Reacción #7255

Ecuación de reacción

DMF

TMEDA

n-butyl lithium

3-fluoropyridine

→

title compound

Rendimiento 37.3%

3-fluoro-pyridine-4-carboxaldehyde

Rendimiento 37.3%

Disolventes

THF

THF

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.WAITAfter another 2 hours at −78° C.
2. 2
   workup.WAITAfter a further 2 hours at −78° C.
3. 3
   Otrothe reaction was quenched with saturated aqueous NaHCO3 (20 mL)
4. 4
   Extracciónextracted with ether (4×15 mL)
5. 5
   Secadodried (Na2SO4)
6. 6
   Filtraciónfiltered
7. 7
   Concentraciónconcentrated in vacuo
8. 8
   Otroto give the crude oil
9. 9
   OtroPurification by column chromatography on silica gel (Hexanes: EtOAc 4:1)

Procedimiento

To a solution of TMEDA (389 uL, 2.58 mmol) in THF (10 mL) at −78° C. was added a solution of n-butyl lithium in THF (2.5M, 1.03 mL, 2.58 mmol). After 30 minutes at −78° C., 3-fluoropyridine (221 uL, 2.57 mmol) was added. After another 2 hours at −78° C., DMF (219 uL, 2.83 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 pale yellow oil (120 mg, 37%). 1H NMR (CDCl3) 7.68 (t, 1H, J=5.2 Hz), 8.62 (d, 1H, J=4.7 Hz), 8.70 (s, 1H), 10.42 (s, 1H).

Fuente