1,6-Dibromohexane → 1-(6-Bromohexyl)-2,3-dimethoxy-4-(1,1-dimethylethyl)benzene

HRID 1494261Notes

Reaction equation

HRID 1494261 reaction equation
[CH3:1][O:2][C:3]1[CH:8]=[CH:7][CH:6]=[C:5]([C:9]([CH3:12])([CH3:11])[CH3:10])[C:4]=1[O:13][CH3:14].C([Li])CCC.[Br:20][CH2:21][CH2:22][CH2:23][CH2:24][CH2:25][CH2:26]Br>O1CCCC1.CCCCCC>[Br:20][CH2:21][CH2:22][CH2:23][CH2:24][CH2:25][CH2:26][C:8]1[CH:7]=[CH:6][C:5]([C:9]([CH3:11])([CH3:10])[CH3:12])=[C:4]([O:13][CH3:14])[C:3]=1[O:2][CH3:1]

Participants

6

Reactant 3

HCID 123681,6-DibromohexaneHCID 12950402HCID 12950402, compoundHCID 178418339Butyllithium

Product 1

HCID 149864411-(6-Bromohexyl)-2,3-dimethoxy-4-(1,1-dimethylethyl)benzeneYield 15%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolvent2×HCID 8058HexaneSolvent

Procedure

To 27.0 g (0.139 mole) of 1,2-dimethoxy-3-(1,1-dimethylethyl)benzene in 350 mL of anhydrous tetrahydrofuran cooled in an ice-brine bath at -5° was added. 87 mL (0.139 mole) of 1.6M butyl lithium in hexane over 30 minutes. The reaction mixture was stirred at -5° for 3 hours and then at reflux for 1 hour. After cooling in an ice bath, 21.5 mL (0.139 mole) of 1,6-dibromohexane in 75 mL of tetrahydrofuran was added dropwise. The reaction mixture was then stirred at reflux for 17 hours. The solvent was removed under reduced pressure, 50 mL of 3N hydrochloric acid was added and the product was extracted with ether. The extract was washed with sodium bicarbonate solution, dried and concentrated at reduced pressure to an oil. Purification by HPLC using 20% toluene-hexane gave 7.6 g ((15% yield) of 1-(6-bromohexyl)-2,3-dimethoxy-4-(1,1-dimethylethyl)benzene.

Workup

  1. additionwas added
  2. temperatureat reflux for 1 hour
  3. temperatureAfter cooling in an ice bath
  4. stirringThe reaction mixture was then stirred
  5. temperatureat reflux for 17 hours
  6. customThe solvent was removed under reduced pressure, 50 mL of 3N hydrochloric acid
  7. additionwas added
  8. extractionthe product was extracted with ether
  9. washThe extract was washed with sodium bicarbonate solution
  10. customdried
  11. concentrationconcentrated at reduced pressure to an oil
  12. customPurification by HPLC

Sources & evidence

ORD record
ord-c374b92fbf8045c0b99ec29fd43025a0
Source dataset
uspto-grants-1991_06
Patent number
US05025036

Reaction notes

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