Reaktion #2353440

Reaktionsgleichung

iodine

1-bromo-3-fluoro-benzene

diisopropylamine

n-BuLi

→

1-bromo-3-fluoro-2-iodobenzene

Ausbeute 91.4%

Lösungsmittel

THF

THF

THF

n-hexane

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGAfter stirring for an additional 1 h at −78° C.
2. 2
   TemperaturThe temperature was raised from −78° C. to rt during 2 h
3. 3
   workup.STIRRINGAfter stirring for 18 h at rt
4. 4
   Einengenthe mixture was concentrated in vacuo
5. 5
   Sonstigeto give crude product (120 g) which
6. 6
   workup.DISTILLATIONwas distilled under reduced pressure

Vorschrift

To a solution of diisopropylamine (76 mL, 0.4 mol) in dry THF (664 mL) and n-hexane (220 mL) was added 2.5 M n-BuLi (160 mL. 0.4 mol) dropwise at −78° C. during a period of 1 h. The mixture was stirred for 1 h at −78° C. Then a solution of 1-bromo-3-fluoro-benzene (69 g, 0.4 mol) in dry THF (300 mL) at −78° C. was added to the above mixture dropwise. After stirring for an additional 1 h at −78° C., the mixture was added a solution of iodine (101 g, 0.4 mol) in dry THF (400 mL) dropwise at −78° C. The temperature was raised from −78° C. to rt during 2 h. After stirring for 18 h at rt, the mixture was concentrated in vacuo to give crude product (120 g) which was distilled under reduced pressure to afford 1-bromo-3-fluoro-2-iodobenzene (110 g). 1H NMR (400 MHz, DMSO): 7.24-7.19 (t, 1H), 7.38-7.32 (m, 1H), 7.55-7.53 (d, 1H).

Quelle