Phosphorus tribromide → 2-(Bromomethyl)-1,4-difluorobenzene

HRID 883984Notes

Reaction equation

HRID 883984 reaction equation
[F:1][C:2]1[CH:7]=[CH:6][C:5]([F:8])=[CH:4][C:3]=1[CH2:9]O.P(Br)(Br)[Br:12].C(=O)(O)[O-].[Na+]>ClCCl>[Br:12][CH2:9][C:3]1[CH:4]=[C:5]([F:8])[CH:6]=[CH:7][C:2]=1[F:1]

Participants

5

Reactant 3

HCID 24614Phosphorus tribromideHCID 516892Sodium BicarbonateHCID 5225992,5-Difluorobenzyl alcohol

Product 1

HCID 5228302-(Bromomethyl)-1,4-difluorobenzeneYield 50.3%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of (2,5-difluoro-phenyl)-methanol (4.8 g, 33.6 mmol) in dichloromethane (40 mL) was added drop wise phosphorus tribromide (94 g, 33.6 mmol). The mixture was stirred at room temperature for 16 h. The reaction was poured onto ice/water. The aqueous phase was made basic with sodium bicarbonate. The aqueous phase was extracted with dichloromethane. The organic phase was concentrated under reduced pressure. The residue was purified by silica gel chromatography eluting with (hexanes/ethyl acetate 90:10) to give the title compound (3.5 g, 50%).

Workup

  1. additionThe reaction was poured onto ice/water
  2. extractionThe aqueous phase was extracted with dichloromethane
  3. concentrationThe organic phase was concentrated under reduced pressure
  4. customThe residue was purified by silica gel chromatography
  5. washeluting with (hexanes/ethyl acetate 90:10)

Sources & evidence

ORD record
ord-1d4ce03068a14268a128559122c91591
Source dataset
uspto-grants-2012_08
Patent number
US08236950B2

Reaction notes

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