Boron tribromide → 3-Chloro-4,5-dihydroxybenzaldehyde

HRID 2569

Reaktionsgleichung

Reaktionsgleichung von HRID 2569
[Cl:1][C:2]1[C:3]([OH:12])=[C:4]([O:10]C)[CH:5]=[C:6]([CH:9]=1)[CH:7]=[O:8].B(Br)(Br)Br>ClCCl>[Cl:1][C:2]1[CH:9]=[C:6]([CH:5]=[C:4]([OH:10])[C:3]=1[OH:12])[CH:7]=[O:8]

Komponenten

4

Edukt 2

HCID 25134Boron tribromideHCID 296223-Chloro-4-hydroxy-5-methoxybenzaldehyde

Produkt 1

HCID 24681823-Chloro-4,5-dihydroxybenzaldehydeAusbeute 77,3 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 6344DichloromethaneLösungsmittel2×

Reaktionsbedingungen

Temperatur
0 °C

Versuchsvorschrift

37.2 g of commercial 5-chloro vanillin and 800 ml of dichloromethane were mixed together under nitrogen and cooled to 0° C. 300 ml of a molar solution of boron tribromide in dichloromethane are added and the mixture stood for one night at ambient temperature. It was concentrated, cooled again to 0° C. and acidified. The crystallized product was separated, washed with water, dried and crystallized from an isopropanol- water mixture (1-2 by volume) to obtain 26.6 g of the expected product melting at >260° C.

Aufarbeitung

  1. waitthe mixture stood for one night at ambient temperature
  2. concentrationIt was concentrated
  3. temperaturecooled again to 0° C.
  4. customThe crystallized product was separated
  5. washwashed with water
  6. customdried
  7. customcrystallized from an isopropanol- water mixture (1-2 by volume)

Quellen und Nachweise

ORD-Eintrag
ord-49d72313e0d6412c95d675c45339c241
Quelldatensatz
uspto-grants-1998_03
Patentnummer
US05728828

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