Reaction #2320125

Reaction equation

2-Bromo-5-methylpyridine

3-bromophenylboronic acid

triphenylphosphine

potassium carbonate

→

2-(3-bromophenyl)-5-methylpyridine

Yield 68.1%

Solvents

ethyl acetate

water

ethylene glycol dimethyl ether

Conditions

Workup

1. 1
   Otherequipped with a temperature probe
2. 2
   Temperaturereflux condenser, and a magnetic stir bar
3. 3
   TemperatureThe solution was heated
4. 4
   Temperatureat reflux under nitrogen for 16 hr
5. 5
   OtherThe cooled reaction mixture
6. 6
   Otherwas then placed in a separatory funnel
7. 7
   ExtractionThe organic layer was extracted twice with a saturated solution of sodium chloride
8. 8
   Dryingdried over magnesium sulfate
9. 9
   Otherevaporated to dryness
10. 10
    workup.DISTILLATIONAfter the excess 2-bromo-5-methylpyridine was distilled off in vacuo at 110° C.
11. 11
    workup.DISTILLATIONthe 2-(3-bromophenyl)-5-methylpyridine was distilled at 200° C.
12. 12
    Otherto give 30.1 g (68.1% yield) of a slightly orange liquid, which
13. 13
    Otherwas used for the next step without further purification

Procedure

2-Bromo-5-methylpyridine (46.1 g, 267 mmol), 3-bromophenylboronic acid (35.8 g, 178 mmol), palladium(II) acetate (1.00 g, 4.4 mmol), triphenylphosphine (4.67 g, 17.8 mmol), and potassium carbonate (67.8 g, 491 mmol) were mixed with 370 mL of ethylene glycol dimethyl ether and 245 mL of water in a 1000 mL round bottom flask equipped with a temperature probe, reflux condenser, and a magnetic stir bar. The solution was heated at reflux under nitrogen for 16 hr. The cooled reaction mixture was then placed in a separatory funnel, and 100 mL of ethyl acetate was added. The aqueous layer was discarded. The organic layer was extracted twice with a saturated solution of sodium chloride, dried over magnesium sulfate, and evaporated to dryness. After the excess 2-bromo-5-methylpyridine was distilled off in vacuo at 110° C., the 2-(3-bromophenyl)-5-methylpyridine was distilled at 200° C. to give 30.1 g (68.1% yield) of a slightly orange liquid, which was used for the next step without further purification.

Source