반응 #71078

반응 방정식

n-BuLi

N2

2,4-dibromo-pyridine

N,N-Dimethyl-formamide

→

title compound

2-Bromo-pyridine-4-carbaldehyde

용매

—

hexanes

Et2O

반응 조건

후처리

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

실험 절차

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.

출처