Reaktion #80920

Reaktionsgleichung

tributyltin chloride

2-bromo-5-chlorothiophene

n-butyllithium

→

(5-chlorothien-2-yl)tributyl tin

Ausbeute 98.1%

Lösungsmittel

tetrahydrofuran

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe reaction mixture temperature was maintained at -85° C. to -80° C. throughout the addition
2. 2
   workup.ADDITIONUpon completion of addition
3. 3
   workup.ADDITIONUpon completion of addition
4. 4
   Temperaturto warm gradually to ambient temperature
5. 5
   SonstigeThe reaction was quenched with an aqueous solution saturated with ammonium chloride
6. 6
   Extraktionthe reaction mixture was extracted with three 150 mL portions of diethyl ether
7. 7
   TrocknenThe combined extracts were dried with magnesium sulfate
8. 8
   Filtrationfiltered
9. 9
   EinengenThe filtrate was concentrated under reduced pressure

Vorschrift

A stirred solution of 5.1 mL (0.046 mole) of 2-bromo-5-chlorothiophene in 200 mL of tetrahydrofuran was cooled to -85° C., and 19.7 mL (0.049 mole) of n-butyllithium (0.049 mole-2.5M in hexanes) was added dropwise during a 15 minute period. The reaction mixture temperature was maintained at -85° C. to -80° C. throughout the addition. Upon completion of addition, the reaction mixture temperature was maintained at about -80° C. for one hour. After this time, a solution of 12.5 mL (0.046 mole) of tributyltin chloride in 50 mL of tetrahydrofuran was added to the cold reaction mixture during a 10 minute period. Upon completion of addition, the reaction mixture was stirred at -80° C. for one hour, then it was allowed to warm gradually to ambient temperature. The reaction was quenched with an aqueous solution saturated with ammonium chloride, and then the reaction mixture was extracted with three 150 mL portions of diethyl ether. The combined extracts were dried with magnesium sulfate and filtered. The filtrate was concentrated under reduced pressure, yielding 18.4 grams of (5-chlorothien-2-yl)tributyl tin. The NMR spectrum was consistent with the proposed structure.

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