Sulfuric Acid → 4-Bromo-5-formyl-benzo[1,3]dioxole-2-carboxylic acid methyl ester

HRID 47911

반응식

HRID 47911 반응식
[Br:1][C:2]1[C:9]([OH:10])=[C:8]([OH:11])[CH:7]=[CH:6][C:3]=1[CH:4]=[O:5].[C:12]([O-])([O-])=O.[K+].[K+].Br[CH:19](Br)[C:20]([OH:22])=[O:21].OS(O)(=O)=O>C(O)CC.CO.O>[CH3:12][O:22][C:20]([CH:19]1[O:11][C:8]2[CH:7]=[CH:6][C:3]([CH:4]=[O:5])=[C:2]([Br:1])[C:9]=2[O:10]1)=[O:21]

참가 물질

8

반응물 4

HCID 1118Sulfuric AcidHCID 11430Potassium CarbonateHCID 12433Dibromoacetic Acid2회HCID 131095752-Bromo-3,4-dihydroxybenzaldehyde

생성물 1

HCID 875788404-Bromo-5-formyl-benzo[1,3]dioxole-2-carboxylic acid methyl ester

시약·촉매·용매 3

HCID 887Methanol용매HCID 962Water용매HCID 10311-Propanol용매2회

실험 절차

To a mixture of 2-bromo-3,4-dihydroxy-benzaldehyde (2.17 g, 10.0 mmol) and K2CO3 (5.56 g, 40.2 mmol) in n-propanol (25 mL) was added dibromoacetic acid (2.18, 10.0 mmol) and the mixture was heated at reflux temperature for 24 h. After cooling to room temperature, another portion of dibromoacetic acid (1.75 g, 8.0 mmol) was added. The mixture was stirred at reflux for 46 h. n-Propanol was evaporated and water (30 mL) was added. The resulting aqueous solution was acidified to pH 2 by adding 1 N HCl and extracted with ethyl acetate (3×100 mL). The combined organic layers were dried (MgSO4) and evaporated in vacuo to afford crude 4-bromo-5-formyl-benzo[1,3]dioxole-2-carboxylic acid (1.34 g) as a brownish solid. This crude product was dissolved in anhydrous methanol (50 mL) and conc. H2SO4 (5 mL) was added drop by drop. The resulting mixture was refluxed overnight and cooled to room temperature. Water (50 mL) was added and the resulting aqueous solution was extracted with ethyl acetate (100 mL×3). The combined organic layers were dried (MgSO4) and evaporated in vacuo. The residue was purified by flash column chromatography (ethyl acetate:hexane=5:95) to furnish 4-bromo-5-formyl-benzo[1,3]dioxole-2-carboxylic acid methyl ester as a white solid.

후처리

  1. temperaturethe mixture was heated
  2. temperatureat reflux temperature for 24 h
  3. customwas evaporated
  4. additionwater (30 mL) was added
  5. additionby adding 1 N HCl
  6. extractionextracted with ethyl acetate (3×100 mL)
  7. dry with materialThe combined organic layers were dried (MgSO4)
  8. customevaporated in vacuo
  9. customto afford crude 4-bromo-5-formyl-benzo[1,3]dioxole-2-carboxylic acid (1.34 g) as a brownish solid
  10. temperatureThe resulting mixture was refluxed overnight
  11. temperaturecooled to room temperature
  12. extractionthe resulting aqueous solution was extracted with ethyl acetate (100 mL×3)
  13. dry with materialThe combined organic layers were dried (MgSO4)
  14. customevaporated in vacuo
  15. customThe residue was purified by flash column chromatography (ethyl acetate:hexane=5:95)

출처 및 근거

ORD 기록
ord-6a88c84769cd4133add1015337f6909e
출처 데이터셋
uspto-grants-2004_03
특허 번호
US06699994B1

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