反応 #71078

反応方程式

n-BuLi

N2

2,4-dibromo-pyridine

N,N-Dimethyl-formamide

→

title compound

2-Bromo-pyridine-4-carbaldehyde

溶媒

—

hexanes

Et2O

反応条件

後処理

1. 1
   workup.STIRRINGstirred at this temperature for 20 min
2. 2
   その他The reaction was quenched by the addition of sat. aq. NH4Cl (30 mL)
3. 3
   その他The layers were separated
4. 4
   抽出the aq. layer extracted with Et2O (3×50 mL)
5. 5
   乾燥extracts were dried over Na2SO4
6. 6
   ろ過filtered
7. 7
   その他the solvent removed under reduced pressure
8. 8
   その他Purification of the residue by FC (10:1 to 2:1 hept-EA)

実験手順

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.

出典