1,4-Dibromo-2-(2-bromoethoxy)benzene → 6-Bromo-2,3-dihydro-1-benzofuran

HRID 874642Notes

Reaction equation

HRID 874642 reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5]([Br:8])=[CH:4][C:3]=1[O:9][CH2:10][CH2:11]Br.[Li]CCCC>C1COCC1.CCCCCC>[Br:8][C:5]1[CH:6]=[CH:7][C:2]2[CH2:11][CH2:10][O:9][C:3]=2[CH:4]=1

Participants

5

Reactant 2

HCID 114738351,4-Dibromo-2-(2-bromoethoxy)benzeneHCID 178418339Butyllithium

Product 1

HCID 112526166-Bromo-2,3-dihydro-1-benzofuranYield 98.5%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 8058HexaneSolvent

Conditions

Temperature
-78 °C

Procedure

1,4-dibromo-2-(2-bromoethoxy)benzene (136) (922 mg, 2.57 mmol) was dissolved in 25 ml dry THF. After cooled down to −78° C., a solution of 2.5M n-BuLi (1.23 ml, 1.2 q) in hexane was added dropwise. The reaction mixture was stirred at −78° C. for 4 h before poured into ice-water. After extracted twice with ethyl acetate, the org. phase was washed with brine, dried over sodium sulfate and then concentrated to give 504 mg (purity ca 80%) 6-bromo-2,3-dihydrobenzo[b]furan (137) as dark brow oil which was used directly for further reaction.

Workup

  1. extractionAfter extracted twice with ethyl acetate
  2. washphase was washed with brine
  3. dry with materialdried over sodium sulfate
  4. concentrationconcentrated

Sources & evidence

ORD record
ord-a9f701c857774c53b174c37a0dc1627d
Source dataset
uspto-grants-2015_03
Patent number
US08980629B2

Reaction notes

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