Benzyl Bromide → 2-(2-Benzyloxy-ethyl)-3-bromo-benzo[b]thiophene

HRID 746624Notes

Reaction equation

HRID 746624 reaction equation
[Br:1][C:2]1[C:3]2[CH:13]=[CH:12][CH:11]=[CH:10][C:4]=2[S:5][C:6]=1[CH2:7][CH2:8][OH:9].[H-].[Na+].[CH2:16](Br)[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1>CN(C=O)C>[CH2:16]([O:9][CH2:8][CH2:7][C:6]1[S:5][C:4]2[CH:10]=[CH:11][CH:12]=[CH:13][C:3]=2[C:2]=1[Br:1])[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1

Participants

5

Reactant 3

HCID 7498Benzyl BromideHCID 24758Sodium hydrideHCID 821949HCID 821949, compound

Product 1

HCID 585915582-(2-Benzyloxy-ethyl)-3-bromo-benzo[b]thiopheneYield 87.6%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
0 °C

Procedure

To a cooled solution (0° C.) of 2-(3-bromo-benzo[b]thiophen-2-yl)-ethanol (7.7 g, 29.9 mmol) in DMF (40 mL), NaH (1.44 g, 59.8 mmol, 95%) was added and the mixture was stirred for 20 min at 0° C. Subsequently benzylbromide (5.3 mL, 45 mmol) was added and the mixture was stirred overnight while the temperature gradually reached room temperature. After quenching with MeOH, the mixture was concentrated in vacuo, dissolved in EtOAc, washed with sat NaHCO3, brine, dried (Na2SO4) and concentrated in vacuo. Purification by silica gel column chromatography (eluent: EtOAc/Hexanes=1/1) afforded 9.1 g of 2-(2-benzyloxy-ethyl)-3-bromo-benzo[b]thiophene (87% yield).

Workup

  1. stirringthe mixture was stirred overnight while the temperature gradually reached room temperature
  2. customAfter quenching with MeOH
  3. concentrationthe mixture was concentrated in vacuo
  4. dissolutiondissolved in EtOAc
  5. washwashed
  6. dry with materialdried (Na2SO4)
  7. concentrationconcentrated in vacuo
  8. customPurification by silica gel column chromatography (eluent: EtOAc/Hexanes=1/1)

Sources & evidence

ORD record
ord-c671ffe1551b4822ac34247c47b82dc2
Source dataset
uspto-grants-2008_07
Patent number
US07393865B2

Reaction notes

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