1,2-Dibromoethane → 2,3-dihydro-1,4-benzodioxin-5-ylmethanol

HRID 910085ノート

反応式

HRID 910085 の反応式
[OH:1][C:2]1[C:9]([OH:10])=[CH:8][CH:7]=[CH:6][C:3]=1[CH:4]=[O:5].Br[CH2:12][CH2:13]Br.C(=O)([O-])[O-].[Cs+].[Cs+].[BH4-].[Na+]>CN(C)C=O.C(O)C>[O:10]1[C:9]2[CH:8]=[CH:7][CH:6]=[C:3]([CH2:4][OH:5])[C:2]=2[O:1][CH2:13][CH2:12]1

参加物

7

反応物 4

HCID 78391,2-DibromoethaneHCID 10796Cesium carbonateHCID 905792,3-DihydroxybenzaldehydeHCID 4311764Sodium borohydride

生成物 1

HCID 27761822,3-dihydro-1,4-benzodioxin-5-ylmethanol

試薬・触媒・溶媒 2

HCID 702Ethanol溶媒HCID 6228Dimethylformamide溶媒

反応条件

温度
20 °C

実験手順

Dissolve 2,3-Dihydroxybenzaldehyde (25 g, 181 mmol) and 1,2-dibromoethane (34 g, 181 mmol) in N,N-dimethylformamide (500 mL). Add cesium carbonate (118 g, 362 mmol), stir and reflux under nitrogen for 2 hours. Cool the reaction to 20° C., dilute with absolute ethanol (250 mL) and add sodium borohydride (6.8 g, 181 mmol). Stir at 20° C. for 1 hour and concentrate under high vacuum to remove the ethanol and dimethylformamide. Dilute the residue with diethyl ether and wash with distilled water, 0.25 molar aqueous sodium hydroxide, and aqueous saturated sodium chloride. Dry the organic phase over anhydrous magnesium sulfate, filter and concentrate under reduced pressure. Chromatograph on flash silica using a gradient from 75% hexane, 25% ethyl acetate to 25% hexane, 75% ethyl acetate to obtain the title compound as a white solid.

後処理

  1. temperaturereflux under nitrogen for 2 hours
  2. temperatureCool
  3. customthe reaction to 20° C.
  4. concentrationconcentrate under high vacuum
  5. customto remove the ethanol and dimethylformamide
  6. additionDilute the residue with diethyl ether
  7. washwash with distilled water, 0.25 molar aqueous sodium hydroxide, and aqueous saturated sodium chloride
  8. dry with materialDry the organic phase over anhydrous magnesium sulfate
  9. filtrationfilter
  10. concentrationconcentrate under reduced pressure

出典と根拠

ORDレコード
ord-dac42b55d34c4969af7f74e2428a3d9b
出典データセット
uspto-grants-2011_09
特許番号
US08022065B2

反応ノート

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