1,2-Dibromoethane → 6-Methyl-2,3-dihydro-1,4-benzodioxine

HRID 395250ノート

反応式

HRID 395250 の反応式
[CH3:1][C:2]1[CH:3]=[C:4]([OH:9])[C:5](=[CH:7][CH:8]=1)[OH:6].Br[CH2:11][CH2:12]Br.C([O-])([O-])=O.[K+].[K+]>C(O)CO.[I-].[Na+]>[CH3:1][C:2]1[CH:8]=[CH:7][C:5]2[O:6][CH2:11][CH2:12][O:9][C:4]=2[CH:3]=1

参加物

6

反応物 3

HCID 78391,2-DibromoethaneHCID 99584-MethylcatecholHCID 11430Potassium Carbonate

生成物 1

HCID 124003766-Methyl-2,3-dihydro-1,4-benzodioxine収率 50%

試薬・触媒・溶媒 2

HCID 5238Sodium Iodide触媒HCID 174Ethylene Glycol溶媒

反応条件

温度
130 °C

実験手順

A mixture of 4-methylcatechol (33.04 g, 266.1 mmol), 1,2-dibromoethane (100 g, 532.3 mmol), K2CO3 (75.4 g, 545.5 mmol) and sodium iodide (0.2 g, 1.33 mmol) in ethylene glycol (500 mL) was heated to 130° C. under nitrogen for five hours. The solution was allowed to cool to ambient temperature and stirred overnight. After the mixture was filtered through celite, the solution was diluted with brine (800 mL) and extracted with organic solvents (CH2Cl2/hexane/EtOAc: 1:3:1,3×500 mL). The organic layer was dried over Na2SO4, filtered and concentrated to provide a crude oil. Flash silica gel chromatography eluting with hexane (100%) gradient to ether/hexane (8:2) afforded the title intermediate as a colorless oil 20.0 g (50%).

後処理

  1. temperatureto cool to ambient temperature
  2. filtrationAfter the mixture was filtered through celite
  3. additionthe solution was diluted with brine (800 mL)
  4. extractionextracted with organic solvents (CH2Cl2/hexane/EtOAc: 1:3:1,3×500 mL)
  5. dry with materialThe organic layer was dried over Na2SO4
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customto provide a crude oil
  9. washFlash silica gel chromatography eluting with hexane (100%) gradient to ether/hexane (8:2)

出典と根拠

ORDレコード
ord-36989a97950047ca804b9329f2cd9f52
出典データセット
uspto-grants-2003_08
特許番号
US06605596B2

反応ノート

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