Reaktion #43601

Reaktionsgleichung

3-bromo-4-hydroxy-5-methoxybenzaldehyde

boron tribromide

→

desired product

Ausbeute 100.0%

3-Bromo-4,5-dihydroxybenzaldehyde

Ausbeute 100.0%

Lösungsmittel

dichloromethane

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.WAITat ambient temperature for 2.5 h
2. 2
   TemperaturThe reaction was then cooled to 0°
3. 3
   Sonstigequenched by the slow addition of methanol
4. 4
   SonstigeThe solvents were removed under reduced pressure
5. 5
   Sonstigethe trimethyl borate was removed by azeotropation with added methanol
6. 6
   SonstigeDrying in vacuo

Vorschrift

To a solution of 3-bromo-4-hydroxy-5-methoxybenzaldehyde (12.1 g, 0.52 mol) in dichloromethane (200 ml) was added 1.0 M boron tribromide in dichloromethane (2.2 eq, 115 ml) at 0°. The reaction was stirred at 0° for 20 min, then at ambient temperature for 2.5 h. The reaction was then cooled to 0°, and quenched by the slow addition of methanol. The solvents were removed under reduced pressure and the trimethyl borate was removed by azeotropation with added methanol. Drying in vacuo yielded the desired product (11.51 g, 100%).

Quelle