Reacción #164944

Ecuación de reacción

2-bromo-5-methyl-pyridine

3-bromo-5-(4,4,5,5-tetramethyl-[1,3,2]-dioxaborolan-2-yl)-benzoic acid methyl ester

K3PO4

→

3-bromo-5-(5-methyl-pyridin-2-yl)-benzoic acid methyl ester

Rendimiento 51.2%

Disolventes

DME

water

Condiciones de reacción

Tratamiento posterior

1. 1
   TemperaturaThe mixture was refluxed for eight hours
2. 2
   Temperaturacooled to room temperature
3. 3
   Otropartitioned between water and EtOAc
4. 4
   LavadoThe combined organic layers were washed with water
5. 5
   Secadodried over MgSO4
6. 6
   Filtraciónfiltered
7. 7
   Concentraciónconcentrated under reduced pressure
8. 8
   OtroThe residue was purified via flash chromatography (5:1 EtOAc/hexanes)

Procedimiento

A mixture of 2-bromo-5-methyl-pyridine (10.27 g, 59.68 mmol) and palladium tetrakis(triphenylphosphine) (1.88 g, 1.65 mmol) in 300 mL DME was stirred at 60° C. under nitrogen for 30 minutes. To this mixture was added 3-bromo-5-(4,4,5,5-tetramethyl-[1,3,2]-dioxaborolan-2-yl)-benzoic acid methyl ester (18.5 g, 54.25 mmol), followed by K3PO4 23.03 g, 108.5 mmol) in 40 mL water. The mixture was refluxed for eight hours, then cooled to room temperature and partitioned between water and EtOAc. The combined organic layers were washed with water, dried over MgSO4, filtered and concentrated under reduced pressure. The residue was purified via flash chromatography (5:1 EtOAc/hexanes) to give 8.5 g of 3-bromo-5-(5-methyl-pyridin-2-yl)-benzoic acid methyl ester, MS (M+H)=306.

Fuente