Reaction #2275446

Reaction equation

5-bromo-2-(3,4-dichlorophenoxy)benzaldehyde

Na2CO3

potassium acetate

2-bromopyridine

bis(pinacolato)diboron

→

title product

5-(2-Pyridyl)benzaldehyde

Solvents

DMF

Conditions

Workup

1. 1
   OtherUnder N2 in a flame-dried 25 mL round bottomed flask fitted with a magnetic stirrer
2. 2
   OtherThe mixture was degassed with N2 for 5 min.
3. 3
   TemperatureThe mixture was again heated to 80° C. under N2 for a total of 10.5 hr
4. 4
   Temperatureto cool to room temperature overnight
5. 5
   OtherThe mixture was partitioned between EtOAc and H2O
6. 6
   Washthe organic layer was washed with water, brine
7. 7
   Dryingdried over Na2CO3
8. 8
   Concentrationconcentrated in vacuo to an oil, 359 mg
9. 9
   WashChromatography on silica gel, eluting with a gradient system of CHCl3 (100-97% and CH3OH (0-3%)

Procedure

Under N2 in a flame-dried 25 mL round bottomed flask fitted with a magnetic stirrer was placed 200 mg (0.58 mmol) of 5-bromo-2-(3,4-dichlorophenoxy)benzaldehyde, 162 mg (0.64 mmol) of bis(pinacolato)diboron (Frontier Scientific Co.), 170 mg (1.7 mmol) of potassium acetate and 13 mg (0.018 mmol) of dichloro [1,1′-bis(diphenylphosphino)ferrocene]palladium (II) dichloromethane adduct (PdCl2(dppf), Strem Chemicals) in 5 mL of anhydrous DMF. The mixture was degassed with N2 for 5 min. and then heated at 80° C. for 2.5 hr. To this was added 110 μL (1.2 mmol) of 2-bromopyridine, followed by 13 mg of PdCl2(dppf) and 0.7 mL of 2 N aqueous Na2CO3. The mixture was again heated to 80° C. under N2 for a total of 10.5 hr, then allowed to cool to room temperature overnight. The mixture was partitioned between EtOAc and H2O, the organic layer was washed with water, brine and dried over Na2CO3, then concentrated in vacuo to an oil, 359 mg. Chromatography on silica gel, eluting with a gradient system of CHCl3 (100-97% and CH3OH (0-3%) gave the title product as a light brown oil, 44 mg.

Source