Reaktion #80470

Reaktionsgleichung

LDA

2-bromothiophene

4-fluorobenzyl bromide

HCl

→

2-bromo-5-(4-fluorophenylmethyl)thiophene

Ausbeute 45.1%

Lösungsmittel

THF

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGstirred for 70 hours
2. 2
   Extraktionextracted twice with ether
3. 3
   WaschenThe combined organic layers were washed with saturated aqueous NaHCO3 (2×) and brine
4. 4
   Trocknendried over MgSO4
5. 5
   Filtrationfiltered
6. 6
   Einengenconcentrated in vacuo

Vorschrift

To a -78° C. solution of LDA (19.3 mmol) in THF was added 2-bromothiophene (3.00 g, 18.4 mmol) and the reaction mixture was stirred for 15 min. A solution of 4-fluorobenzyl bromide (3.65 g, 19.3 mmol) in THF (1 mL) was added dropwise and the reaction mixture was warmed slowly to ambient temperature and stirred for 70 hours. The reaction mixture was poured into 0.5N aqueous HCl and extracted twice with ether. The combined organic layers were washed with saturated aqueous NaHCO3 (2×) and brine, dried over MgSO4, filtered, and concentrated in vacuo. Chromatography on silica gel (hexanes, then 3% ether/hexanes) gave 2-bromo-5-(4-fluorophenylmethyl)thiophene (2.25 g, 45%).

Quelle