Reaktion #7256

Reaktionsgleichung

DMF

TMEDA

LDA

3-bromo-pyridine

→

title compound

Ausbeute 51.0%

3-bromo-pyridine-4-carboxaldehyde

Ausbeute 51.0%

Lösungsmittel

ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeAfter 1 hour at room temperature the reaction was quenched with saturated aqueous NaHCO3 (100 mL)
2. 2
   Extraktionextracted with CH2Cl2 (4×15 mL)
3. 3
   Trocknendried (MgSO4)
4. 4
   Filtrationfiltered
5. 5
   Einengenconcentrated in vacuo
6. 6
   Sonstigeto give the crude oil
7. 7
   SonstigePurification by column chromatography on silica gel (Hexanes: EtOAc 4:1)

Vorschrift

To a solution of TMEDA (1.91 mL, 12.7 mmol) and LDA (12.7 mmol) in ether (50 mL) at −78° C. was added 3-bromo-pyridine (1.22 mL, 12.7 mmol). After 60 minutes at −78° C., DMF (1.08 mL, 13.9 mmol) was added, and the mixture allowed to warm to room temperature. After 1 hour at room temperature the reaction was quenched with saturated aqueous NaHCO3 (100 mL), extracted with CH2Cl2 (4×15 mL), dried (MgSO4), filtered and concentrated in vacuo to give the crude oil. Purification by column chromatography on silica gel (Hexanes: EtOAc 4:1) afforded the title compound as a crystalline solid (1.2 g, 51%). 1H NMR (CDCl3) 7.70 (d, 1H, J=4.8 Hz), 8.71 (d, 1H, J=4.8 Hz), 8.91 (s, 1H), 10.36 (s, 1H).

Quelle