Water → 6-(Benzyloxy)-2,3-dibromo-1-benzothiophene

HRID 732818Notes

Reaction equation

HRID 732818 reaction equation
[Br:1][C:2]1[S:6][C:5]2[CH:7]=[C:8]([OH:11])[CH:9]=[CH:10][C:4]=2[C:3]=1[Br:12].[H-].[Na+].[CH2:15](Br)[C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1.O>CN(C=O)C.C(OCC)(=O)C>[CH2:15]([O:11][C:8]1[CH:9]=[CH:10][C:4]2[C:3]([Br:12])=[C:2]([Br:1])[S:6][C:5]=2[CH:7]=1)[C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1

Participants

7

Reactant 4

HCID 962WaterHCID 7498Benzyl BromideHCID 24758Sodium hydrideHCID 690721602,3-Dibromo-benzo[b]thiophen-6-ol

Product 1

HCID 690752496-(Benzyloxy)-2,3-dibromo-1-benzothiopheneYield 92%

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolvent2×HCID 8857Ethyl AcetateSolvent

Procedure

Add a solution of 2,3-dibromo-benzo[b]thiophen-6-ol (43.9 g, 143 mmol) in DMF (1000 mL), dropwise, to a suspension of sodium hydride in DMF (1.5 L) at 0° C. Stir for 20 minutes, add benzyl bromide (17 mL, 143 mmol). Remove ice bath, and stir at room temperature for 2 hours. Pour reaction mixture into water (8 L) and ethyl acetate (4 L) and stir overnight. Separate layers and wash organic layer with water (3×800 mL) and brine (800 mL). Dry with sodium sulfate, filter, and concentrate in vacuo to give 52.4 g of 6-benzyloxy-2,3-dibromo-benzo[b]thiophene (92%).

Workup

  1. stirringRemove ice bath, and stir at room temperature for 2 hours
  2. additionPour
  3. stirringstir overnight
  4. washSeparate layers and wash organic layer with water (3×800 mL) and brine (800 mL)
  5. dry with materialDry with sodium sulfate
  6. filtrationfilter
  7. concentrationconcentrate in vacuo

Sources & evidence

ORD record
ord-a1f7a1a496b846c1bc39cc77fa09d9b3
Source dataset
uspto-grants-2009_09
Patent number
US07585977B2

Reaction notes

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