Benzo(B)Thiophene → HCID 19785619, compound

HRID 654899Notes

Reaction equation

HRID 654899 reaction equation
[S:1]1[CH:5]=[CH:4][C:3]2[CH:6]=[CH:7][CH:8]=[CH:9][C:2]1=2.C([Li])CCC.[Br:15][CH2:16][CH2:17][CH2:18][CH2:19][CH2:20][CH2:21]Br>O1CCCC1.CCCCCC>[S:1]1[C:5]([CH2:21][CH2:20][CH2:19][CH2:18][CH2:17][CH2:16][Br:15])=[CH:4][C:3]2[CH:6]=[CH:7][CH:8]=[CH:9][C:2]1=2

Participants

6

Reactant 3

HCID 7221Benzo(B)ThiopheneHCID 123681,6-DibromohexaneHCID 178418339Butyllithium

Product 1

HCID 19785619HCID 19785619, compound

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolvent2×HCID 8058HexaneSolvent

Procedure

To a stirred solution of benzo[b]thiophene (1.92 g., 14.3 mmol) in 90 ml anhydrous tetrahydrofuran at -10° to 0° under argon was added n-butyllithium (7.8 ml of a 1.86M solution in hexane). After two hours, this solution was transferred dropwise into a stirred, 0° solution of 1,6-dibromohexane (6.5 ml, 0.043 mol) in 250 ml tetrahydrofuran. The solution was warmed to room temperature, stirred for 15 hours, quenched with water and concentrated. The residue was acidified and partitioned between ethyl ether and water. The aqueous portion was extracted twice with ether, and the combined organic portions were washed with water, saturated sodium chloride solution, dried over magnesium sulfate, filtered and concentrated to give a brown oil. Excess benzo[b]thiophene and 1,6-dibromohexane were removed by bulb to bulb distillation (85° to 90°/0.1 mm) to leave a dark brown syrup. This material was purified by flash chromatography (silica, hexane to 5% ethyl ether/hexane) to give the desired alkyl halide.

Workup

  1. customquenched with water
  2. concentrationconcentrated
  3. custompartitioned between ethyl ether and water
  4. extractionThe aqueous portion was extracted twice with ether
  5. washthe combined organic portions were washed with water, saturated sodium chloride solution
  6. dry with materialdried over magnesium sulfate
  7. filtrationfiltered
  8. concentrationconcentrated
  9. customto give a brown oil
  10. customExcess benzo[b]thiophene and 1,6-dibromohexane were removed by bulb to bulb distillation (85° to 90°/0.1 mm)
  11. customto leave a dark brown syrup
  12. customThis material was purified by flash chromatography (silica, hexane to 5% ethyl ether/hexane)

Sources & evidence

ORD record
ord-4dbfce71d5c24cf1862fad062a486899
Source dataset
uspto-grants-1992_07
Patent number
US05134128

Reaction notes

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