Reacción #71078

Ecuación de reacción

n-BuLi

N2

2,4-dibromo-pyridine

N,N-Dimethyl-formamide

→

title compound

2-Bromo-pyridine-4-carbaldehyde

Disolventes

—

hexanes

Et2O

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.STIRRINGstirred at this temperature for 20 min
2. 2
   OtroThe reaction was quenched by the addition of sat. aq. NH4Cl (30 mL)
3. 3
   OtroThe layers were separated
4. 4
   Extracciónthe aq. layer extracted with Et2O (3×50 mL)
5. 5
   Secadoextracts were dried over Na2SO4
6. 6
   Filtraciónfiltered
7. 7
   Otrothe solvent removed under reduced pressure
8. 8
   OtroPurification of the residue by FC (10:1 to 2:1 hept-EA)

Procedimiento

In a flame dried round-bottomed flask equipped with a magnetic stir bar and under inert atmosphere (N2), a suspension of 2,4-dibromo-pyridine (1.90 g, 8.02 mmol) in dry Et2O (40 mL) was treated with n-BuLi (3.36 mL of a 2.5M solution in hexanes, 8.42 mmol) at −78° C. The reaction mixture was stirred at this temperature for 30 min. N,N-Dimethyl-formamide (0.78 mL, 10.03 mmol) was then added and the mixture allowed to warm to rt over a period of 1 h and stirred at this temperature for 20 min. The reaction was quenched by the addition of sat. aq. NH4Cl (30 mL). The layers were separated and the aq. layer extracted with Et2O (3×50 mL). The combined org. extracts were dried over Na2SO4, filtered, and the solvent removed under reduced pressure. Purification of the residue by FC (10:1 to 2:1 hept-EA) gave the title compound as a white solid. TLC:rf (1:1 hept-EA)=0.44.

Fuente