Reacción #929050

Ecuación de reacción

3,5-dibromosalicylaldehyde

acetic anhydride

triethylamine

→

6,8-dibromocoumarin

Rendimiento 87.0%

Condiciones de reacción

Tratamiento posterior

1. 1
   TemperaturaThe reaction solution was heated overnight
2. 2
   Temperaturaat reflux under argon
3. 3
   Otroa solid mass formed
4. 4
   LavadoThe dark brown reaction mixture was washed with hot hexanes (3×300 mL) and aqueous saturated sodium bicarbonate
5. 5
   workup.DISSOLUTIONThe resulting solid was dissolved in EtOAc (2 L)
6. 6
   Lavadowashed with water
7. 7
   SecadoThe organic layer was dried (sodium sulfate)
8. 8
   Concentraciónconcentrated
9. 9
   Otroto give a brown solid
10. 10
    Filtraciónthat was collected by filtration
11. 11
    OtroThe solid was dried in vacuo

Procedimiento

To a suspension of 3,5-dibromosalicylaldehyde (100 g, 357 mmol) in acetic anhydride (164.8 mL, 1.8 mol) was added triethylamine (45 mL, 375 mmol). The reaction solution was heated overnight at reflux under argon. The solution was cooled to room temperature and a solid mass formed. The dark brown reaction mixture was washed with hot hexanes (3×300 mL) and aqueous saturated sodium bicarbonate. The resulting solid was dissolved in EtOAc (2 L) and washed with water. The organic layer was dried (sodium sulfate) and concentrated to give a brown solid that was collected by filtration. The solid was dried in vacuo to give substantially pure 6,8-dibromocoumarin (94.2 g, 87% yield).

Fuente