3-Methyl-but-2-enoic acid 4-bromo-phenyl ester → 2H-1-Benzopyran-2-one, 6-bromo-3,4-dihydro-4,4-dimethyl-

HRID 381041

Reaktionsgleichung

Reaktionsgleichung von HRID 381041
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([O:8][C:9](=[O:14])[CH:10]=[C:11]([CH3:13])[CH3:12])=[CH:4][CH:3]=1.[Cl-].[Al+3].[Cl-].[Cl-]>ClCCl>[Br:1][C:2]1[CH:3]=[C:4]2[C:5](=[CH:6][CH:7]=1)[O:8][C:9](=[O:14])[CH2:10][C:11]2([CH3:12])[CH3:13]

Komponenten

4

Edukt 2

HCID 7337973-Methyl-but-2-enoic acid 4-bromo-phenyl esterHCID 6451240Aluminum(III) Chloride

Produkt 1

HCID 225689232H-1-Benzopyran-2-one, 6-bromo-3,4-dihydro-4,4-dimethyl-Ausbeute 59,7 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 6344DichloromethaneLösungsmittel

Versuchsvorschrift

A solution of 3-methyl-but-2-enoic acid 4-bromo-phenyl ester (7 g, 27.6 mmol) in anhydrous dichloromethane (200 mL) was cooled (ice bath) and treated with aluminum chloride (6.6 g, 49.6 mmol) and the reaction mixture was stirred overnight at ambient temperature. The reaction mixture was quenched with saturated aqueous sodium bicarbonate solution and extracted with diethyl ether (×2). The combined organic extract was washed with brine (×1), dried over anhydrous sodium sulfate, filtered and evaporated in vacuo to afford an oil which was purified by flash column chromatography over silica gel (230-400 mesh) using 2.5% ethyl acetate in hexane as the eluent to afford the title compound (4.2 g, 57%).

Aufarbeitung

  1. customThe reaction mixture was quenched with saturated aqueous sodium bicarbonate solution
  2. extractionextracted with diethyl ether (×2)
  3. extractionThe combined organic extract
  4. washwas washed with brine (×1)
  5. dry with materialdried over anhydrous sodium sulfate
  6. filtrationfiltered
  7. customevaporated in vacuo
  8. customto afford an oil which
  9. customwas purified by flash column chromatography over silica gel (230-400 mesh)

Quellen und Nachweise

ORD-Eintrag
ord-2d552d7ab3b8473a9427396d735d6537
Quelldatensatz
uspto-grants-2001_10
Patentnummer
US06303785B1

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