Benzyl Bromide → 2,4-Pentanedione, 3-benzyl-

HRID 1064543

反応式

HRID 1064543 の反応式
[O-]CC.[Na+].[H-].[Na+].[CH3:7][C:8](=[O:13])[CH2:9][C:10](=[O:12])[CH3:11].[CH2:14](Br)[C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1>C(O)C>[CH2:14]([CH:9]([C:8](=[O:13])[CH3:7])[C:10](=[O:12])[CH3:11])[C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1

参加物

6

反応物 4

HCID 7498Benzyl BromideHCID 24758Sodium hydrideHCID 31261AcetylacetoneHCID 2723922Sodium ethoxide

生成物 1

HCID 977572,4-Pentanedione, 3-benzyl-収率 82.3%

試薬・触媒・溶媒 1

HCID 702Ethanol溶媒2 回

実験手順

To a solution of sodium ethoxide (freshly prepared from sodium hydride (0.474 g, 19.8 mmol) and anhydrous ethanol (50 mL)) was added pentane-2,4-dione (6.00 g, 60.0 mmol). The resulting mixture was heated to 50° C. while a solution of benzyl bromide (3.42 g, 20 mmol) in ethanol (20 mL) was added over 30 minutes. The reaction was then heated to reflux. After 2 hours, the mixture was concentrated, and the residue was dissolved in ethyl acetate, washed three times with water, once with brine, dried (magnesium sulfate) and concentrated to afford an oil. Flash chromatography over silica (ethyl acetate/dichloromethane) afforded 3.13 g (82%) of a colorless oil. The proton spectrum showed the product exists as equal parts of the keto and enol tautomers: 1H NMR (CDCl3) δ 16.81 (s, 0.5H), 7.13-7.32 (m, 5H), 4.00 (t, J=7.6 Hz, 0.5H), 3.65 (s, 1H), 3.14 (d, J=7.6 Hz, 0.5H), 2.06-2.13 (m, 6H) ppm.

後処理

  1. additionwas added over 30 minutes
  2. temperatureThe reaction was then heated to reflux
  3. concentrationthe mixture was concentrated
  4. dissolutionthe residue was dissolved in ethyl acetate
  5. washwashed three times with water
  6. dry with materialonce with brine, dried (magnesium sulfate)
  7. concentrationconcentrated
  8. customto afford an oil

出典と根拠

ORDレコード
ord-84fe8a4ccbc646d5980c678b6cdc7eeb
出典データセット
uspto-grants-2005_11
特許番号
US06969728B2

関連ノート

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