Reaktion #40513

Reaktionsgleichung

tributyltin chloride

n-Butyl lithium

diisopropylamine

3,5-difluoropyridine

→

3,5-Difluoro-4-tributylstannanyl-pyridine

Ausbeute 89.5%

Lösungsmittel

Water

THF

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeat −78° C.
2. 2
   Sonstigeto form
3. 3
   workup.STIRRINGThe reaction stirred at −78° C. for 90 min
4. 4
   Temperaturto warm to RT over 2 h
5. 5
   Sonstigeroughly 250 mL of THF was removed on a rotary evaporator
6. 6
   workup.ADDITIONThe resulting material was diluted with diethyl ether (350 mL)
7. 7
   Waschenwashed successively with water (2×200 mL), saturated sodium chloride solution (1×150 mL)
8. 8
   Trocknendried over magnesium sulfate
9. 9
   Filtrationfiltered
10. 10
    Einengenconcentrated in vacuo

Vorschrift

n-Butyl lithium (1.0 eq, 76 mmol, 47.6 mL, 1.6 M in hexanes) was added via dropping funnel to a solution of diisopropylamine (1.05 eq, 80 mmol, 11.2 mL) in THF (300 mL) at −78° C. under nitrogen (N2). The solution was stirred for 30 min at −78° C., then a solution of 3,5-difluoropyridine (1.05 eq, 80 mmol, 9.2 g) in THF (20 mL) was added dropwise via syringe. A beige precipitate was observed to form. The reaction stirred at −78° C. for 90 min then tributyltin chloride (1.0 eq, 76 mmol, 20.7 mL) was added dropwise via syringe and the resulting solution allowed to warm to RT over 2 h. Water (5 mL) was added, then roughly 250 mL of THF was removed on a rotary evaporator. The resulting material was diluted with diethyl ether (350 mL) and washed successively with water (2×200 mL), saturated sodium chloride solution (1×150 mL), dried over magnesium sulfate, filtered and concentrated in vacuo to afford the 3,5-Difluoro-4-tributylstannanyl-pyridine as a colourless oil (27.5 g, 88%). This material was used crude without further purification.

Quelle