3-Bromo-1,2,4,5-tetrafluorobenzene → HCID 22015888, compound

HRID 1440959Notes

Reaction equation

Br[C:2]1[C:7]([F:8])=[C:6]([F:9])[CH:5]=[C:4]([F:10])[C:3]=1[F:11].C([Li])CCC.FC(F)(F)S(O[Si:23]([C:26]([CH3:29])([CH3:28])[CH3:27])([CH3:25])[CH3:24])(=O)=O>C(OCC)C>[CH3:24][Si:23]([CH3:25])([C:26]([CH3:29])([CH3:28])[CH3:27])[C:2]1[C:7]([F:8])=[C:6]([F:9])[CH:5]=[C:4]([F:10])[C:3]=1[F:11]

Participants

Conditions

Temperature: -78 °C

Procedure

The compound, 1-bromo-2,3,5,6-tetrafluorobenzene, C6HBrF4, (14.8 g, 64.6 mmol) was dissolved in diethyl ether (200 ml) in a 500 ml flask and was cooled down to -78° C. Butyllithium (40 ml, 1.6M in hexanes) was then added to the flask dropwise while the solution was being stirred vigorously. After it had been stirred for one hour, t-butyldimethylsilyl trifluoromethane sulfonate (17.0 g, 64.6 mmol) was injected via a syringe. The reaction mixture was allowed to slowly warm up to room temperature over a period of eight hours, and the resulting suspension was filtered. After the solvent was removed from the filtrate at 25° C. under reduced pressure, the nonvolatile residue was distilled and a colorless liquid product was collected (45°C./0.8 mm Hg). Yield, 80%, 1H NMR(CCl2D2): δ0.40 (t, 6H), 0.93 (s, 9H), 7.10 (m, 1H); 13C NMR(CCl2D2): δ -3.7(t), 18.1(s) , 26.5(s) , 108.0(t), 144.8(m), 148.1(t), 151.4(t).

Workup

stirringAfter it had been stirred for one hour
temperatureto slowly warm up to room temperature over a period of eight hours
filtrationthe resulting suspension was filtered
customAfter the solvent was removed from the filtrate at 25° C. under reduced pressure
distillationthe nonvolatile residue was distilled
customa colorless liquid product was collected (45°C./0.8 mm Hg)
customYield

Sources & evidence

ORD record: ord-5bc582e73d804ba38451308e532ba086
Source dataset: uspto-grants-1996_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05502017

Reaction notes

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