Piperonal → 5-(2,2-Dibromo-vinyl)-benzo[1,3]dioxole

HRID 24024

反応式

HRID 24024 の反応式
[CH:1]1[C:6]([CH:7]=O)=[CH:5][C:4]2[O:9][CH2:10][O:11][C:3]=2[CH:2]=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.[C:31](Br)(Br)([Br:33])[Br:32]>C(Cl)Cl>[Br:32][C:31]([Br:33])=[CH:7][C:6]1[CH:1]=[CH:2][C:3]2[O:11][CH2:10][O:9][C:4]=2[CH:5]=1

参加物

5

反応物 3

HCID 8438PiperonalHCID 11205Carbon tetrabromideHCID 11776Triphenylphosphine

生成物 1

HCID 109687645-(2,2-Dibromo-vinyl)-benzo[1,3]dioxole収率 74%

試薬・触媒・溶媒 1

HCID 6344Dichloromethane溶媒

実験手順

To a solution of piperonal (4.5 g, 30 mmol) and triphenylphosphine (24 g, 90 mmol) in DCM (120 mL) in an ice-water bath was added a solution of carbontetrabromide (15 g, 45 mmol) over a 10 minutes period. After the addition completed, the ice-water bath was removed, the reaction stirred at ambient temperature for 2 h, and then quenched with saturated NaHCO3. Aqueous was separated, and extracted with dichloromethane (2 times). The organic layers were combined, dried over Na2SO4, filtered, and concentrated to give a redish colored residue, that was filtered through a short path silica gel plug, eluting with DCM/hexane (10% to 20%). Concentration of the filtrate gave the title compound (6.5 g, 74% yield) as a pale yellow liquid. 1H NMR (CDCl3) δ 7.36 (s, 1H), 7.18 (d, 1H, J=1.6 Hz), 6.95 (dd, 1H, J=1.5, 8.1 Hz), 6.79 (d, 1H, J=8.1 Hz), 5.99 (s, 2H).

後処理

  1. additionAfter the addition
  2. customthe ice-water bath was removed
  3. customquenched with saturated NaHCO3
  4. customAqueous was separated
  5. extractionextracted with dichloromethane (2 times)
  6. dry with materialdried over Na2SO4
  7. filtrationfiltered
  8. concentrationconcentrated
  9. customto give a redish colored residue, that
  10. filtrationwas filtered through a short path silica gel plug
  11. washeluting with DCM/hexane (10% to 20%)

出典と根拠

ORDレコード
ord-b1d78607255e4db591db91c514e39db9
出典データセット
uspto-grants-2005_02
特許番号
US06855722B2

関連ノート

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