Réaction #1605780

Équation de réaction

2-bromo-5-methylpyridine

acetonitrile

n-butyl lithium

→

2-(5-methylpyridin-2-yl) acetonitrile

Rendement 80.7%

Solvants

THF

THF

Conditions de réaction

Traitement

1. 1
   workup.WAITThe reaction mixture was kept at minus 78° C. for 1 hour
2. 2
   Températurewarmed up slowly to room temperature
3. 3
   workup.STIRRINGstirred for another hour
4. 4
   Autrethe layer was separated
5. 5
   LavageThe organic layer was washed with water and brine
6. 6
   Séchagedried over MgSO4
7. 7
   Filtrationfiltered
8. 8
   Autreevaporated
9. 9
   Autreto give 18 g of crude product
10. 10
    AutreThe crude product was purified by silica-gel column chromatography (eluent, PE/EtOAc=15:1)

Mode opératoire

To a solution of anhydrous acetonitrile (10.1 mL, 191.83 mmol, 3.3 equiv.) in dry THF (500 mL) was added dropwise n-butyl lithium (2.5 M in hexane, 69.8 mL, 174.39 mmol, 3 equiv.) at minus 78° C. under nitrogen atmosphere. The resulting white suspension was stirred at minus 78° C. for 1 hour, and then a solution of 2-bromo-5-methylpyridine (10.0 g, 58.13 mmol, 1 equiv.) in dry THF (30 mL) was added. The reaction mixture was kept at minus 78° C. for 1 hour and then warmed up slowly to room temperature and stirred for another hour. Ice water was added and the layer was separated. The organic layer was washed with water and brine, dried over MgSO4, filtered, and evaporated to give 18 g of crude product. The crude product was purified by silica-gel column chromatography (eluent, PE/EtOAc=15:1) to give 2-(5-methylpyridin-2-yl) acetonitrile (6.2 g, yield 80%). 1H NMR (300 MHz, CDCl3): δ 8.40 (d, J=3.0 Hz, 1H), 7.54 (dd, J1=3.0 Hz, J2=6.0 Hz, 1 H), 7.32 (d, J=6.0 Hz, 1 H), 3.90 (s, 2H), 2.40 (s, 3H).

Source