Potassium Carbonate → 6-Hydroxy-2-methyl-1-benzofuran-3-carboxylic acid

HRID 2261831노트

반응식

HRID 2261831 반응식
[Cl-].[Cl-].[Cl-].[Al+3].C(Cl)(=O)C(Cl)=O.[CH3:11][C:12]1[O:13][C:14]2[CH:20]=[C:19]([O:21]C(=O)C)[CH:18]=[CH:17][C:15]=2[CH:16]=1.[C:25](=O)([O-:27])[O-:26].[K+].[K+]>ClCCl>[OH:21][C:19]1[CH:18]=[CH:17][C:15]2[C:16]([C:25]([OH:27])=[O:26])=[C:12]([CH3:11])[O:13][C:14]=2[CH:20]=1

참가 물질

6

반응물 4

HCID 11430Potassium CarbonateHCID 65578Oxalyl chlorideHCID 6451240Aluminum(III) ChlorideHCID 221435562-Methylbenzofuran-6-yl acetate

생성물 1

HCID 221435296-Hydroxy-2-methyl-1-benzofuran-3-carboxylic acid수율 99.7%

시약·촉매·용매 1

HCID 6344Dichloromethane용매2회

반응 조건

온도
0 °C

실험 절차

To a slurry of aluminum trichloride (20.0 g, 150 mmol) in dichloromethane (200 mL) is added oxalyl chloride (13.0 mL, 150 mmol) and the mixture is stirred at 0° C. for 30 minutes. A solution of acetic acid 2-methyl-benzofuran-6-yl ester (9.50 g; 49.9 mmol) in dichloromethane (50 mL) is added over 10 minutes. The ice-bath is removed and the reaction is stirred at room temperature for 2 hours. The reaction mixture is cooled to 0° C. and quenched with MeOH (50 mL). The mixture is concentrated to a residue, dissolved in methanol (250 mL), and treated with potassium carbonate (8.28 g, 59.9 mmol). The mixture is stirred at room temperature for 16 hours, filtered through a pad of celite, and concentrated. The residue is diluted with water (100 mL) and extracted with EtOAc (250 mL×2). The combined organic layers are dried over Na2SO4, filtered, and concentrated. The crude product is purified by flash chromatography (eluted with 25% EtOAc/Hexanes), and the appropriate fractions are concentrated. The material is dried in vacuo to afford 6-hydroxy-2-methyl-benzofuran-3-carboxylic acid (9.56 g, 93%). ES/MS m/e 207.0 (M+1); 205.0 (M−1).

후처리

  1. customThe ice-bath is removed
  2. stirringthe reaction is stirred at room temperature for 2 hours
  3. temperatureThe reaction mixture is cooled to 0° C.
  4. customquenched with MeOH (50 mL)
  5. concentrationThe mixture is concentrated to a residue
  6. dissolutiondissolved in methanol (250 mL)
  7. stirringThe mixture is stirred at room temperature for 16 hours
  8. filtrationfiltered through a pad of celite
  9. concentrationconcentrated
  10. additionThe residue is diluted with water (100 mL)
  11. extractionextracted with EtOAc (250 mL×2)
  12. dry with materialThe combined organic layers are dried over Na2SO4
  13. filtrationfiltered
  14. concentrationconcentrated
  15. customThe crude product is purified by flash chromatography (eluted with 25% EtOAc/Hexanes)
  16. concentrationthe appropriate fractions are concentrated
  17. customThe material is dried in vacuo

출처 및 근거

ORD 기록
ord-56418295301649d5b86ba2e958379af3
출처 데이터셋
uspto-grants-2010_12
특허 번호
US07846960B2

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