo-1-benzofuranHCID 43767661,1-Dimethylethyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzoate

Product 1

HCID 89580933Tert-butyl 4-(benzofuran-2-yl)benzoateYield 67%

Reagents, catalysts & solvents 2

HCID 11979704Tetrakis(triphenylphosphine)palladiumCatalystHCID 962WaterSolvent

Conditions

Temperature
90 °C

Procedure

To a solution of tert-butyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzoate (1.0 g, 3.3 mmol), 2-bromobenzofuran (0.64 g, 3.3 mmol) and tetrakis(triphenylphosphine) palladium(0) (0.5 g, 0.4 mmol) in a mixed solution of 1,4-dioxane (20 mL) and water (2.0 mL) was added sodium carbonate (1.0 g, 7.2 mmol). The reaction mixture was stirred at 90° C. under nitrogen for 12 hours. After the reaction, it was allowed to cool to room temperature, and concentrated in vacuo, then diluted with ethyl acetate (100 mL), washed with water (100 mL). The organic phase was dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated and the residue was purified by column chromatography (silica gel, ethyl acetate/petroleum ether=1:20) to give the pure product tert-butyl 4-(benzofuran-2-yl)benzoate as a white solid (0.65 g, 67%). 1H NMR (300 MHz, CDCl3): δ 8.06 (d, J=8.7 Hz, 2H), 7.90 (d, J=8.4 Hz, 2H), 7.62-7.53 (m, 2H), 7.32-7.25 (m, 2H), 7.14 (s, 1H), 1.62 (s, 9H).

Workup

  1. customAfter the reaction, it
  2. temperatureto cool to room temperature
  3. concentrationconcentrated in vacuo
  4. additiondiluted with ethyl acetate (100 mL)
  5. washwashed with water (100 mL)
  6. dry with materialThe organic phase was dried over anhydrous sodium sulfate
  7. filtrationfiltered
  8. concentrationThe filtrate was concentrated
  9. customthe residue was purified by column chromatography (silica gel, ethyl acetate/petroleum ether=1:20)

Sources & evidence

ORD record
ord-1b833afd42874844ae1646cec3f54531
Source dataset
uspto-grants-2015_12
Patent number
US09206128B2

Reaction notes

Loading…