Phosphorus tribromide → 5-(2-Bromoethyl)-2,3-dihydro-1-benzofuran

HRID 21404Notes

Reaction equation

HRID 21404 reaction equation
P(Br)(Br)[Br:2].O[CH2:6][CH2:7][C:8]1[CH:9]=[CH:10][C:11]2[O:15][CH2:14][CH2:13][C:12]=2[CH:16]=1>C(Cl)(Cl)(Cl)Cl>[Br:2][CH2:6][CH2:7][C:8]1[CH:9]=[CH:10][C:11]2[O:15][CH2:14][CH2:13][C:12]=2[CH:16]=1

Participants

4

Reactant 2

HCID 24614Phosphorus tribromideHCID 212240782-(2,3-Dihydro-1-benzofuran-5-yl)ethan-1-ol

Product 1

HCID 218311605-(2-Bromoethyl)-2,3-dihydro-1-benzofuran

Reagents, catalysts & solvents 1

HCID 5943Carbon TetrachlorideSolvent

Procedure

Phosphorus tribromide (0.37 g) was added to a solution of 5-(2-hydroxyethyl)-2,3-dihydrobenzofuran (0.612 g) in carbon tetrachloride (3 ml) and the mixture heated under reflux for 3 hours. On cooling to room temperature, the mixture was partitioned between 10% aqueous sodium carbonate (20 ml) and dichloromethane (20 ml). The layers were separated and the aqueous layer extracted with dichloromethane (2×10 ml). The combined dichloromethane extracts were dried (MgSO4) and concentrated in vacuo to give the title compound as an oil which crystallised on standing, yield 0.584 g, m.p. 60°-62° C. 1H N.m.r. (CDCl3)δ=7.10 (s, 1H); 7.00-6.95 (d, 1H); 6.80-6.70 (d, 1H); 4.65-4.55 (t, 2H); 3.60-3.50 (t, 2H); 3.25-3.15 (t, 2H); 3.15-3.10 (t, 2H) ppm.

Workup

  1. temperaturethe mixture heated
  2. temperatureunder reflux for 3 hours
  3. customthe mixture was partitioned between 10% aqueous sodium carbonate (20 ml) and dichloromethane (20 ml)
  4. customThe layers were separated
  5. extractionthe aqueous layer extracted with dichloromethane (2×10 ml)
  6. dry with materialThe combined dichloromethane extracts were dried (MgSO4)
  7. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-29cdc76955eb41139754057aa2056c21
Source dataset
uspto-grants-1995_06
Patent number
US05422358

Reaction notes

Loading…