Boron tribromide → 4-Hydroxy-2,5-dimethyl-benzaldehyde

HRID 1170962Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1170962
[CH3:1][C:2]1[CH:9]=[C:8]([O:10]C)[C:7]([CH3:12])=[CH:6][C:3]=1[CH:4]=[O:5].B(Br)(Br)Br>C(Cl)Cl>[CH3:1][C:2]1[CH:9]=[C:8]([OH:10])[C:7]([CH3:12])=[CH:6][C:3]=1[CH:4]=[O:5]

Komponenten

4

Edukt 2

HCID 25134Boron tribromideHCID 812274-Methoxy-2,5-dimethylbenzaldehyde

Produkt 1

HCID 128272904-Hydroxy-2,5-dimethyl-benzaldehydeAusbeute 57,3 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 6344DichloromethaneLösungsmittel2×

Versuchsvorschrift

First step: To a stirring solution of 2,5-dimethyl-4-methoxybenzaldehyde (0.82 g, 5.0 mmol) at −20° C. in CH2Cl2 (10 mL) was added BBr3 (10 mL, 1M in CH2Cl2). The reaction mixture was stirred at room temperature for 16 hrs. It was added ice and diluted with CH2Cl2. The organic layer was dried over Na2SO4, filtered and concentrated under reduced pressure. The crude product was purified by column chromatography on silica gel, eluting with ethyl acetate/hexanes (1:1) to afford 2,5-dimethyl-4-hydroxy-benzaldehyde as a yellow solid (0.43 g, 57%): 1H NMR (300 MHz, DMSO-d6): δ 10.41 (s, 1 H), 9.99 (s, 1 H), 7.56 (s, 1 H), 6.69 (s, 1 H), 2.51 (s, 3 H), 2.14 (s, 3 H); TLC conditions: Uniplate silica gel, 250 microns; Mobile phase=20% ethyl acetate in hexanes; Rf=0.48.

Aufarbeitung

  1. additionIt was added ice
  2. dry with materialThe organic layer was dried over Na2SO4
  3. filtrationfiltered
  4. concentrationconcentrated under reduced pressure
  5. customThe crude product was purified by column chromatography on silica gel
  6. washeluting with ethyl acetate/hexanes (1:1)

Quellen und Nachweise

ORD-Eintrag
ord-976b1f450b1e4d4cae3a1b1262b1a2a7
Quelldatensatz
uspto-grants-2010_11
Patentnummer
US07829552B2

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