Réaction #7253

Équation de réaction

DMF

TMEDA

n-butyl lithium

3-chloropyridine

→

title compound

Rendement 27.0%

3-chloro-pyridine-2-carboxaldehyde

Rendement 27.0%

Solvants

ether

ether

Conditions de réaction

Traitement

1. 1
   workup.WAITAfter another 2 hours at −78° C.
2. 2
   workup.WAITAfter a further 2 hours at −78° C.
3. 3
   Autrethe reaction was quenched with saturated aqueous NaHCO3 (20 mL)
4. 4
   Extractionextracted with ether (4×15 mL)
5. 5
   Séchagedried (Na2SO4)
6. 6
   Filtrationfiltered
7. 7
   Concentrationconcentrated in vacuo
8. 8
   Autreto give the crude oil
9. 9
   AutrePurification by column chromatography on silica gel (Hexanes: EtOAc 4:1)

Mode opératoire

To a solution of TMEDA (660 uL, 2.58 mmol) in ether (20 mL) at −78° C. was added a solution of n-butyl lithium in ether (2.5 M, 1.76 mL, 4.40 mmol). After 30 minutes at −78° C., 3-chloropyridine (419 uL, 4.40 mmol) was added. After another 2 hours at −78° C., DMF (375 uL, 4.84 mmol) was added. After a further 2 hours at −78° C., the reaction was quenched with saturated aqueous NaHCO3 (20 mL), extracted with ether (4×15 mL), dried (Na2SO4), 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 (168 mg, 27%). 1H NMR (CDCl3) 7.45 (dd, 1H, J=8.3, 4.4 Hz), 7.83 (dd, 1H, J=4.8, 1.4 Hz), 8.70 (dd, 1H, J=4.8, 1.5 Hz), 10.28 (s, 1H).

Source