Phosphorus tribromide → 1-(Benzyloxy)-4-bromo-2-(bromomethyl)benzene

HRID 1455973Notes

Reaction equation

HRID 1455973 reaction equation
[CH2:1]([O:8][C:9]1[CH:16]=[CH:15][C:14]([Br:17])=[CH:13][C:10]=1[CH2:11]O)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.P(Br)(Br)[Br:19]>C(OCC)C>[CH2:1]([O:8][C:9]1[CH:16]=[CH:15][C:14]([Br:17])=[CH:13][C:10]=1[CH2:11][Br:19])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

4

Reactant 2

HCID 24614Phosphorus tribromideHCID 897136(2-(Benzyloxy)-5-bromophenyl)methanol

Product 1

HCID 117832201-(Benzyloxy)-4-bromo-2-(bromomethyl)benzeneYield 85.4%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent2×

Procedure

A solution of 2-benzyloxy-5-bromobenzyl alcohol (14.75 g, 50.2 mmol) in anhydrous ethyl ether (150 ml) was cooled to 4° C. A solution of PBr3 (13.68 g, 50 mmol) in anhydrous ether (40 ml) was added dropwise keeping the temperature below 10° C. The reaction was allowed to warm to ambient temperature and stirred for 1 hour. The reaction was filtered through silica gel (200 g). The silica gel was washed with ethyl ether to remove all the product. The filtrate was washed with water (1×150 ml), aqueous saturated sodium hydrogen carbonate (1×150 ml) and brine (1×150 ml). The organic layer was dried (Na2 SO4) and evaporated to give 2-benzyloxy-5-bromobenzylbromide as a pale yellow oil (15.2 g, 85%) which crystallised on standing.

Workup

  1. customthe temperature below 10° C
  2. filtrationThe reaction was filtered through silica gel (200 g)
  3. washThe silica gel was washed with ethyl ether
  4. customto remove all the product
  5. washThe filtrate was washed with water (1×150 ml), aqueous saturated sodium hydrogen carbonate (1×150 ml) and brine (1×150 ml)
  6. customThe organic layer was dried (Na2 SO4)
  7. customevaporated

Sources & evidence

ORD record
ord-a23747a6ad8e46f992c6b97fc1204bd4
Source dataset
uspto-grants-1998_12
Patent number
US05843942

Reaction notes

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